Administration with L-glutamine and L-glutathione protects the nitrergic innervation of the penile tissue of diabetic rats

Erectile dysfunction is caused due to neuropathy, resulting from a high oxidative stress, in this way treatment with antioxidants may be promising. Aim of this work was toinvestigate the effects of the administration of 2% L-glutamine and 1% L-glutathione on the penile tissue of diabetic rats analyzing the nerve fibers that expressing Nitric Oxide Synthase Neuronal (nNOS). Forty-eight male Wistar rats distributed into six groups were used: normoglycemic, diabetic, normoglycemic administered with 2% L-glutamine, normoglycemic administered with 1% L-glutathione, diabetic administered with 2% L-glutamine, and diabetic administered with 1% L-glutathione. After a 120 days experimental period, the animals were euthanized, and the penile tissues were collected and processed for the subsequent immunohistochemical procedure (nNOS) and posterior varicosities morphometry analysis. Diabetic rats administered with L-glutamine and with L-glutathione displayed larger varicosity areas of 14 and 15% compared to the diabetic group (p < 0.05). On the other hand, the administration of 2% L-glutamine and 1% L-glutathione in normoglycemic animals promoted a reduction of 3.3% and 2.4% compared to the normoglycemic group (p < 0.05). We concluded that both L-glutamine and L-glutathione administrations exerted a protective effect on the penile nitrergic innervation of diabetic rats, which can have a positive impact on the erectile function and thattheir use in normoglycemic animals should be better investigated.(AU)

Sexual motivation and performance in sexual naïve and experienced rats treated with ivermectin: an ultrasonic vocalization study / Motivação e desempenho sexual em ratos com e sem experiência sexual tratados com ivermectina: um estudo da vocalização ultrassônica

In mammals, ivermectin acts as a GABAA receptor agonist and stimulates GABA release. Previous studies showed that ivermectin (IVM) reduces sexual performance, impairing the latency to the first mount and intromission. These parameters are usually considered motivational parameters of sexual behavior. However, IVM increases GABAergic activity leading to motor incoordination. Thus, it is reasonable to propose that IVM affects sexual performance via motor incoordination pathways. The present study analyzed ultrasonic vocalization in rats to verify whether IVM impairs sexual behavior via motivational mechanisms or motor impairment. Because sexual experience attenuates the impairment of motor performance, rats with sexual experience were also studied. Sexually naive and experienced rats were administered a therapeutic IVM dose and saline. The rats were exposed to receptive females, and the latency to the first mount was evaluated, followed by the 50-kHz USV test. IVM treatment in naïve rats increased the latency to first to mount relative to Saline naïve rats, while no differences were observed between saline and experienced rats. In naïve-IVM rats, a reduced frequency and total calls and increased mean time of calls occur relative to SAL-naïve rats. Experienced IVM rats did not show differences in the frequency, mean, and maximal calls close to Saline experienced rats. However, an increase in the total calls and the dominant frequency of calls were observed in IVM-experienced rats compared to Saline experienced rats. A negative and positive correlation occurred between the latency to the first mount and USVs in groups with and without ivermectin exposure. Hence, we propose that ivermectin increased the sexual motivation of rats exposed to a female in estrous based in USVs despite an increased latency to the first mount that occurred. The increased latency to the first mount resulted from motor incoordination, as previously observed and proposed by our group.(AU)

Em mamíferos, a ivermectina (IVM) atua como agonista do receptor GABAA e estimula a liberação de GABA. Estudos anteriores mostraram que a IVM reduz o desempenho sexual, prejudicando a latência para a primeira monta e intromissão. Esses parâmetros são geralmente considerados parâmetros motivacionais do comportamento sexual. Por outro lado, a IVM aumenta a atividade GABAérgica levando à incoordenação motora. Assim, é possível que a IVM afete o desempenho sexual devido a um impedimento motor. O presente estudo analisou a vocalização ultrassônica em ratos para verificar se a IVM prejudica o comportamento sexual via mecanismos motivacionais ou comprometimento motor. Uma vez que a experiência sexual atenua o comprometimento do desempenho motor, também foram estudados ratos com experiência sexual. Ratos sexualmente inexperientes e experientes foram administrados com uma dose terapêutica de IVM ou solução salina IVM. Os ratos foram expostos a fêmeas receptivas e foi avaliada a latência para a primeira monta, seguida do teste de vocalização ultrassônica (USV) de 50 kHz. O tratamento com IVM em ratos inexperientes aumentou a latência para a primeira monta em relação a ratos inexperientes tratados com solução salina, enquanto não foram observadas diferenças entre ratos experientes tratados com IVM e solução salina. Em ratos inexperientes tratados com IVM ocorreu redução da frequência e total de USVs, bem como aumento do tempo médio de USVs em relação aos ratos sem experiência. Ratos experientes tratados com IVM não mostraram diferenças na frequência, média e máxima das USVs em relação aos ratos experientes tratados com solução salina; no entanto, observou-se aumento no total de USVs e na frequência dominante de USVS em ratos experientes tratados com IVM comparados aos experientes tratados com solução salina. Observou-se correlação negativa e positiva entre a latência para a primeira monta e USVs nos grupos sem e com experiência tratados com IVM, respectivamente. Assim, propomos que a IVM aumentou a motivação sexual de ratos expostos a uma fêmea em estro com base em USVs, apesar de apresentar aumento na latência para a primeira monta. O aumento da latência para a primeira monta foi atribuída à incoordenação motora, conforme observado anteriormente e proposto por nosso grupo.(AU)

Toxic impacts of a mixture of three pesticides on the reproduction and oxidative stress in male rats

The present study investigated the toxic effect of a mixture of three pesticides (cypermethrin, mancozeb, and metalaxyl) on reproduction and oxidative stress parameters in male Wistar rats. Animals were treated at doses 1/60, 1/30, and 1/10 LD50 of each pesticide daily in the diet for 08 weeks. At the end of the treatment period, animals were sacrificed by decapitation. The results indicate a decrease in the absolute weight of testes and epididymis, the serum of testosterone hormone, and cholesterol levels. These parameters were significant reduced in males exposed to the mixed pesticides. A reduction in sperm concentration, motility, and viability also was observed. Besides, the ingestion of mixed pesticides at all three concentrations caused a significant decrease in GSH, GPx levels and an increase in MDA levels compared to the control group. This was accompanied by histopathological changes in testis and epididymis of rats such as seminiferous tubules degeneration, decreasing number of spermatogenic cells, edema, expansion of interstitial spaces, cell necrosis, and reducing the diameter of the epididymal tube compared to the control group. Thus, we strongly suggest that the mixture of pesticides causes damages to the male reproductive system.(AU)

Determination of basal bone mineral density in the femur bones of male and female Wistar rats.

Changes in bone mineral content of calcium (Ca), phosphorous (P), magnesium and potassium for male and female Wistar rats during their development from 3 weeks old to adulthood (27 weeks old) were measured. Bone mineral content was related to areal bone mineral density (BMD) which was measured in vivo at the femoral neck using a calibrated X-ray transmission system to obtain basal curves as a function of the age of the specimen. Diagnostic curves were built to determine low BMD (osteopaenia) and osteoporosis in female rats fed a Ca-depleted diet (50%) based on the obtained data and the criteria established by the World Health Organization. Bone mineral content is directly related to sex and age, but P did not change throughout the experimental period. P content did not exhibit significant changes with growing, while Ca was greatest in male rats, producing significant differences in the Ca:P ratio. Male rats reach the Ca:P ratio peak before female rats. However, areal BMD does not follow the same trend. On the other hand, osteoporosis produced a 45% decrease in this parameter for young and mature adults. These results make Z-score values available to diagnose bone-mass losses and hence the possibility of improving the conditions of non-contact measurement of BMD in vivo. This technique can be used for future experiments with Wistar rats.

Spirulina ameliorates arsenic induced reproductive toxicity in male rats

Spirulina (Spirulina platensis), has numerous health benefits including antioxidant, immunomodulatory, and anti-inflammatory activities, works against heavy metal toxicity, and is often used as a food supplement in human, animals, birds and fishes. This study aimed to evaluate the protective ability of the dietary spirulina against the toxic effects of inorganic arsenic (iAs) on male reproductive parameters in rats. Seventy-two mature Long-Evans male rats, dividing into six groups (T0, T1, T2, T3, T4 and T5) (12 rats/group) were included in this study. The T3, T4 and T5 group rats were treated with three consecutive doses (1.0 g, 1.5 g and 2.0 g/kg feed) of spirulina in feed along with 3.0 mg NaAsO2/kg body weight (BW) in drinking water (DW) daily for 90 days. Each rat of group T1 received NaAsO2 (3.0 mg/kg BW) in DW, and those of T2 group were fed with spirulina (2.0 g/kg feed) daily for 90 days. The rats of group T0 served as the control with normal feed and water. Total arsenic (tAs) contents, reproductive parameters (testicular weight, sperm motility and morphology), and histological changes in the testicles were evaluated in these rats. Arsenic dosing significantly (p=0.003, Kruskal-Wallis test) increased the tAs contents in the testicles, decreased testes weight, sperm morphology and motility compared to the controls. The effect of arsenic dosing was also evidenced by the histological changes like decreased germinal layers in the seminiferous tubules of the treated rats. Moreover, dietary spirulina (2.0 g/kg feed) supplementation significantly (p=0.011, Kruskal-Wallis test) lowered tAs contents in testicles and increases testes weights, sperm motility and morphology. Therefore, spirulina can be used as an effective dietary supplement to ameliorate the adverse effects of arsenic induced reproductive toxicities. However, further study is required to elucidate the underlying molecular mechanisms of reduction of arsenic induced reproductive toxicity by spirulina.(AU)

Divergent projections of the prelimbic cortex bidirectionally regulate active avoidance.

The prefrontal cortex (PFC) integrates incoming information to guide our actions. When motivation for food-seeking competes with avoidance of danger, the PFC likely plays a role in selecting the optimal choice. In platform-mediated active avoidance, rats avoid a tone-signaled footshock by stepping onto a nearby platform, delaying access to sucrose pellets. This avoidance requires prelimbic (PL) PFC, basolateral amygdala (BLA), and ventral striatum (VS). We previously showed that inhibitory tone responses of PL neurons correlate with avoidability of shock (Diehl et al., 2018). Here, we optogenetically modulated PL terminals in VS and BLA to identify PL outputs regulating avoidance. Photoactivating PL-VS projections reduced avoidance, whereas photoactivating PL-BLA projections increased avoidance. Moreover, photosilencing PL-BLA or BLA-VS projections reduced avoidance, suggesting that VS receives opposing inputs from PL and BLA. Bidirectional modulation of avoidance by PL projections to VS and BLA enables the animal to make appropriate decisions when faced with competing drives.

Combination of ketamine and xylazine with opioids and acepromazine in rats: Physiological changes and their analgesic effect analysed by ultrasonic vocalization.

In this study, the effect of four anaesthetic protocols that included the combination of xylazine (X) and ketamine (K) with acepromazine (A) and opioids (methadone (Me), morphine (Mo) or tramadol (T)) was evaluated in laboratory rats of both sexes. Ultrasonic vocalization (USV) was used as an indicator of pain during the recovery period. The objective was to evaluate the physiological parameters and the analgesic effect of each protocol to determine which protocol was the safest and fulfil the requirements of a balanced anaesthesia. The better protocols were the XKA protocol for both sexes and the XKMe protocol for females because the combinations achieve surgical plane of anaesthesia in rats. However, pain assessment during the formalin test revealed that rats anaesthetized with XKA produced more numbers of USV, suggesting that it is not a good protocol for the control of immediate postoperative pain. All protocols produced depression in body temperature and respiratory and heart rates, and had important effects, such as micturition and maintenance of open eyes. Only rats anaesthetized with XKA protocol did not present piloerection. These results demonstrated that good monitoring and care during anaesthesia must be included to prevent complications that compromise the life of the animal and to ensure a good recovery. The inclusion of analgesia in anaesthesia protocols must be used routinely, ensuring minimal presence of pain and thus more reliable results in the experimental procedures.

Relationship between Body Mass Index (BMI) and testicular and hormonal parameters of sexually active male greater cane rats (Thryonomys swinderianus)

The current upsurge in intensive farming practices of greater cane rat has not only lead to higher growth rate but is accompanied by increased fat deposition especially in the males. This study attempts to characterize one of the most commonly used fat estimation parameter, the body mass index (BMI) as well as evaluates its relationship with testicular and hormonal parameters in seventy-two sexually active male cane rats over a period of one year. Six animals, kidded and raised in a farm, with known ages were used each month. The experimental protocols entail body measurements of weight, height and length; histology; orchidometry; and hormonal immunoassay of testosterone, estradiol, progesterone, LH and FSH using their various kits. The mean values of the body mass (BMI) and Lee (LI) indices of male greater cane rats were 1.18±0.20g/cm2 and 0.30±0.02g/cm respectively with the testicular histology indicating normal spermatogenesis. BMI/LI, both of which followed the same pattern, neither correlate with testicular parameters nor with serum testosterone, progesterone, LH and FSH concentrations but had low correlations with serum estradiol concentration (r2 = 0. 2; p = 0.0023). So, these relationships may provide clue on obesity and its effect on reproductive performance and strengthened the possibility of the characterized BMI/LI as obesity marker for breeding selection in male cane rat.(AU)

Relationship between Body Mass Index (BMI) and testicular and hormonal parameters of sexually active male greater cane rats (Thryonomys swinderianus)

The current upsurge in intensive farming practices of greater cane rat has not only lead to higher growth rate but is accompanied by increased fat deposition especially in the males. This study attempts to characterize one of the most commonly used fat estimation parameter, the body mass index (BMI) as well as evaluates its relationship with testicular and hormonal parameters in seventy-two sexually active male cane rats over a period of one year. Six animals, kidded and raised in a farm, with known ages were used each month. The experimental protocols entail body measurements of weight, height and length; histology; orchidometry; and hormonal immunoassay of testosterone, estradiol, progesterone, LH and FSH using their various kits. The mean values of the body mass (BMI) and Lee (LI) indices of male greater cane rats were 1.18±0.20g/cm2 and 0.30±0.02g/cm respectively with the testicular histology indicating normal spermatogenesis. BMI/LI, both of which followed the same pattern, neither correlate with testicular parameters nor with serum testosterone, progesterone, LH and FSH concentrations but had low correlations with serum estradiol concentration (r2 = 0. 2; p = 0.0023). So, these relationships may provide clue on obesity and its effect on reproductive performance and strengthened the possibility of the characterized BMI/LI as obesity marker for breeding selection in male cane rat.

Análise estatística multivariada da expressão de microRNAs no exercício exaustivo em Rattus norvegicus / Multivariate statistical analysis of expression of microRNAs in the exhaustive exercise in Rattus norvegicus

MicroRNAs são pequenas moléculas de RNA que atuam na regulação e silenciamento gênico em organismos eucariotos. Na atividade física a compreensão da expressão de microRNAs pode ser relevante para entendimento da sua fisiologia. Feito o transcriptoma do exercício exaustivo agudo em Rattus norvegicus, buscou-se analisar a expressão diferencial (através do valor obtido de Fold-Change) de microRNAs, com o auxílio de avaliação estatística multivariada, em ambiente R. Os métodos usados mostraram expressão de 71 miRNAs. Destes, destacaram-se 6 (por análise PCoA) e dois microRNAs: mir145 e mir186 (por análise de expressão diferencial, EBseq). Concluiu-se que com os métodos usados (PCoA, Permanova e Simper) foi possível analisar a expressão diferencial de microRNAs e destacar possíveis alvos de estudo para o exercício experimental extenuante.

MicroRNAs are small molecules of RNA that act on the regulation and gene silencing in eukaryotic organisms. In physical activity the understanding of the expression of microRNAs may be relevant to understanding their physiology. The transcriptome of acute exhaustive exercise in Rattus norvegicus was used to analyze the differential expression (through the Fold-Change value obtained) of microRNAs, with the aid of multivariate statistical evaluation, in the R environment. The methods used showed expression of 71 miRNAs. Of these, six (by PCoA analysis) and two microRNAs: mir145 and mir186 (by differential expression analysis, EBseq) were highlighted. It was concluded that with the methods used (PCoA, Permanova and Simper) it was possible to analyze the differential expression of microRNAs and to highlight possible study targets for the strenuous experimental exercise.

Análise estatística multivariada da expressão de microRNAs no exercício exaustivo em Rattus norvegicus / Multivariate statistical analysis of expression of microRNAs in the exhaustive exercise in Rattus norvegicus

MicroRNAs são pequenas moléculas de RNA que atuam na regulação e silenciamento gênico em organismos eucariotos. Na atividade física a compreensão da expressão de microRNAs pode ser relevante para entendimento da sua fisiologia. Feito o transcriptoma do exercício exaustivo agudo em Rattus norvegicus, buscou-se analisar a expressão diferencial (através do valor obtido de Fold-Change) de microRNAs, com o auxílio de avaliação estatística multivariada, em ambiente R. Os métodos usados mostraram expressão de 71 miRNAs. Destes, destacaram-se 6 (por análise PCoA) e dois microRNAs: mir145 e mir186 (por análise de expressão diferencial, EBseq). Concluiu-se que com os métodos usados (PCoA, Permanova e Simper) foi possível analisar a expressão diferencial de microRNAs e destacar possíveis alvos de estudo para o exercício experimental extenuante.(AU)

MicroRNAs are small molecules of RNA that act on the regulation and gene silencing in eukaryotic organisms. In physical activity the understanding of the expression of microRNAs may be relevant to understanding their physiology. The transcriptome of acute exhaustive exercise in Rattus norvegicus was used to analyze the differential expression (through the Fold-Change value obtained) of microRNAs, with the aid of multivariate statistical evaluation, in the R environment. The methods used showed expression of 71 miRNAs. Of these, six (by PCoA analysis) and two microRNAs: mir145 and mir186 (by differential expression analysis, EBseq) were highlighted. It was concluded that with the methods used (PCoA, Permanova and Simper) it was possible to analyze the differential expression of microRNAs and to highlight possible study targets for the strenuous experimental exercise.(AU)

A lectin of a non-invasive apple snail as an egg defense against predation alters the rat gut morphophysiology.

The eggs of the freshwater Pomacea apple snails develop above the water level, exposed to varied physical and biological stressors. Their high hatching success seems to be linked to their proteins or perivitellins, which surround the developing embryo providing nutrients, sunscreens and varied defenses. The defensive mechanism has been unveiled in P. canaliculata and P. maculata eggs, where their major perivitellins are pigmented, non-digestible and provide a warning coloration while another perivitellin acts as a toxin. In P. scalaris, a species sympatric to the former, the defense strategy seems different, since no toxin was found and the major perivitellin, PsSC, while also colored and non-digestible, is a carbohydrate-binding protein. In this study we examine the structure and function of PsSC by sequencing its subunits, characterizing its carbohydrate binding profile and evaluating its effect on gut cells. Whereas cDNA sequencing and database search showed no lectin domain, glycan array carbohydrate binding profile revealed a strong specificity for glycosphingolipids and ABO group antigens. Moreover, PsSC agglutinated bacteria in a dose-dependent manner. Inspired on the defensive properties of seed lectins we evaluated the effects of PsSC on intestinal cells both in vitro (Caco-2 and IEC-6 cells) and in the gastrointestinal tract of rats. PsSC binds to Caco-2 cell membranes without reducing its viability, while a PsSC-containing diet temporarily induces large epithelium alterations and an increased absorptive surface. Based on these results, we propose that PsSC is involved in embryo defenses by altering the gut morphophysiology of potential predators, a convergent role to plant defensive lectins.

Resveratrol atenua o estresse oxidativo e a lesão muscular de ratos sedentários submetidos ao exercício físico / Resveratrol attenuates oxidative stress and muscle damage in sedentary rats subjected to physical exercise

O sedentarismo é um problema de saúde pública e um dos maiores males da sociedade moderna. Já está bem estabelecido que esforço físico em excesso ou em indivíduos não condicionados acarreta estresse oxidativo e lesões musculares. No presente estudo, foi testada a hipótese de que um único esforço físico é capaz de causar estresse oxidativo e lesão muscular em indivíduos sedentários. Aditivamente foi avaliado efeito antioxidante do polifenol resveratrol (RV) quanto a sua capacidade de atenuar o estresse oxidativo e a lesão muscular causados pelo esforço físico. Para tal, 40 ratos (Rattus norvegicus albinus, Wistar), machos, adultos e sedentários foram aleatoriamente submetidos ou não a 90 minutos de natação, com e sem tratamento com RV (100mg/kg/PV/14dias): N-RV- (n=10) grupo mantido em repouso e não tratado com RV; N-RV+ (n=10) grupo mantido em repouso e tratado com RV; N+RV- (n=10) grupo submetido ao esforço físico de natação e não tratado com RV e N+RV+ (n=10) grupo submetido ao esforço físico de natação e tratado com RV. Em ratos sedentários, o esforço físico da natação promoveu estresse oxidativo (aumento da peroxidação lipídica e diminuição da capacidade antioxidante total do plasma) e aumento significativo da atividade plasmática de creatina quinase (CK) e lactato desidrogenase (LDH). O tratamento com RV diminuiu a peroxidação lipídica e a concentração dos marcadores de lesão muscular (CK e LDH) de ratos sedentários submetidos à natação. Essa é uma das primeiras evidências de que um único esforço físico pode causar estresse oxidativo em indivíduos sedentários e que o RV pode ser uma alternativa para atenuar a lesão muscular causada por esse estresse.(AU)

Physical inactivity is a public health problem when a sedentary population practices physical activity sporadically. Exercise in unconditioned individuals causes oxidative stress and muscle damage. This study tested the hypothesis that a single physical exertion can cause muscle damage and oxidative stress in sedentary individuals, and resveratrol can attenuate it. For this, 40 sedentary adult male rats were equally and randomized into four groups subjected to 90min swimming or rest and administered aqueous resveratrol (100mg/kg/day) or saline for 14 days: N-RV-, rats maintained at rest and administered saline; N-RV+, rats maintained at rest and treated with resveratrol; N+RV-, rats subjected to physical exercise and administered saline; and N+RV+, rats subjected to physical exercise and treated with resveratrol. In sedentary rats, the physical exertion of swimming promoted oxidative stress, i.e. increased lipid peroxidation and decreased plasma total antioxidant capacity, and significant increases in CK and LDH plasma activities. Resveratrol diminished lipid peroxidation and the concentrations of muscle damage markers (CK and LDH) in sedentary rats subjected to swimming. The results provide evidence that a single sudden physical exertion can cause oxidative stress in sedentary rats. Resveratrol showed good results as a treatment for minimizing muscle damage caused by this stress.(AU)

Synergetic effect of chitosan and vitamin C on the oxidative enzyme status in rat exposed to lead acetate / Efeito sinérgico do chitosano e da vitamina C no estado da enzima oxidativa em ratos expostos ao acetato de chumbo

This article discusses the research results on the synergetic effect of chitosan and vitamin C in overcoming free radical effect due to blood lead (Pb2+) accumulation. Blood lead level and enzymatic activities of superoxide dismutase (SOD), catalase oxidase (CAT), and Glutathione peroxidase (GPx) were used as the main parameters. Thirty adult male albino rats were divided into six groups. Group 1 was normal control group; group 2 was the negative control group treated with lead acetate at 175 mg kg-1 body weight (BW). Group 3 was treated with 64 mg kg-1 BW of chitosan day-1. Group 4, 5, and 6 were treated with chitosan and vitamin C combination at the dose of 100, 200, and 300 mg kg-1 BW, respectively. All groups were inducted using 175 mg kg-1 BW of Pb-acetate, excluding control group. Results showed that chitosan and vitamin C treatment at the dose of 300 mg kg-1 BW decreased blood Pb2+ level in rats exposed to Pb-acetate. The combination also significantly increased enzymatic activities from SOD, CAT, and GPx compared to the other groups. In conclusion, the combination of chitosan and vitamin C could elevate the several antioxidative enzymes activities in Pb-acetate induced rats.

Este artigo discute os resultados da pesquisa sobre o efeito sinérgico da quitosana e da vitamina C na superação do efeito dos radicais livres devido ao acúmulo de chumbo no sangue (Pb2+). O nível de chumbo no sangue e as atividades enzimáticas de superóxido dismutase (SOD), catalase oxidase (CAT) e glutationa peroxidase (GPx) foram utilizados como parâmetros principais. Trinta ratos albinos adultos foram divididos em seis grupos. Grupo 1 foi grupo controle normal; o grupo 2 foi o grupo controle negativo tratado com acetato de chumbo a 175 mg kg-1 de peso corporal (PC). O grupo 3 foi tratado com 64 mg kg-1 PC de quitosana dia-1. Os grupos 4, 5 e 6 foram tratados com combinação de quitosana e vitamina C nas doses de 100, 200 e 300 mg kg-1 PC, respectivamente. Todos os grupos foram induzidos usando 175 mg kg-1 de PC de Pb-acetato, excluindo o grupo controle. Os resultados mostraram que o tratamento com quitosana e vitamina C na dose de 300 mg kg-1 PC diminuiu o nível de Pb2+ no sangue em ratos expostos ao acetato de Pb. A combinação também aumentou significativamente as atividades enzimáticas de SOD, CAT e GPx em comparação com os outros grupos. Em conclusão, a combinação de quitosana e vitamina C pode elevar as várias atividades das enzimas antioxidativas em ratos induzidos com acetato de Pb.

Synergetic effect of chitosan and vitamin C on the oxidative enzyme status in rat exposed to lead acetate / Efeito sinérgico do chitosano e da vitamina C no estado da enzima oxidativa em ratos expostos ao acetato de chumbo

This article discusses the research results on the synergetic effect of chitosan and vitamin C in overcoming free radical effect due to blood lead (Pb2+) accumulation. Blood lead level and enzymatic activities of superoxide dismutase (SOD), catalase oxidase (CAT), and Glutathione peroxidase (GPx) were used as the main parameters. Thirty adult male albino rats were divided into six groups. Group 1 was normal control group; group 2 was the negative control group treated with lead acetate at 175 mg kg-1 body weight (BW). Group 3 was treated with 64 mg kg-1 BW of chitosan day-1. Group 4, 5, and 6 were treated with chitosan and vitamin C combination at the dose of 100, 200, and 300 mg kg-1 BW, respectively. All groups were inducted using 175 mg kg-1 BW of Pb-acetate, excluding control group. Results showed that chitosan and vitamin C treatment at the dose of 300 mg kg-1 BW decreased blood Pb2+ level in rats exposed to Pb-acetate. The combination also significantly increased enzymatic activities from SOD, CAT, and GPx compared to the other groups. In conclusion, the combination of chitosan and vitamin C could elevate the several antioxidative enzymes activities in Pb-acetate induced rats.(AU)

Este artigo discute os resultados da pesquisa sobre o efeito sinérgico da quitosana e da vitamina C na superação do efeito dos radicais livres devido ao acúmulo de chumbo no sangue (Pb2+). O nível de chumbo no sangue e as atividades enzimáticas de superóxido dismutase (SOD), catalase oxidase (CAT) e glutationa peroxidase (GPx) foram utilizados como parâmetros principais. Trinta ratos albinos adultos foram divididos em seis grupos. Grupo 1 foi grupo controle normal; o grupo 2 foi o grupo controle negativo tratado com acetato de chumbo a 175 mg kg-1 de peso corporal (PC). O grupo 3 foi tratado com 64 mg kg-1 PC de quitosana dia-1. Os grupos 4, 5 e 6 foram tratados com combinação de quitosana e vitamina C nas doses de 100, 200 e 300 mg kg-1 PC, respectivamente. Todos os grupos foram induzidos usando 175 mg kg-1 de PC de Pb-acetato, excluindo o grupo controle. Os resultados mostraram que o tratamento com quitosana e vitamina C na dose de 300 mg kg-1 PC diminuiu o nível de Pb2+ no sangue em ratos expostos ao acetato de Pb. A combinação também aumentou significativamente as atividades enzimáticas de SOD, CAT e GPx em comparação com os outros grupos. Em conclusão, a combinação de quitosana e vitamina C pode elevar as várias atividades das enzimas antioxidativas em ratos induzidos com acetato de Pb.(AU)

Resveratrol atenua o estresse oxidativo e a lesão muscular de ratos sedentários submetidos ao exercício físico / Resveratrol attenuates oxidative stress and muscle damage in sedentary rats subjected to physical exercise

O sedentarismo é um problema de saúde pública e um dos maiores males da sociedade moderna. Já está bem estabelecido que esforço físico em excesso ou em indivíduos não condicionados acarreta estresse oxidativo e lesões musculares. No presente estudo, foi testada a hipótese de que um único esforço físico é capaz de causar estresse oxidativo e lesão muscular em indivíduos sedentários. Aditivamente foi avaliado efeito antioxidante do polifenol resveratrol (RV) quanto a sua capacidade de atenuar o estresse oxidativo e a lesão muscular causados pelo esforço físico. Para tal, 40 ratos (Rattus norvegicus albinus, Wistar), machos, adultos e sedentários foram aleatoriamente submetidos ou não a 90 minutos de natação, com e sem tratamento com RV (100mg/kg/PV/14dias): N-RV- (n=10) grupo mantido em repouso e não tratado com RV; N-RV+ (n=10) grupo mantido em repouso e tratado com RV; N+RV- (n=10) grupo submetido ao esforço físico de natação e não tratado com RV e N+RV+ (n=10) grupo submetido ao esforço físico de natação e tratado com RV. Em ratos sedentários, o esforço físico da natação promoveu estresse oxidativo (aumento da peroxidação lipídica e diminuição da capacidade antioxidante total do plasma) e aumento significativo da atividade plasmática de creatina quinase (CK) e lactato desidrogenase (LDH). O tratamento com RV diminuiu a peroxidação lipídica e a concentração dos marcadores de lesão muscular (CK e LDH) de ratos sedentários submetidos à natação. Essa é uma das primeiras evidências de que um único esforço físico pode causar estresse oxidativo em indivíduos sedentários e que o RV pode ser uma alternativa para atenuar a lesão muscular causada por esse estresse.(AU)

Physical inactivity is a public health problem when a sedentary population practices physical activity sporadically. Exercise in unconditioned individuals causes oxidative stress and muscle damage. This study tested the hypothesis that a single physical exertion can cause muscle damage and oxidative stress in sedentary individuals, and resveratrol can attenuate it. For this, 40 sedentary adult male rats were equally and randomized into four groups subjected to 90min swimming or rest and administered aqueous resveratrol (100mg/kg/day) or saline for 14 days: N-RV-, rats maintained at rest and administered saline; N-RV+, rats maintained at rest and treated with resveratrol; N+RV-, rats subjected to physical exercise and administered saline; and N+RV+, rats subjected to physical exercise and treated with resveratrol. In sedentary rats, the physical exertion of swimming promoted oxidative stress, i.e. increased lipid peroxidation and decreased plasma total antioxidant capacity, and significant increases in CK and LDH plasma activities. Resveratrol diminished lipid peroxidation and the concentrations of muscle damage markers (CK and LDH) in sedentary rats subjected to swimming. The results provide evidence that a single sudden physical exertion can cause oxidative stress in sedentary rats. Resveratrol showed good results as a treatment for minimizing muscle damage caused by this stress.(AU)

Inside-out and standard vein grafts associated with platelet-rich plasma (PRP) in sciatic nerve repair. A histomorphometric study

Purpose: To evaluated the tubulization technique with standard and inside-out vein, filled or not with platelet-rich plasma (PRP), in sciatic nerve repair. Methods: Seventy male Wistar rats were randomly divided into five groups: IOVNF (Inside-Out Vein with No Filling); IOVPRP (Inside-Out Vein filled with PRP); SVNF (Standard Vein with No Filling); SVPRP (Standard Vein filled with PRP); Sham (Control). The left external jugular vein was used as graft in a 10 mm nervous gap. Results: In the morphological analysis of all groups, myelinated nerve fibers with evident myelin sheath, neoformation of the epineurium and perineurium, organization of intraneural fascicles and blood vessels were observed. In the morphometry of the distal stump fibers, SVPRP group had the highest means regarding fiber diameter (3.63±0.42 m), axon diameter (2.37±0.31 m) and myelin sheath area (11.70±0.84 m2). IOVPRP group had the highest means regarding axon area (4.39±1.16 m2) and myelin sheath thickness (0.80±0.19 m). As for values of the fiber area, IOVNF group shows highest means (15.54±0.67 m2), but are still lower than the values of the Sham group. Conclusion: The graft filled with platelet-rich plasma, with use standard (SVPRP) or inside-out vein (IOVPRP), promoted the improvement in axonal regeneration on sciatic nerve injury.(AU)

Intestinal inflammatory and redox responses to the perioperative administration of teduglutide in rats

Purpose: To investigate the inflammatory and redox responses to teduglutide on an animal model of laparotomy and intestinal anastomosis. Methods: Wistar rats (n=62) were allocated into four groups: Ileal Resection and Anastomosis vs. Laparotomy, each one split into Postoperative Teduglutide Administration vs. No Treatment; and euthanized at the third or the seventh day. Ileal and blood samples were recovered at the baseline and at the euthanasia. Flow cytometry was used to study the inflammatory response (IL-1, MCP-1, TNF-, IFN- and IL-4 levels), oxidative stress (cytosolic peroxides, mitochondrial reactive species, intracellular glutathione and mitochondrial membrane potential) and cellular viability and death (annexin V/propidium iodide double staining). Results: Postoperative teduglutide treatment was associated with higher cellular viability index and lower early apoptosis ratio at the seventh day; higher cytosolic peroxides level at the third day and mitochondrial overgeneration of reactive species at the seventh day; higher tissue concentration of IL-4 and lower local pro-to-anti-inflammatory cytokines ratio at the seventh day. Conclusion: Those findings suggest an intestinal pro-oxidative and anti-inflammatory influence of teduglutide on the peri-operative context with a potential interference in the intestinal anastomotic healing.(AU)

Maternal plasma levels of vascular endothelial growth factor and interleukin-6 in the term-pregnant and non-pregnant rats

Female reproductive functions are associated with changes in the level of systemic cytokines which play pivotal roles during ovulation, development of corpus luteum, embryo implantation, and labor. Although many studies reported elevated level of VEGF during early pregnancy and IL-6 at the onset of labors, there is still incomplete elucidation of the level of these systemic cytokines in the very-late pregnancy or in the non-pregnant states. The purpose of this study was to determine the maternal plasma level of vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) in the term-pregnant and non-pregnant rats to see if their levels are changed at the very end of pregnancy. Blood samples were collected from twelve term-pregnant rats and compared by aged-matched seven non-pregnant rats. Plasma was separated carefully from all samples and the concentrations of VEGF and IL-6 were determined by ELISA techniques. The plasma concentration of VEGF was significantly higher in the non-pregnant rats (0.237 pg/ ml) than in the term-pregnant (0.2 pg/ ml; P < 0.001). The plasma concentration of IL-6 was significantly higher in the term-pregnant rats (50.12 pg/ ml) than in the non-pregnant ones (40.19 pg/ ml; P < 0.05). These findings suggest that the level of VEGF is decreased few days before labor possibly to decrease the ovarian blood flow and to cause luteolysis while the level of IL-6 is increased at the end of pregnancy possibly to cause a local inflammation. Together, these changes are necessary to stimulate the onset of labor.(AU)

Maternal plasma levels of vascular endothelial growth factor and interleukin-6 in the term-pregnant and non-pregnant rats

Female reproductive functions are associated with changes in the level of systemic cytokines which play pivotal roles during ovulation, development of corpus luteum, embryo implantation, and labor. Although many studies reported elevated level of VEGF during early pregnancy and IL-6 at the onset of labors, there is still incomplete elucidation of the level of these systemic cytokines in the very-late pregnancy or in the non-pregnant states. The purpose of this study was to determine the maternal plasma level of vascular endothelial growth factor (VEGF) and interleukin-6 (IL-6) in the term-pregnant and non-pregnant rats to see if their levels are changed at the very end of pregnancy. Blood samples were collected from twelve term-pregnant rats and compared by aged-matched seven non-pregnant rats. Plasma was separated carefully from all samples and the concentrations of VEGF and IL-6 were determined by ELISA techniques. The plasma concentration of VEGF was significantly higher in the non-pregnant rats (0.237 pg/ ml) than in the term-pregnant (0.2 pg/ ml; P < 0.001). The plasma concentration of IL-6 was significantly higher in the term-pregnant rats (50.12 pg/ ml) than in the non-pregnant ones (40.19 pg/ ml; P < 0.05). These findings suggest that the level of VEGF is decreased few days before labor possibly to decrease the ovarian blood flow and to cause luteolysis while the level of IL-6 is increased at the end of pregnancy possibly to cause a local inflammation. Together, these changes are necessary to stimulate the onset of labor.