Cholinesterase activities and oxidative stress in cattle experimentally exposed to nitrate/nitrite in cultivated pasture with different fertilization schemes

Background: Nitrate and nitrite poisoning is associated with pasture intake that has high nitrate levels and leads to acute methemoglobinemia. Pasture may accumulate nitrate under certain conditions, such as excessively fertilized soil or environmental conditions that enhance the N absorption (rain preceded by a period of drought). After ingestion of plants, this substrate reaches the rumen and, in physiological conditions, is reduced to nitrite and afterward to ammonia. The aim of this study was to evaluate changes in cholinesterase activities and oxidative stress caused by subclinical poisoning for nitrate and nitrite in cattle fed with Pennisetum glaucum in three different fertilization schemes.Materials, Methods & Results: In order to perform the experimental poisoning, the pasture was cultivated in three different paddocks: with nitrogen topdressing (urea; group 1), organic fertilizer (group 2) or without fertilizer (group 3; control). Nitrate accumulation in forage was evaluated by the diphenylamine test. After food fasting of 12 h, nine bovine were randomly allocated to one of the experimental groups and fed with fresh forage (ad libitum) from respective paddock. In different time points from beginning of pasture intake (0, 2, 4, 6 and 9 h) heart rate and respiratory frequency were assessed, as well as mucous membrane color and behavioral changes. Blood samples from jugular vein into vials with and without anticoagulant were collected. From blood samples, serum nitrite levels, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzyme activity were evaluated, as well as oxidative stress through the following parameters: levels of nitrate/nitrite (NOx ), thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS), beyond the antioxidant system by enzyme activity measurement of catalase (CAT) and superoxide dismutase (SOD).[...]

Cholinesterase activities and oxidative stress in cattle experimentally exposed to nitrate/nitrite in cultivated pasture with different fertilization schemes

Background: Nitrate and nitrite poisoning is associated with pasture intake that has high nitrate levels and leads to acute methemoglobinemia. Pasture may accumulate nitrate under certain conditions, such as excessively fertilized soil or environmental conditions that enhance the N absorption (rain preceded by a period of drought). After ingestion of plants, this substrate reaches the rumen and, in physiological conditions, is reduced to nitrite and afterward to ammonia. The aim of this study was to evaluate changes in cholinesterase activities and oxidative stress caused by subclinical poisoning for nitrate and nitrite in cattle fed with Pennisetum glaucum in three different fertilization schemes.Materials, Methods & Results: In order to perform the experimental poisoning, the pasture was cultivated in three different paddocks: with nitrogen topdressing (urea; group 1), organic fertilizer (group 2) or without fertilizer (group 3; control). Nitrate accumulation in forage was evaluated by the diphenylamine test. After food fasting of 12 h, nine bovine were randomly allocated to one of the experimental groups and fed with fresh forage (ad libitum) from respective paddock. In different time points from beginning of pasture intake (0, 2, 4, 6 and 9 h) heart rate and respiratory frequency were assessed, as well as mucous membrane color and behavioral changes. Blood samples from jugular vein into vials with and without anticoagulant were collected. From blood samples, serum nitrite levels, acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) enzyme activity were evaluated, as well as oxidative stress through the following parameters: levels of nitrate/nitrite (NOx ), thiobarbituric acid reactive substances (TBARS) and reactive oxygen species (ROS), beyond the antioxidant system by enzyme activity measurement of catalase (CAT) and superoxide dismutase (SOD).[...](AU)

Rattlesnake Crotalus molossus nigrescens venom induces oxidative stress on human erythrocytes

Abstract Background Globally, snake envenomation is a well-known cause of death and morbidity. In many cases of snakebite, myonecrosis, dermonecrosis, hemorrhage and neurotoxicity are present. Some of these symptoms may be provoked by the envenomation itself, but others are secondary effects of the produced oxidative stress that enhances the damage produced by the venom toxins. The only oxidative stress effect known in blood is the change in oxidation number of Fe (from ferrous to ferric) in hemoglobin, generating methemoglobin but not in other macromolecules. Currently, the effects of the overproduction of methemoglobin derived from snake venom are not extensively recorded. Therefore, the present study aims to describe the oxidative stress induced by Crotalus molossus nigrescens venom using erythrocytes. Methods Human erythrocytes were washed and incubated with different Crotalus molossus nigrescens venom concentrations (0640 g/mL). After 24 h, the hemolytic activity was measured followed by attenuated total reflectance-Fourier transform infrared spectroscopy, non-denaturing PAGE, conjugated diene and thiobarbituric acid reactive substances determination. Results Low concentrations of venom ( 10 g/mL) generates oxyhemoglobin release by hemolysis, whereas higher concentrations produced a hemoglobin shift of valence, producing methemoglobin (>40 g/mL). This substance is not degraded by proteases present in the venom. By infrared spectroscopy, starting in 80 g/mL, we observed changes in bands that are associated with protein damage (1660 and 1540 cm1) and lipid peroxidation (2960, 2920 and 1740 cm1). Lipid peroxidation was confirmed by conjugated diene and thiobarbituric acid reactive substance determination, in which differences were observed between the control and erythrocytes treated with venom. Conclusions Crotalus molossus nigrescens venom provokes hemolysis and oxidative stress, which induces methemoglobin formation, loss of protein structure and lipid peroxidation.

Rattlesnake Crotalus molossus nigrescens venom induces oxidative stress on human erythrocytes

Background Globally, snake envenomation is a well-known cause of death and morbidity. In many cases of snakebite, myonecrosis, dermonecrosis, hemorrhage and neurotoxicity are present. Some of these symptoms may be provoked by the envenomation itself, but others are secondary effects of the produced oxidative stress that enhances the damage produced by the venom toxins. The only oxidative stress effect known in blood is the change in oxidation number of Fe (from ferrous to ferric) in hemoglobin, generating methemoglobin but not in other macromolecules. Currently, the effects of the overproduction of methemoglobin derived from snake venom are not extensively recorded. Therefore, the present study aims to describe the oxidative stress induced by Crotalus molossus nigrescens venom using erythrocytes. Methods Human erythrocytes were washed and incubated with different Crotalus molossus nigrescens venom concentrations (0-640 μg/mL). After 24 h, the hemolytic activity was measured followed by attenuated total reflectance-Fourier transform infrared spectroscopy, non-denaturing PAGE, conjugated diene and thiobarbituric acid reactive substances determination. Results Low concentrations of venom (<10 μg/mL) generates oxyhemoglobin release by hemolysis, whereas higher concentrations produced a hemoglobin shift of valence, producing methemoglobin (>40 μg/mL). This substance is not degraded by proteases present in the venom. By infrared spectroscopy, starting in 80 μg/mL, we observed changes in bands that are associated with protein damage (1660 and 1540 cm−1) and lipid peroxidation (2960, 2920 and 1740 cm−1). Lipid peroxidation was confirmed by conjugated diene and thiobarbituric acid reactive substance determination, in which differences were observed between the control and erythrocytes treated with venom. Conclusions Crotalus molossus nigrescens venom provokes hemolysis and oxidative stress, which induces methemoglobin formation, loss of protein structure and lipid peroxidation.(AU)

Rattlesnake Crotalus molossus nigrescens venom induces oxidative stress on human erythrocytes

Background Globally, snake envenomation is a well-known cause of death and morbidity. In many cases of snakebite, myonecrosis, dermonecrosis, hemorrhage and neurotoxicity are present. Some of these symptoms may be provoked by the envenomation itself, but others are secondary effects of the produced oxidative stress that enhances the damage produced by the venom toxins. The only oxidative stress effect known in blood is the change in oxidation number of Fe (from ferrous to ferric) in hemoglobin, generating methemoglobin but not in other macromolecules. Currently, the effects of the overproduction of methemoglobin derived from snake venom are not extensively recorded. Therefore, the present study aims to describe the oxidative stress induced by Crotalus molossus nigrescens venom using erythrocytes. Methods Human erythrocytes were washed and incubated with different Crotalus molossus nigrescens venom concentrations (0-640 μg/mL). After 24 h, the hemolytic activity was measured followed by attenuated total reflectance-Fourier transform infrared spectroscopy, non-denaturing PAGE, conjugated diene and thiobarbituric acid reactive substances determination. Results Low concentrations of venom (<10 μg/mL) generates oxyhemoglobin release by hemolysis, whereas higher concentrations produced a hemoglobin shift of valence, producing methemoglobin (>40 μg/mL). This substance is not degraded by proteases present in the venom. By infrared spectroscopy, starting in 80 μg/mL, we observed changes in bands that are associated with protein damage (1660 and 1540 cm−1) and lipid peroxidation (2960, 2920 and 1740 cm−1). Lipid peroxidation was confirmed by conjugated diene and thiobarbituric acid reactive substance determination, in which differences were observed between the control and erythrocytes treated with venom. Conclusions Crotalus molossus nigrescens venom provokes hemolysis and oxidative stress, which induces methemoglobin formation, loss of protein structure and lipid peroxidation.(AU)

Efeito de fontes de nitrato in vitro na produção de metano e do nitrato de cálcio na qualidade do leite de cabras e vacas

O objetivo deste trabalho foi avaliar o nitrato (NO3-) de cálcio e fontes adicionais de NO3- na produção in vitro de metano (CH4) e a suplementação do NO3- de cálcio para cabras e vacas em lactação. No primeiro estudo, foram avaliadas fontes de NO3- associadas a dietas com milho seco ou silagem de grão úmido como fonte principal de amido. Adotou-se o delineamento experimental em blocos ao acaso em um sistema fatorial 5 × 2, com cinco fontes de nitrogênio não proteico (NNP) denominados: URE, ureia (grupo controle); PON, nitrato de potássio; CAN, nitrato de cálcio; DON, nitrato dolomítico e AMN, nitrato de amônia, combinados a milho seco (MS) ou silagem de grão úmido de milho (SG). A degradabilidade da matéria seca (MS) e da fibra em detergente neutro (FDN) não foram afetadas pelas fontes de NO3-. A SG aumentou a proporção de propionato, reduziu a razão acetato:propionato e diminuiu a produção de CH4. A suplementação de NO3- reduziu a produção de CH4 em comparação a URE, mas sem diferenças entre as fontes utilizadas. Ao contrário da hipótese principal, não houve interação entre as fontes de NO3- e de amido para os parâmetros avaliados. Todas as fontes de NO3- foram eficazes em mitigar a produção de CH4 independentemente da taxa de degradação ruminal do amido. No segundo estudo, foram utilizadas 12 cabras Saanen em lactação, distribuídas em quatro quadrados latinos 3 × 3, com períodos de 21 dias, nos quais 14 dias foram destinados à adaptação dos animais as dietas e os últimos 7 dias para coleta de amostras e dados. Os tratamentos foram denominados: UREA, ureia (grupo controle); CAN10, 10 g de nitrato de cálcio (7.65 g/kg de NO3- na MS) e CAN20, 20 g de nitrato de cálcio (15.3 g/kg de NO3- na MS). A ingestão de MS e a digestibilidade dos nutrientes não foram afetadas pela suplementação de CAN. Não houve efeito do NO3- na produção, composição e perfil de ácidos graxos do leite. A capacidade total antioxidante do leite não foi afetada pelos tratamentos, enquanto a oncentração dos dienos conjugados reduziram e os TBARS aumentaram. As concentrações de NO3- e nitrito (NO2-) residuais no leite foram aumentadas em função dos tratamentos. Os tratamentos não afetaram as proporções e o total de ácidos graxos voláteis (AGV) no rúmen, assim como a concentração de nitrogênio amoniacal (NH3-N). O nitrato de cálcio pode ser suplementado para cabras em lactação em até 20 g/kg de MS sem afetar a fermentação ruminal e a qualidade do leite. No terceiro estudo, avaliou-se a suplementação de CAN na dieta de vacas em lactação. Foram utilizadas seis vacas da raça Holandês distribuídas em dois quadrados latinos 3 × 3, com períodos de 21 dias cada, nos quais 14 dias foram destinados à adaptação dos animais e os demais para coleta de amostras e dados. Os tratamentos foram denominados UREA, grupo controle; CAN15, 15 g de nitrato de cálcio (11.5 g/kg de NO3- na MS) e CAN30: 30 g de nitrato de cálcio (23 g/kg de NO3- na MS). A suplementação de nitrato de cálcio reduziu o consumo de matéria seca, mas não afetou a digestibilidade dos nutrientes. Não houve efeito dos tratamentos na produção de leite, no entanto, houve redução na produção de leite corrigido para energia e gordura. Foram observados níveis residuais de NO3- e NO2- no leite, assim como baixos níveis de metemoglobina no sangue. A quantidade de gordura no leite foi reduzida pelos tratamentos, assim como a proporção dos ácidos graxos saturados. O poder redutor e a concentração de TBARS não foram afetadas pelos tratamentos, enquanto os dienos conjugados aumentaram linearmente. A síntese de proteína microbiana não foi afetada pelos tratamentos e poucos efeitos foram observados nos parâmetros de fermentação ruminal. Devido ao impacto no consumo e qualidade do leite ao nível de 30 g/kg MS de CAN recomendou-se a suplementação de até 15 g/ kg MS de CAN para vacas leiteiras sem afetar a qualidade do leite e os parâmetros fermentativos.

The objectives were to evaluate the effects of calcium nitrate (NO3-) and additional sources of NO3- on in vitro methane (CH4) production and calcium nitrate supplementation for dairy goats and cows. In the first study, NO3- sources were associated with diets receiving either dry rolled corn (DRC) or high moisture corn (HMC) as the main source of starch. The experiment followed a randomized complete block design with a 5 × 2 factorial arrangement. Treatment were the sources of non-protein nitrogen (NPN) designed as: URE, urea; PON, potassium nitrate; CAN, calcium nitrate; DON, dolomite nitrate and AMN, ammonium nitrate) and starch sources (DRC, dry rolled corn and HMC, high moisture corn). The degradability of dry matter (DM) and neutral detergent fiber (NDF) were not affected by the sources of NO3-. The HMC increased propionate proportion, reduced the acetate: propionate ratio, and decreased CH4 production. Methane production was reduced by NO3- compared to the control group regardless of the sources. Contrary to our main hypothesis, there was no interaction between NO3- and starch sources in all parameters. All NO3- sources were effective at mitigating CH4 production regardless of the rate ruminal starch degradation. In the second study, 12 Saanen goats were enrolled in four 3 × 3 Latin squares. Each period lasted 21 days, with 14 days used as an adaptation phase and the last 7 days for sampling and data collection. Treatments were designed as: UREA, as a control group; CAN10, 10 g of calcium nitrate (7.65 g/kg of NO3- on DM basis) and CAN20, 20 g of calcium nitrate (15.3 g/kg of NO3- on DM basis). Dry matter intake and nutrient digestibility were not affected by CAN supplementation. There were no effects of CAN on milk production, composition, and milk fatty acids. Milk total antioxidant capacity was not affected by treatment, while the concentration of conjugated dienes decreased and TBARS increased. Residual concentrations of NO3- and nitrite (NO2-) in milk were affected by the treatment, but it did not affect the proportions and total volatile fatty acids into the rumen, as well as the ammonianitrogen concentration. Calcium nitrate can be supplemented to lactating goats up to 20 g/kg DM without affecting ruminal fermentation and milk quality. Lastly, responses of CAN supplementation fed to dairy cows were evaluated. Six Holstein cows were enrolled in a replicated 3 × 3 Latin square design, with periods of 21 days, including 14 days for the adaptation of the animals and the remaining days for sampling and data collection. Treatments were designed as: UREA, as a control group; CAN15, 15 g of calcium nitrate (11.5 g/kg of NO3- on DM basis) and CAN30: 30 g of calcium nitrate (23 g/kg of NO3- on DM basis). Supplemental CAN reduced nutrient intake, but it did not affect nutrient digestibility. Treatment did not affect milk production; however, energy-corrected milk and fat-corrected milk decreased as the levels of CAN increased. Low levels of residual NO3- and NO2- were detected in milk, as well as the levels of methemoglobin in blood, although the latter has increased linearly. Milk fat content was negatively affected by CAN, and the proportion of saturated fatty acids decreased. Reducing power and TBARS concentration were not affected by the CAN, while conjugated dienes increased. Microbial protein synthesis was not affected by supplemental CAN and minor effects were observed on rumen fermentation parameters. Because of the negative effect of CAN on milk contents and quality at 30 g/kg DM, it was recommended the supplementation of 15 g/kg DM of CAN for dairy cows without affecting milk quality and fermentation parameters.

Nitrate in ruminant feeding mitigates methane production / Nitrato na alimentação de ruminantes mitiga a produção de metano

Methane and carbon dioxide are natural products of microbial fermentation primarily of carbohydrates and lesser extent of amino acids in rumen and intestine of the animals. The main factor affecting methane production in ruminants is the food, due to providing substrate for methanogenic bacteria. Changes in animal nutrition through the use of strategic resources, with a balanced diet based on the physiological needs of animals contributes to the reduction of methane production. Nitrate when added in ruminant diet promotes the use of hydrogen ions for its conversion to ammonia. Some microorganisms are able to reduce nitrate to nitrite and then nitrite to ammonia using hydrogen, and therefore methanogenesis can be reduced. However, the supply of nitrate, without an adaptation period, in levels that exceed the ruminant capacity to use it can lead to the occurrence of methemoglobinemia. To avoid poisoning is recommended an adaptation period of animals to the nitrate content.(AU)  

O metano e o dióxido de carbono são subprodutos naturais da fermentação microbiana principalmente de carboidratos e em menor extensão dos aminoácidos no rúmen e no intestino grosso dos animais. O fator primário que afeta a produção de metano pelos ruminantes é a alimentação, pelo fato de fornecer substrato para as bactérias metanogênicas. Mudanças na alimentação dos animais através do uso estratégico de recursos disponíveis, com uma dieta equilibrada com base nas necessidades fisiológicas dos animais contribui com a redução da produção de metano. O nitrato quando fornecido na dieta de ruminantes promove o uso de íons hidrogênio para sua conversão em amônia. Alguns microrganismos são capazes de reduzir nitrato a nitrito e então nitrito a amônia com o uso de hidrogênio, assim a metanogênese pode ser reduzida. No entanto, o fornecimento de nitrato, em teores excessivos para ruminantes, sem cuidados quanto à adaptação dos animais as dietas, pode levar a ocorrência de metahemoglobinemia. Para evitar a intoxicação recomenda-se que haja adaptação dos animais aos teores de nitrato.(AU)

Nitrate in ruminant feeding mitigates methane production / Nitrato na alimentação de ruminantes mitiga a produção de metano

Methane and carbon dioxide are natural products of microbial fermentation primarily of carbohydrates and lesser extent of amino acids in rumen and intestine of the animals. The main factor affecting methane production in ruminants is the food, due to providing substrate for methanogenic bacteria. Changes in animal nutrition through the use of strategic resources, with a balanced diet based on the physiological needs of animals contributes to the reduction of methane production. Nitrate when added in ruminant diet promotes the use of hydrogen ions for its conversion to ammonia. Some microorganisms are able to reduce nitrate to nitrite and then nitrite to ammonia using hydrogen, and therefore methanogenesis can be reduced. However, the supply of nitrate, without an adaptation period, in levels that exceed the ruminant capacity to use it can lead to the occurrence of methemoglobinemia. To avoid poisoning is recommended an adaptation period of animals to the nitrate content.

O metano e o dióxido de carbono são subprodutos naturais da fermentação microbiana principalmente de carboidratos e em menor extensão dos aminoácidos no rúmen e no intestino grosso dos animais. O fator primário que afeta a produção de metano pelos ruminantes é a alimentação, pelo fato de fornecer substrato para as bactérias metanogênicas. Mudanças na alimentação dos animais através do uso estratégico de recursos disponíveis, com uma dieta equilibrada com base nas necessidades fisiológicas dos animais contribui com a redução da produção de metano. O nitrato quando fornecido na dieta de ruminantes promove o uso de íons hidrogênio para sua conversão em amônia. Alguns microrganismos são capazes de reduzir nitrato a nitrito e então nitrito a amônia com o uso de hidrogênio, assim a metanogênese pode ser reduzida. No entanto, o fornecimento de nitrato, em teores excessivos para ruminantes, sem cuidados quanto à adaptação dos animais as dietas, pode levar a ocorrência de metahemoglobinemia. Para evitar a intoxicação recomenda-se que haja adaptação dos animais aos teores de nitrato.

Intoxicação por paracetamol em gatos / Acetaminophen toxicity in cats

intoxicação por paracetamol em gatos ocorre por exposição acidental ou de forma iatrogênica, quando um responsável o administra na intenção de tratar seu animal. Os gatos apresentam defi ciência em sua biotransformação e por isso mesmo pequenas doses do fármaco podem provocar sinais de intoxicação. Dentre os sinais clínicos pode-se observar cianose, depressão, icterícia, edema de face e membros, taquipnéia, dispnéia, anorexia, fraqueza, vômito, hipotermia e hematúria. Felizmente, com um tratamento agressivo e cuidado de suporte adequado, a maioria dos animais se recupera completamente. O proprietário deve ser orientado a nunca administrar paracetamol em gatos. Considerando a grande quantidade de gatos atendidos na emergência veterinária com sinais clínicos de intoxicação por paracetamol, tem-se por objetivo apresentar informações sobre essa enfermidade para que os clínicos de pequenos animais possam identifi car o quadro e assim tratá-lo com sucesso.

Paracetamol intoxication in cats occurs due to accidental or iatrogenic exposure, when the owners administers the medication with the intention of treating their pet. Cats are defi cient in terms of biotransformation, so even small doses of the drug can cause toxicity. Among the clinical signs, cyanosis, depression, icterus, edema of face and limbs, tachypnea, dyspnea, anorexia, weakness,vomiting, hypothermia and hematuria can be observed. Fortunately, with aggressive treatment and appropriate supportive care, most animals are able to recover completely. Owners should be advised not to administer acetaminophen in cats. Considering the large number of cats treated in emergency veterinary with clinical signs of acetaminophen toxicity, we have the objective of presenting information about this disease for clinicians of small animals to identify the framework and thus treat it successfully.

Intoxicação por paracetamol em gatos / Acetaminophen toxicity in cats

intoxicação por paracetamol em gatos ocorre por exposição acidental ou de forma iatrogênica, quando um responsável o administra na intenção de tratar seu animal. Os gatos apresentam defi ciência em sua biotransformação e por isso mesmo pequenas doses do fármaco podem provocar sinais de intoxicação. Dentre os sinais clínicos pode-se observar cianose, depressão, icterícia, edema de face e membros, taquipnéia, dispnéia, anorexia, fraqueza, vômito, hipotermia e hematúria. Felizmente, com um tratamento agressivo e cuidado de suporte adequado, a maioria dos animais se recupera completamente. O proprietário deve ser orientado a nunca administrar paracetamol em gatos. Considerando a grande quantidade de gatos atendidos na emergência veterinária com sinais clínicos de intoxicação por paracetamol, tem-se por objetivo apresentar informações sobre essa enfermidade para que os clínicos de pequenos animais possam identifi car o quadro e assim tratá-lo com sucesso.(AU)

Paracetamol intoxication in cats occurs due to accidental or iatrogenic exposure, when the owners administers the medication with the intention of treating their pet. Cats are defi cient in terms of biotransformation, so even small doses of the drug can cause toxicity. Among the clinical signs, cyanosis, depression, icterus, edema of face and limbs, tachypnea, dyspnea, anorexia, weakness,vomiting, hypothermia and hematuria can be observed. Fortunately, with aggressive treatment and appropriate supportive care, most animals are able to recover completely. Owners should be advised not to administer acetaminophen in cats. Considering the large number of cats treated in emergency veterinary with clinical signs of acetaminophen toxicity, we have the objective of presenting information about this disease for clinicians of small animals to identify the framework and thus treat it successfully.(AU)

Intoxicação experimental por Indigofera suffruticosa em caprinos e ovinos / Experimental poisoning by Indigofera suffruticosa in goats and sheep

Indigofera suffruticosa é uma planta invasora, ção. Em um caprino e um ovino foram realizados os testes que causa anemia hemolítica com hemoglobinúria em bo-de fragilidade osmótica, determinação de hemoglobina e vinos e, experimentalmente, anemia sem hemoglobinúria metemoglobina e pesquisa de corpúsculos de Heinz. Foi em cobaios. O objetivo deste trabalho foi determinar a comprovado que em caprinos e ovinos, I. suffruticosa cautoxicidade de I. suffruticosa para caprinos e ovinos. Par-sa anemia hemolítica sem hemoglobinúria com formação tes aéreas da planta foram administradas a seis caprinos de corpúsculos de Heinz. Os animais recuperaram-se da e quatro ovinos em doses diárias de 10, 20 e 40g por kg anemia, total ou parcialmente, mesmo com a continuidade de peso vivo, durante períodos de 2 a 24 dias. Foram ava-da administração da planta. Oito a 12 horas após a coleliados os parâmetros hematológicos (hematócrito, níveis ta observa-se pigmento azulado na urina. Sugere-se que o de hemoglobina e contagem de hemácias) e foi coletada pigmento seja anilina ou algum metabolito dessa substânurina para urinálise e observação de variações na coloracia e que a anilina seja o princípio ativo responsável pela hemólise causada por I. suffruticosa.(AU)

Indigofera suffruticosa is a weed, which causes hemolytic anemia and hemoglobinuriain cattle and, experimentally, anemia without hemoglobinuria in guinea pigs. With the objective to determinate the toxicity of I. suffruticosa to sheep and goats aerial parts of the plant were administrated to six goats and four sheep at daily doses of 10, 20 and 40g of fresh plant per kg body weight, during two to 24 days. Blood samples were collected daily for the determination of packed cell volume, hemoglobin concentrations, and red blood cells count. Urine was also collected daily for urine examination and observation of color changes. Osmotic fragility and blood concentrations of hemoglobin and methemoglobin were determined in one goat and one sheep. Anemia due to extravascular hemolysis, without hemoglobinuria, was observed in the experimental sheep and goats. Heinz bodies were observed in brilliant cresyl blue stained blood smears. There was total or partial recovery of the anemia in spite of the continued plant administration. Eight to 12 hours after collection a bluish pigment was observed in the urine. It is suggested that aniline is thetoxic compound of I. suffruticosa responsible for the hemolysis.(AU)

Allium species poisoning in dogs and cats

Dogs and cats are the animals that owners most frequently seek assistance for potential poisonings, and these species are frequently involved with toxicoses due to ingestion of poisonous food. Feeding human foodstuff to pets may prove itself dangerous for their health, similarly to what is observed in Allium species toxicosis. Allium species toxicosis is reported worldwide in several animal species, and the toxic principles present in them causes the transformation of hemoglobin into methemoglobin, consequently resulting in hemolytic anemia with Heinz body formation. The aim of this review is to analyze the clinicopathologic aspects and therapeutic approach of this serious toxicosis of dogs and cats in order to give knowledge to veterinarians about Allium species toxicosis, and subsequently allow them to correctly diagnose this disease when facing it; and to educate pet owners to not feed their animals with Allium-containg food in order to better control this particular life-threatening toxicosis.(AU)

NITRATO ENCAPSULADO EM SUBSTITUIÇÃO AO FARELO DE SOJA NA TERMINAÇÃO DE BOVINOS DE CORTE EM CONFINAMENTO

Objetivou-se avaliar a inclusão crescente de nitrato encapsulado (ENP) como fonte de nitrogênio não proteico em substituição do farelo de soja sobre variáveis de digestibilidade, desempenho, resíduos de nitrato e nitrito na carne, variáveis de comportamento ingestivo, metemoglobina e os constituintes sanguíneos de novilhos terminados em confinamento. Cento e vinte novilhos não castrados (339,5 ± 28,3 kg) foram divididos em grupos de 6 animais, alojados em 20 baias e distribuídos em um delineamento em blocos casualizados com 5 blocos e 4 tratamentos: Controle (CTL) - farelo de soja; ENP-1 - 1% ENP (0,65% NO 3 -) na MS da dieta; ENP-2 - 2% ENP (1,30% NO 3 -); ENP-3-3% ENP (1,95% NO 3 -). As dietas foram compostas com relação 90:10 concentrado: forragem (bagaço de cana in natura). O experimento durou 84 dias. O consumo de matéria seca diminuiu linearmente (9,6-8,4 kg / dia; P<0,05) com a adição de quantidades crescentes de nitrato encapsulado na dieta dos novilhos. No entanto, rendimento de carcaça e espessura de gordura não foram influenciados (P>0,05) pelos tratamentos. Houve tendência quadrática (0,121, 0,130, 0,128, 0,127, respectivamente; P = 0,07) para ganho em carcaça. A concentração de nitratos na carne aumentou linearmente (3,48, 2,73, 3,98, 6,59 mg NO 3 -/ kg de carne fresca; P = 0,02) com a adição ENP, embora nitrito (NO 2 -) não foi detectado. Houve uma tendência para a redução quadrática (P=0,07) no tempo por unidade de ingestão de matéria seca e redução quadrática (P<0,01) quando expressa numa base de ruminação de FDN. Efeito quadrático na mastigação foram observados por unidade de ingestão de matéria seca (P=0,03) e consumo de FDN (P<0,01). A concentração sanguínea de metahemoglobina aumentou de forma linear (P<0,05) com a adição crescente do produto nitrato encapsulado, mas não atingiu valores que caracterizam risco de intoxicação. Para as variáveis sanguíneas (creatinina, fosfatase alcalina, proteína total, albumina, e glicose) não obtiveram efeitos (P>0,05) para os tratamentos. Entretanto, houve um efeito quadrático (P<0,01) para triglicérideos no sangue, e aumento linear para o colesterol total (P=0,05), as variáveis ureia (P<0,01), aspartato aminotransferase (P <0,01) e gama-glutamil transferase (P=0,04) resultaram em efeito linear decrescente. A digestibilidade aparente de nutrientes teve efeito quadrático para todos os nutrientes com os níveis crescentes de nitrato encapsulado substituindo farelo de soja nas dietas. Em conclusão, o produto nitrato encapsulado não mostrou riscos de desenvolvimento da metahemoglobinemia até a dosagem de 3% e pode ser utilizado como fonte de nitrogênio em dietas para terminação de bovinos. O nitrato encapsulado é seguro e aplicável na alimentação de ruminantes.

Aimed to evaluate the growing inclusion of encapsulated nitrate (ENP) as non-protein nitrogen source in place of soybean meal on digestibility variables, performance, nitrate waste and nitrite in meat, feeding behavior variables, methemoglobin and blood constituents of feedlot finished steers. One hundred and twenty steers uncastrated (339.5 ± 28.3 kg) were divided into groups of 6 animals, housed in 20 pens and distributed in a randomized block design with 5 blocks and 4 treatments: control (CTL) - bran Soy; ENP-1-1 ENP% (0.65% NO3-) in the diet MS; ENP-2-2 ENP% (1.30% NO3); ENP ENP-3-3% (1.95% NO3-). The diets were composed with respect 90:10 concentrate: forage (sugarcane bagasse). The experiment lasted 84 days. The dry matter intake decreased linearly (9.6 to 8.4 kg / day; P <0.05) with the addition of increasing amounts of encapsulated nitrate in the diet of steers. However, carcass yield and fat thickness were not influenced (P> 0.05) by treatments. There was quadratic trend (0.121, 0.130, 0.128, 0.127, respectively; P = 0.07) to gain in housing. The nitrate concentration in the flesh increased linearly (3.48, 2.73, 3.98, 6.59 mg NO3- / kg of fresh meat, P = 0.02) with the addition PNS, although nitrite (NO2-) It was not detected. There was a tendency for the quadratic reduction (P = 0.07) per unit time of intake of dry matter and a quadratic reduction (P <0.01) when expressed on the basis of NDF rumination. Quadratic effect in chewing were observed per unit of dry matter intake (P = 0.03) and NDF intake (P <0.01). The blood concentration of methemoglobin increased linearly (P <0.05) increased with the addition of nitrate encapsulated product, but did not reach values that characterize risk of poisoning. For blood variables (creatinine, alkaline phosphatase, total protein, albumin, and glucose) had no effect (P> 0.05) for treatments. However, there was a quadratic effect (P <0.01) for triglycerides in the blood, and a linear increase for total cholesterol (P = 0.05), urea variables (P <0.01), aspartate aminotransferase (P <0 01) and gamma-glutamyl transferase (P = 0.04) resulted in a decreasing linear effect. The apparent digestibility of nutrients had quadratic effect for all nutrients with rising levels of nitrate encapsulated replacing soybean meal in diets. In conclusion, the encapsulated nitrate product showed no development of methemoglobinemia risks to the doses of 3% and can be used as a nitrogen source in the diets for finishing cattle. The encapsulated nitrate is safe and applicable in ruminant feed.

Atividade antioxidante in vitro de extrato de folhas de oliveira (Olea europaea L.) e seu efeito protetor sobre danos oxidativos em eritrócitos humanos Pirassununga

O objetivo do presente estudo foi avaliar a atividade antioxidante de extrato de folhas de oliveira (EFO) (Olea europaea L.) por diferentes metodologias analíticas in vitro e in situ, para verificação de efeito em sistemas biológicos. O extrato foi obtido a partir de folhas secas de oliveira, previamente micronizadas, em metanol/água (80/20%) na proporção 1:20 (m/v), após remoção de compostos solúveis em n-hexano. Após liofilização, no EFO foi avaliado o poder redutor por Folin-Ciocalteau, conteúdo de flavonoides totais, teor de oleuropeina, poder de redução do íon férrico (FRAP) e atividade antioxidante sobre DPPH, ABTS+, ânion superóxido (O2), ácido hipocloroso (HOCl) e óxido nítrico (NO). O extrato foi também avaliado quanto ao efeito protetor sobre danos oxidativos em eritrócitos humanos. O ácido ascórbico foi utilizado como referência. O experimento foi repetido seis vezes (n = 6) e os ensaios realizados em duplicata. O poder redutor do extrato e o conteúdo de flavonoides totais e oleuropeína foram 131,7 ± 9,4 mg equivalente de ácido gálico/g extrato seco (ms), 19,4 ± 1,3 mg equivalente de quercetina/g ms e 25,5 ± 5,2 mg oleuropeína/g ms, respectivamente. O ensaio de FRAP apresentou 281,8 ± 22,8 mg equivalente de trolox/g ms. O EFO foi efetivo na inibição dos radicais DPPH e ABTS+, dependente da concentração de extrato, com valores de IC50 de 13,8 ± 0,8 e 16,1 ± 1,2 g/mL, respectivamente. Com relação à atividade antioxidante sobre espécies reativas de importância biológica, o EFO apresentou forte capacidade de inibição de O2 (IC50 = 52,6 ± 2,1 g/mL) e NO (IC50 = 48,4 ± 6,8 g/mL), quando comparado ao ácido ascórbico. Porém, a inibição de HOCl não foi tão eficiente (IC50 = 714,1 ± 31,4 g/mL). O EFO inibiu a hemólise induzida em eritrócitos de maneira dependente da concentração (IC50 = 7,8 ± 1,1 g/mL), assim como a peroxidação lipídica e a formação de meta-hemoglobina, com valores de IC50 de 38,0 ± 11,7 e 186,3 ± 29,7 g/mL, respectivamente. Os resultados obtidos neste estudo sugerem que extrato de folhas de oliveira possui efetiva atividade antioxidante em sistemas biológicos, pelo efeito sequestrador de determinadas espécies reativas que participam dos processos bioquímicos, e pela prevenção de danos oxidativos em eritrócitos humanos. Portanto, sua ingestão pode estar relacionada com a prevenção de estresse oxidativo in vivo, com consequentes benefícios à saúde.

The aim of this study was to evaluate the antioxidant activity of olive leaf extract (OLE) (Olea europaea L.) by different in vitro and in situ analytical methodologies for determination of its effect in biological systems. The extract was obtained from dried olive leaves, previously micronized, in methanol/water (80/20%) in ratio 1:20 (w/v), after removal of n-hexane soluble compounds. After lyophilization, OLE was analyzed for reducing power by Folin-Ciocalteau, total flavonoid content, oleuropein content, ferric reducing antioxidant power (FRAP) and antioxidant activity against DPPH, ABTS+, superoxide anion (O2), hypochlorous acid (HOCl), and nitric oxide (NO). The extract was also analyzed against oxidative damage in human erythrocytes. Ascorbic acid was used as reference. The experiment was repeated six times (n = 6) and the assays were performed in duplicate. The reducing power and total flavonoid and oleuropein contents of extract were 131.7 ± 9.4 mg galic acid equivalent/g dry extract (dw), 19.4 ± 1.3 mg quercetin equivalent/g dw, and 25.5 ± 5.2 mg oleuropein/g dw, respectively. The FRAP assay was 281.8 ± 22.8 mg trolox equivalent/g dw. The OLE was effective in inhibition of DPPH and ABTS+ radicals, in a concentration dependent manner, with IC50 values of 13.8 ± 0.8 and 16.1 ± 1.2 g/mL, respectively. In relation to the antioxidant activity against reactive species of biological importance, the OLE showed high ability to inhibit O2 (IC50 = 52.6 ± 2.1 g/mL) and NO (IC50 = 48.4 ± 6.8 g/mL), when compared to ascorbic acid. However, inhibition of HOCl was not as efficient (IC50 = 714.1 ± 31.4 g/mL). The OLE inhibited induced erythrocyte hemolysis in a concentration dependent manner (IC50 = 7.8 ± 1.1 g/mL) as well as lipid peroxidation and the formation of methemoglobin, with IC50 values of 38.0 ± 11.7 and 186.3 ± 29.7 g/mL, respectively. The results suggest that olive leaf extract has effective antioxidant activity in biological systems, based on its scavenging effect of certain reactive species that participate in biochemical processes, and the prevention of oxidative damage in human erythrocytes. So, the intake of olive leaf extract may be related to the prevention of in vivo oxidative stress, with health benefits.

Desempenho, parâmetros bioquímicos e hematológicos de juvenis de jundiá (Rhamdia quelen), expostos a diferentes níveis de nitrito e cálcio na água

Os objetivos neste trabalho foram determinar o efeito de diferentes níveis de nitrito (NO2-) associado ao cálcio (Ca2+) na água sobre o desempenho, parâmetros bioquímicos e hematológicos em juvenis de jundiá (Rhamdia quelen). Cento e sessenta animais foram estocados em 16 caixas (n=10) de 40 litros com aeração constante e mantidos em um sistema de recirculação de água com filtro U.V durante 60 dias. O delineamento utilizado foi o inteiramente casualizado com 4 tratamentos e 4 repetições em esquema fatorial com 2 níveis de NO2- (0,05 e 1,4 mg L-1) x 2 níveis de Ca2+ na água (5 e 20 mg L-1). Os peixes (8,9±0,2 g e 15,0±0,8 cm) foram alimentados com ração extrusada (32% PB e máx. 2,0 % de Ca2+) duas vezes ao dia à vontade. Diariamente foi feito a retirada dos resíduos por sifonagem, e 80% da água foi substituída por outra com níveis de nitrito e cálcio previamente ajustados. Os níveis de nitrito e cálcio foram mantidos por meio da adição de nitrito de sódio (NaNO2) e carbonato de cálcio (CaCO3), respectivamente. Foram avaliados: o desempenho zootécnico, os parâmetros bioquímicos e hematológicos para juvenis de jundiá (Rhamdia quelen). A sobrevivencia final não foi afetada pelos níveis de nitrito associado ao Ca2+. Aos 30 dias, observou-se que não houve alterações (P>0,05) no ganho de peso, biomassa, taxa de crescimento específico e conversão alimentar entre os tratamentos analisados. Aos 60 dias, observou-se aumento (P<0,05) no ganho de peso, biomassa e taxa de crescimento específico para os animais do tratamento controle em relação ao tratamento alto NO2- e Ca2+ baixo, e para o tratamento baixo NO2- e Ca2+ alto em relação ao tratamento alto NO2- e Ca2+ alto. Ao final do período experimental, observou-se que o consumo de ração foi maior no tratamento baixo NO2- e Ca2+ alto em relação ao tratamento alto NO2- e Ca2+ alto. Não houve alterações (P>0,05) para a converção alimentar ao final dos 60 dias experimentais. Não houve alterações (P>0,05) nos níveis de lactato e glicogênio no fígado. Os animais do tratamento controle apresentaram níveis (P<0,05) mais elevados de proteína no fígado em relação aos peixes submetidos a alto NO2- e Ca2+ baixo. Os níveis de glicose no fígado dos peixes foram maiores (P<0,05) no tratamento controle em relação aos tratamentos baixo NO2- e Ca2+ alto e alto NO2- e Ca2+ baixo. Os níveis de lactato e glicogênio no músculo apresentaram-se menor (P<0,05) no tratamento controle em relação ao tratamento alto NO2- e Ca2+ baixo. O nível de proteína no músculo foi menor (P<0,05) no tratamento alto NO2- e Ca2+ alto em relação ao tratamento baixo NO2- e Ca2+ alto e ao tratamento alto NO2- e Ca2+ baixo. Os níveis de glicose no músculo apresentaram-se maior (P<0,05) no tratamento controle em relação ao tratamento alto NO2- e Ca2+ baixo, e maior (P<0,05) no tratamento baixo NO2- e Ca2+ alto em relação ao tratamento alto NO2- e Ca2+ alto. O aumento da dureza não favoreceu os animais submetidos a elevados níveis de nitrito em relação ao níveis de hemoglobina. Os peixes expostos a alto NO2- e Ca2+ alto, apresentaram uma redução neste parâmetro em relação ao tratamento baixo NO2- e Ca2+ alto (T2). Tal resultado pode ser um indicativo de que houve oxidação da hemoglobina do sangue em metahemoglobina, causando intoxicação nos peixes. Sendo assim, a utilização de 20 mg L-1Ca2+ na água não apresenta efeito positivo na redução da toxidez do nitrito em relação ao desempenho, parâmetros bioquímicos e hematológicos para juvenis de jundiá (Rhamdia quelen).

The objectives of this study were to determine the effect of different levels of nitrite (NO2-) associated with calcium (Ca2+) in the water on the performance, biochemical and hematological parameters of jundiá (Rhamdia quelen). One hundred and sixty animals were stored in 16 boxes (n = 10) of 40 liters with constant aeration and kept in a water recirculation system with UV filter for 60 days. The design was completely randomized with 4 treatments and 4 replications in a factorial design with two levels of NO2- (0,05 e 1,4mg L-1) x 2 levels of Ca2+ in water (5 e 20 mg L-1). Fish (8.9±0.2 g and 15.0±0.8 cm) were fed with the diet (32% CP and max. 2.0% Ca2+) twice a day at home. Was done daily removal of waste by siphoning, and 80% of the water was replaced by another with nitrite and calcium levels previously set. The nitrite and calcium levels were maintained by the addition of sodium nitrite (NaNO2) and calcium carbonate (CaCO3), respectively. They evaluated: the growth performance, biochemical and hematological parameters for juvenile catfish (Rhamdia quelen). The final survival was not affected by nitrite levels associated with Ca2+. At 30 days, it was observed that there was no change (P>0.05) in weight gain, biomass, specific growth rate and feed conversion between the analyzed treatments. At 60 days, there was an increase (P<0.05) in weight gain, biomass and specific growth rate for animals of the control treatment in relation to the treatment high NO2- and Ca2+ down, and for treatment low NO2- and Ca2+ high in relation to the treatment high NO2- and Ca2+ high. At the end of the experiment, it was found that the feed intake was higher of the treatment low NO2- and Ca2+ high in relation to the treatment high NO2- and Ca2+ high. No change (P>0.05) for converting food to end the 60-day trial. No change (P>0.05) in the levels of lactate and glycogen in the liver. The treatment showed control levels (P<0.05) higher protein in the liver compared to fish subjected to high Ca2+ and NO2- low. Glucose levels in fish liver were higher (P<0.05) in the control treatment in relation to the treatments low NO2- and Ca2+ high and high NO2- and Ca2+ down. The levels of lactate and glycogen in muscle showed a lower (P<0.05) in the control treatment in relation to the treatment high NO2- and Ca2+ down. The protein level in the muscle was lower (P<0.05) in treatment high NO2- and Ca2+ high in relation to treatment low NO2- and Ca2+ high and treatment high NO2- and Ca2+ down. Glucose levels in the muscle had a higher (P<0.05) of the control treatment in relation to the treatment high NO2- and Ca2+ low, and higher of the treatment low NO2- and Ca2+ high in relation to the treatment high NO2- and Ca2+ high. The increase in hardness does not favored animals subjected to high levels of nitrite in relation to the hemoglobin levels. Fish exposed to high NO2- and Ca2+ high, showed a reduction in this parameter for the processing low NO2- and Ca2+ high (T2). This result may be an indication that there was blood hemoglobin oxidation in methemoglobin, causing poisoning in fish. Thus, the use of 20 mg L- 1Ca2+ in water has no positive effect in reducing the toxicity of nitrite in relation toperformance, biochemical and hematological parameters for juvenile catfishes (Rhamdia quelen).

Comparison between biochemical responses of the teleost pacu and its hybrid Tambacu (Piaractus mesopotamicus xColossoma macropomum) to short term nitrite exposure

Aquatic environmental factors are very changeable in short periods. Among these factors are pH, temperature, dissolved oxygen, ammonia and ions. Nitrite, as one ion naturally present in aquatic systems, deserves particular consideration as it is highly toxic for many species. Among fish, nitrite may have harmful effects, such as methemoglobin (MtHb) formation, disruption to the gill and hepatic structure, which could result in hemolytic anemia and cell hypoxia by reducing the functional hemoglobin content. In this work, we compared hematological and metabolical responses of pacu and its hybrid tambacu exposed to 20 ppm of environmental nitrite. It was observed that the MtHb content was less than 18% in tambacu while pacu reached nearly 8%. These data reflect specific differences in nitrite uptake by the gill. The hematocrit of both fish was distinct; pacu did not have a typical response of poisoning by nitrite. This fact shows less skill of the hybrid to cope with environmental nitrite. Incipient hemolytic anemia was observed in pacu and both species presented a neoglycogenic profile. The glucose-provider character of the liver was more evident in tambacu. The white muscle of both species presented distinct metabolic behavior. While in pacu the white muscle was predominantly oxidative, in tambaqui the lactic fermentation was the most important metabolic profile. Metabolic and hematological observations in both species show that they present distinct metabolical strategies to cope with toxic effects of nitrite and there is no evidence that the hybrid is more resistant to nitrite.

Os fatores ambientais nos meios aquáticos são muito flutuantes em curtos intervalos de tempo. Valores de pH, temperatura, oxigênio dissolvido, amônia e íons podem estar freqüentemente variando. Entre esses íons, o nitrito merece especial atenção por ser altamente tóxico para muitas espécies. Entre os peixes, o nitrito pode apresentar efeitos danosos como a formação de metahemoglobina (MtHB), lesão às estruturas branquiais e hepática, podendo levar a quadros de anemia hemolítica e hipóxia celular pela redução do teor de hemoglobina funcional. Neste trabalho, foram comparadas as respostas hematológicas e metabólicas do pacu e de seu híbrido tambacu expostos a 20 ppm de nitrito ambiental, e verificou-se que o teor de MtHb no tambacu foi menor que 18%, enquanto no pacu atingiu valores de 8%. Esses valores refletem diferenças específicas na captação de nitrito pelas brânquias. O hematócrito de ambas as espécies foi diferente; o pacu não apresentou uma resposta típica à intoxicação pelo nitrito. Este fato revelou uma diminuição na capacidade do híbrido em resistir ao nitrito ambiental. Observou-se no pacu um princípio de anemia hemolítica. As duas espécies mostraram um perfil bioquímico neoglicogênico. O papel glicemiante do fígado foi mais evidente no tambacu. O músculo branco de ambas as espécies mostrou um comportamento metabólico distinto. Enquanto o músculo do pacu foi predominantemente oxidativo, o músculo branco do tambaqui exposto ao nitrito realizou fermentação láctica. As observações metabólicas e hematológicas em ambas as espécies indicam que estas apresentam estratégias metabólicas diferentes para enfrentar os efeitos tóxicos do nitrito ambiental, não sendo evidenciada qualquer vantagem do híbrido neste particular.

Functional behavior of tortoise hemoglobin Geochelone denticulata

The hemolysate from Geochelone denticulata contains two main hemoglobin components, as shown by ion exchange chromatography and polyacrylamide gel electrophoresis (PAGE). Electrophoresis under dissociating conditions showed three types of globin chains. The apparent molecular mass, as determined by gel filtration on Sephadex G-200, was compatible with tetrameric Hb, which was unable to polymerize. The G. denticulata Hb has a P50 value of 9.56 mm Hg at pH 7.4. The Hb oxygenation appears to be under the control of organic phosphates and hydrogen ion since it is strongly affected by those species. In the presence ATP or IHP the P50 values increased to 29.51 mm Hg and 54.95 mm Hg, respectively, at pH 7.4. The n50 was generally lower than 1.5 in stripped Hb, suggesting a dissociation of tetramers. In the presence of organic phosphates n50 values increased to approximately 2.5. The Bohr effect was evident in oxygen equilibrium experiments. The hematocrit (32%) and Hb concentration (5.7 mM as heme) of G. denticulata blood were substantially larger than those of G. carbonaria, but the methemoglobin levels were similar in both species, approximately 1%. Thus, the oxygen capacity of blood appears to be higher in G. denticulata than in G. carbonaria, particularly considering the functional properties of their Hbs, which would guarantee the survival of animals.

O hemolisado de Geochelone denticulata contém dois componentes principais, de acordo com a cromatografia de troca iônica e PAGE. Eletroforese sob condições dissociantes mostrou 3 tipos de cadeias de globina. A massa molecular aparente, determinada pela filtração em gel sobre Sephadex G-200, foi compatível com Hb tetramérica que foi incapaz de polimerizar. A Hb de G. denticulata tem valor de P50 de 9,56 mm Hg em pH 7,4. A oxigenação da Hb parece estar sob controle de fosfatos orgânicos e íons hidrogênio, uma vez que ela é fortemente afetada por essas espécies. Na presença de ATP ou IHP, os valores de P50 aumentaram para 29,51 mm Hg e 54,95 mm Hg, respectivamente, a pH 7,4. O n50 foi geralmente menor que 1,5 na Hb stripped, sugerindo dissociação de tetrâmeros. Na presença de fosfatos orgânicos, os valores de n50 aumentaram para aproximadamente 2,5. O efeito Bohr foi evidente nos experimentos de equilíbrio com oxigênio. O hematócrito de 32% e a concentração de Hb de 5,7 mM em heme no sangue de G. denticulata foram substancialmente maiores do que da G. carbonaria, mas os níveis de metahemoglobina foram similares em ambas as espécies, aproximadamente 1%. Portanto, a capacidade de oxigenação do sangue parece ser maior na G. denticulata, particularmente considerando as propriedades funcionais da Hb, que garantiria a sobrevivência dos animais.

Functional behavior of tortoise hemoglobin Geochelone denticulata

The hemolysate from Geochelone denticulata contains two main hemoglobin components, as shown by ion exchange chromatography and polyacrylamide gel electrophoresis (PAGE). Electrophoresis under dissociating conditions showed three types of globin chains. The apparent molecular mass, as determined by gel filtration on Sephadex G-200, was compatible with tetrameric Hb, which was unable to polymerize. The G. denticulata Hb has a P50 value of 9.56 mm Hg at pH 7.4. The Hb oxygenation appears to be under the control of organic phosphates and hydrogen ion since it is strongly affected by those species. In the presence ATP or IHP the P50 values increased to 29.51 mm Hg and 54.95 mm Hg, respectively, at pH 7.4. The n50 was generally lower than 1.5 in stripped Hb, suggesting a dissociation of tetramers. In the presence of organic phosphates n50 values increased to approximately 2.5. The Bohr effect was evident in oxygen equilibrium experiments. The hematocrit (32%) and Hb concentration (5.7 mM as heme) of G. denticulata blood were substantially larger than those of G. carbonaria, but the methemoglobin levels were similar in both species, approximately 1%. Thus, the oxygen capacity of blood appears to be higher in G. denticulata than in G. carbonaria, particularly considering the functional properties of their Hbs, which would guarantee the survival of animals.

O hemolisado de Geochelone denticulata contém dois componentes principais, de acordo com a cromatografia de troca iônica e PAGE. Eletroforese sob condições dissociantes mostrou 3 tipos de cadeias de globina. A massa molecular aparente, determinada pela filtração em gel sobre Sephadex G-200, foi compatível com Hb tetramérica que foi incapaz de polimerizar. A Hb de G. denticulata tem valor de P50 de 9,56 mm Hg em pH 7,4. A oxigenação da Hb parece estar sob controle de fosfatos orgânicos e íons hidrogênio, uma vez que ela é fortemente afetada por essas espécies. Na presença de ATP ou IHP, os valores de P50 aumentaram para 29,51 mm Hg e 54,95 mm Hg, respectivamente, a pH 7,4. O n50 foi geralmente menor que 1,5 na Hb stripped, sugerindo dissociação de tetrâmeros. Na presença de fosfatos orgânicos, os valores de n50 aumentaram para aproximadamente 2,5. O efeito Bohr foi evidente nos experimentos de equilíbrio com oxigênio. O hematócrito de 32% e a concentração de Hb de 5,7 mM em heme no sangue de G. denticulata foram substancialmente maiores do que da G. carbonaria, mas os níveis de metahemoglobina foram similares em ambas as espécies, aproximadamente 1%. Portanto, a capacidade de oxigenação do sangue parece ser maior na G. denticulata, particularmente considerando as propriedades funcionais da Hb, que garantiria a sobrevivência dos animais.

Eritrograma glutationa reduzida e superóxido dismutase eritrocitários e metahemoglobina em equinos da raça Árabe submetidos a exercício em esteira : efeito da suplementação com vitamina E (dl-alfa-tocoferol)

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The objective of this study was to evaluate the oxidative erythrocyte metabolism in equines submitted to exercise on high-speed treadmill and the effect of vitamin E supplementation. Eight adults Arabian horses, males and females, were divided: control group (CG) and group supplemented with vitamin E (EG), (1000 UI/animal/day). All the equines were submitted to exercise with two incremental tests (T1 and T2). Exercise protocol for two tests started with 1.8m/s for 5 min, 4m/s for 3 min, 6m/s for 2 min and right after, periods of 1 min, challenging the equines with increasing speeds until the animals had no condition to keep the exercise on a treadmill inclined at 7%. Between the tests, a training protocol was performed for 20 days. Blood samples were taken before, during, and until 120 hours after exercise to determine erytrogram, erythrocyte reduced glutathione (GSH), superoxide dismutase (SOD), methemoglobin, erythrocyte osmotic fragility (EOF), total plasmatic protein (TPP), seric malondialdehyde (MDA) and vitamin E, seric enzymatic activity of aspartate aminotransferase (AST) and creatine kinase (CK), blood lactate and bloodgas. The results were compared by non-parametric Mann-Whitney and Friedman tests. Although differences were detected in only a few variables, it was possible to see increase in erytrogram and TPP by spleenic contraction and/or decrease of the plasma volume, and increase the erythrocyte volume by swelling. Sport anemia was observed between 24h and 120h after the exercise. The methemoglobin was compatible with the physiological levels and the EOF increased during the exercise in both groups. The MDA elevation confirm the liperoxidation by exercise effect, less intense EG by the supplementation with vitamin E. The exercise also induced increase of AST and CK enzymes, increase of blood lactate and metabolic acidosis