Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 29
Filtrar
Mais filtros










Base de dados
Intervalo de ano de publicação
1.
Biomed Pharmacother ; 149: 112883, 2022 May.
Artigo em Inglês | MEDLINE | ID: mdl-35692123

RESUMO

Euphorbia lathyris seeds have been used to treat various medical conditions. We previously reported that ethanolic extract from the defatted seed of Euphorbia lathyris (EE) (variety S3201) possesses a potent in vitro antitumor activity against colon cancer (CRC) cell lines. However, the effects of EE on CRC in vivo models and its possible preventive activity have not been elucidated. The aim of this study is to develop an in vivo study to corroborate its efficacy. For this purpose, two tumor induction models have been developed. In orthotopic xenograft model, it has been shown that EE reduces tumor size without hematological toxicity. The ethanolic extract induced an intense apoptosis in tumors mediated by caspase 3. Using the Azoxymethane/Dextran Sulfate Sodium model, a reduction of dysplastic polyps has been demonstrated, showing its preventive power. Furthermore, EE promoted the presence of an eubiotic microbiotal environment in the mucosa of the colon and induced an increase in antioxidant enzyme activity. This fact was accompanied by a modulation of cytokine expression that could be related to its protective mechanism. Therefore, although further experiments will be necessary to determine its applicability in the treatment of CRC, ES could be a new prevention strategy as well as treatment for this type of tumor, being a powerful candidate for future clinical trials.


Assuntos
Neoplasias do Colo , Euphorbia , Azoximetano/toxicidade , Neoplasias do Colo/tratamento farmacológico , Sulfato de Dextrana , Etanol , Humanos , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico
2.
Calcif Tissue Int ; 98(6): 609-18, 2016 06.
Artigo em Inglês | MEDLINE | ID: mdl-26801156

RESUMO

Stanozonol (ST) is a synthetic derivative of testosterone; it has anabolic/androgenic activity, increasing both the turnover of trabecular bone and the endocortical apposition of bone. The present study aimed to examine the effects of ST on bone status in rats by bone mineral content, markers of formation and resorption, bone density, and structural and microarchitectural parameters. Twenty male Wistar rats were randomly distributed into two experimental groups corresponding to placebo or ST administration, which consisted of weekly intramuscular injections of 10 mg/kg body weight of ST. Plasma parameters were analyzed by immunoassay. Bone mineral content was determined by spectrophotometry. Bone mineral density (BMD) and structural parameters were measured by peripheral quantitative computed tomography, and trabecular and cortical microarchitecture by micro-computed tomography. Plasma Ca, Mg, and alkaline phosphatase were higher, and urinary Ca excretion, corticosterone, and testosterone concentrations lower in the ST group. Femur Ca content was higher and P content was lower in the ST, whereas osteocalcin, aminoterminal propeptides of type I procollagen, and C-terminal telopeptides of type I collagen were lower. Total cross-sectional, trabecular, and cortical/subcortical areas were lower in the ST. No differences were observed on BMD and area parameters of the diaphysis as well as on trabecular and cortical microarchitecture. The use of ST increases bone mineralization, ash percentage, and Ca and Mg content in femur. In spite of an absence of changes in BMD, geometric metaphyseal changes were observed. We conclude that ST alters bone geometry, leads to low bone turnover, and thus may impair bone quality.


Assuntos
Anabolizantes/toxicidade , Remodelação Óssea/efeitos dos fármacos , Calcificação Fisiológica/efeitos dos fármacos , Estanozolol/toxicidade , Animais , Densidade Óssea/efeitos dos fármacos , Fêmur/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Microtomografia por Raio-X
3.
Int J Sports Med ; 36(12): 984-91, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26252547

RESUMO

We analyzed the effects of high-intensity exercise (HIE) and anabolic androgenic steroids (AAS) on brain redox status. 40 male Wistar rats were randomly distributed in 4 experimental groups (n=10) with or without HIE and with or without weekly Stanozolol administration. Thiobarbituric acid-reactive substances (TBARs) and protein carbonyl content (PCC) were assessed. Total superoxide dismutase (tSOD), manganese superoxide dismutase (Mn-SOD), copper/zinc superoxide dismutase (CuZn-SOD) and catalase (CAT) activities were measured. Finally, protein expression levels of glutathione peroxidase (GPx), NAD(P)H dehydrogenase, Quinone 1 (NQO1), NF-E2-Related Factor 2 (Nrf2), glial fibrillary acidic protein (GFAP), nuclear factor kappa ß p65 (NF-κß) and signal transducer and activator of transcription 3 were determined. Brain PCC concentrations were lower in the HIE groups compared to the untrained controls, whereas CAT activity was higher (both, p<0.01). Both HIE and AAS groups exhibited higher expression levels of GFAP and GPx, but lower NQO1 levels (all, p<0.05). There were increased expression levels of NF-κß in the AAS groups (p<0.01). In addition, there was increased expression of Nrf2 in the HIE groups (p<0.001). HIE*AAS interactions were found on TBARs content and GFAP expression, with HIE downregulating and upregulating AAS-mediated increases in TBARs and GFAP, respectively (p<0.05). Overall, HIE appeared to reduce the AAS-mediated negative effect on brain redox status.


Assuntos
Anabolizantes/farmacologia , Encéfalo/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Condicionamento Físico Animal/métodos , Estanozolol/farmacologia , Animais , Biomarcadores/metabolismo , Peso Corporal , Encéfalo/anatomia & histologia , Encéfalo/enzimologia , Ingestão de Alimentos , Masculino , Tamanho do Órgão , Carbonilação Proteica , Distribuição Aleatória , Ratos Wistar , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
4.
J Physiol Pharmacol ; 66(2): 181-90, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25903949

RESUMO

Crosstalk may occur between cannabinoids and other systems controlling appetite, since cannabinoid receptors are present in hypothalamic circuits involved in feeding regulation, and likely to interact with orexin. In this study, an immunohistochemical approach was used to examine the effect of the intracerebroventricular administration of cannabinoid receptor inverse agonist AM 251 on orexin neuropeptide in the hypothalamic system. AM-activated neurons were identified using c-Fos as a marker of neuronal activity. The results obtained show that AM 251 decreases orexin A immunoreactivity, and that it increases c-Fos-immunoreactive neurons within the hypothalamus when compared with the vehicle-injected control group. We also studied the effects of subchronic intraperitoneal administration of AM 251 on food intake, body weight, and protein utilization. The administration of AM 251 at 1, 2, or 5 mg/kg led to a significant reduction in food intake, along with a significant decrease in the digestive utilization of protein in the groups injected with 1 and 2 mg/kg. There was a dose-related slowdown in weight gain, especially at the doses of 2 and 5 mg/kg, during the initial days of the trial. The absence of this effect in the pair-fed group reveals that any impairment to digestibility was the result of administering AM 251. These data support our conclusion that hypothalamic orexigenic neuropeptides are involved in the reduction of appetite and mediated by the cannabinoid receptor inverse agonist. Furthermore, the subchronic administration of AM 251, in addition to its effect on food intake, has significant effects on the digestive utilization of protein.


Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Canabinoides/metabolismo , Ingestão de Alimentos/efeitos dos fármacos , Região Hipotalâmica Lateral/efeitos dos fármacos , Orexinas/metabolismo , Proteínas/metabolismo , Receptores de Canabinoides/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Região Hipotalâmica Lateral/metabolismo , Injeções Intraperitoneais/métodos , Masculino , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Piperidinas/farmacologia , Proteínas Proto-Oncogênicas c-fos/metabolismo , Pirazóis/farmacologia , Ratos , Ratos Wistar
5.
Int J Sports Med ; 35(8): 639-44, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24424961

RESUMO

We investigated the renal effects of a high-intensity exercise (HIE) program based on strength training. 20 Wistar rats were randomly assigned to 2 experimental groups performing HIE or control over 12 weeks. Urinary volume, pH, citrate and calcium, and plasma urea, total proteins, creatinine, albumin, lactate dehydrogenase, creatine kinase (CK), calcium, magnesium, corticosterone and testosterone were measured. We also studied renal morphology with the Fibrosis HR(®) software. Plasma urea and CK concentrations were higher in the HIE compared to the control group (p < 0.05), whereas plasma creatinine was lower (p < 0.01). Plasma corticosterone was higher (p < 0.05) and testosterone lower (p < 0.01) in the HIE group. Except for the higher urinary volume found in the HIE group (p < 0.05), no differences between groups were observed in the rest of urinary parameters analyzed. Renal interstitial connective tissue was ~30% higher in the HIE group (p < 0.05). Glomerular tufts and mesangial areas were also higher in the HIE group (all, p < 0.05). No differences between groups were observed in the glomerular area. Overall, HIE promoted a worse morphological renal profile that might be associated with a higher risk for incidence of kidney disease in the long-term. The stress induced by the type of exercise performed could be on the basis of this worse morphological renal status.


Assuntos
Rim/anatomia & histologia , Rim/metabolismo , Condicionamento Físico Animal , Treinamento Resistido , Animais , Biomarcadores/sangue , Biomarcadores/urina , Peso Corporal , Corticosterona/sangue , Creatina Quinase/urina , Ingestão de Alimentos , Masculino , Músculo Esquelético/metabolismo , Nitrogênio/metabolismo , Tamanho do Órgão , Distribuição Aleatória , Ratos Wistar , Estresse Fisiológico , Testosterona/sangue , Ureia/sangue
6.
Nutr Hosp ; 28(1): 127-36, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23808440

RESUMO

INTRODUCTION: Dietary protein amount and source, hypertrophy resistance training (RT) and anabolicandrogenic steroids (AAS) may affect body weight and plasma and hepatic lipid profile. MATERIAL AND METHODS: 157 adult male Wistar rats were randomly distributed in 16 experimental groups resulting in: normal-protein (NP) or high-protein (HP) diets, whey or soy-protein diets, with or without RT and with or without AAS, for 3 months. RESULTS AND DISCUSSION: Final body weight was lower in the RT and AAS groups compared to sedentary and non- AAS groups, respectively (all, p<0.001). Plasma total cholesterol (TC) was lower for the HP compared to the NP diets, for the whey compared to the soy-protein diets and for the AAS compared to the non-AAS groups (all, p<0.001). Plasma HDL-cholesterol was higher in the RT groups (p<0.05) but lower for the AAS groups (p<0.001), the HP and the soy-protein diets (p<0.05). Plasma triglycerides (TAG) were lower for the HP diet (p<0.001), for the RT (p=0.002) and the non-AAS groups (p=0.001). Liver TC was lower for the NP (p<0.01), for the soyprotein (p<0.05) and for the AAS groups (p<0.001). Liver TAG were lower for the whey-protein diet (p<0.001), RT and non-AAS groups (both, p<0.05). Some interactions were found, such as the greater effect of AAS on reducing body weight of rats that performed RT or ingested a HP diet (all, p<0.05). HDL-cholesterol was higher when RT was combined with HP diets (p=0.010) or non-AAS and when HP diets were combined with non-AAS (both,p<0.001). Groups that combined RT with non-AAS administration obtained the lowest hepatic TAG (p<0.05). CONCLUSION: Among all the interventions tested, AAS was the factor that most negatively affected plasma and hepatic lipid profile, whereas HP diets and RT could benefit lipid profile, especially when combined.


Introducción: La cantidad y la fuente de proteína, el entrenamiento de fuerza hipertrofia (EF) y los esteroides anabolizantes androgénicos (EAA) pueden alterar el peso corporal y el perfil lipídico plasmático y hepático. Material y métodos: 157 ratas Wistar adultas macho se distribuyeron al azar en 16 grupos experimentales del siguiente modo: dietas normoproteica (NP) o hiperproteicas (HP), proteínas de lactosuero o de soja, con y sin EF y con o sin EAA, durante un periodo experimental de 3 meses. Resultados y discusión: El peso corporal final fue menor en los grupos con EF y EAA en comparación con los grupo sedentario y sin EAA, respectivamente (todos, p<0,001). El colesterol plasmático total (CT) fue menor en el grupo con dieta HP en comparación con las dieta NP, para las dietas de proteínas de lactosuero en comparación con las proteínas de soja, y para el grupo con EAA en comparación con el grupo sin EAA (todos, p<0,001). Las concentraciones plasmáticas de colesterol HDL fueron superiores en los grupos de EF (p<0,05) y menores en los grupos con EAA (p<0,001), y de dieta HP o con proteína de soja (p<0,05). Los triglicéridos (TAG) plasmáticos fueron menores con la dieta HP (p<0,001), el EF (p=0,002) y la no administración de EAA (p=0,001). El CT hepático fue menor en los grupos de dieta NP (p<0,01), dieta con proteínas de soja (p<0,05) y grupo de EAA (p<0,001). Los TAG hepáticos fueron menores en los grupos de dieta de proteínas de lactosuero (p<0,001), EF y sin EAA (ambos, p<0,05). Se hallaron algunas interacciones como un mayor efecto de los EAA en la reducción del peso corporal de las ratas que realizaron EF o ingirieron una dieta HP (todos, p<0,05). Las concentraciones plasmáticas de colesterol HDL fueron superiores cuando se combinó el EF con las dietas HP (p=0,010) o sin EAA y cuando las dietas HP se combinaron con el no uso de EAA (ambos, p<0,001). Finalmente, los grupos que combinaron el EF sin EAA obtuvieron los valores más bajos de TAG hepáticos (p<0,05). Conclusión: De entre todas las intervenciones testadas, los EAA fueron el factor que más negativamente afectó al perfil lipídico plasmático y hepático, mientras que las dietas HP y el EF podrían beneficiar, en general, el perfil lipídico, especialmente cuando se combinan.


Assuntos
Anabolizantes/farmacologia , Androgênios/farmacologia , Peso Corporal/efeitos dos fármacos , Peso Corporal/fisiologia , Proteínas Alimentares/farmacologia , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/fisiologia , Treinamento Resistido , Esteroides/farmacologia , Animais , Dieta , Ingestão de Alimentos/fisiologia , Hipertrofia , Lipídeos/sangue , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Nitrogênio/análise , Nitrogênio/metabolismo , Ratos , Ratos Wistar
7.
Nutr Hosp ; 28(1): 232-7, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23808456

RESUMO

INTRODUCTION: High-protein (HP) diets might affect renal status. We aimed to examine the effects of a HP diet on plasma, urinary and morphological renal parameters in rats. MATERIAL AND METHODS: Twenty Wistar rats were randomly distributed in 2 experimental groups with HP or normal-protein (NP) diets over 12 weeks. RESULTS AND DISCUSSION: Final body weight was a 10%lower in the HP group (p < 0.05) whereas we have not observed differences on food intake, carcass weight and muscle ashes content. No significant clear differences were observed on plasma parameters, whereas urinary citrate was an 88% lower in the HP group (p = 0.001) and urinary pH a 15% more acidic (p < 0.001). Kidney wet mass was ~22 heavier in the HP group (p < 0.001). Renal mesangium area was a 32% higher in the HP group (p < 0.01). Glomerular 1 and 2 were also ~30 higher in the HP diet (p < 0.01 and p < 0.05, respectively) and glomerular area a 13% higher (p < 0.01). CONCLUSION: High-protein diet promoted a worse renal profile, especially on urinary and morphological markers, which could increase the risk for developing renal diseases in the long time.


Introducción: Las dietas hiperproteicas (HP) pueden afectar la función renal. El objetivo del presente estudio fue examinar los efectos de una dieta HP sobre parámetros renales plasmáticos, urinarios y morfológicos en ratas. Material y métodos: Veinte ratas Wistar fueron distribuidas aleatoriamente en 2 grupos experimentales con dieta HP o normoproteicas durante 12 semanas. Resultados y discusión: El peso corporal final fue un 10% inferior en el grupo de dieta HP (p < 0,05) mientras que no se han observado diferencias en la ingesta de comida, peso de la carcasa del animal y el contenido muscular de cenizas. No se observaron claras diferencias en los parámetros plasmáticos, mientras que el citrato urinario fue de un 88% inferior en el grupo de dieta HP (p = 0,001) y el pH urinario un 15% más ácido (p < 0,001). El peso del riñón en sustancia fresca fue un 22% más pesado en el grupo de dieta HP (p < 0,001). El área mesangial fue un 32% mayor en el grupo HP (p < 0,01). El floculo glomerular 1 y 2 fueron también ~ 30 mayores en la dieta HP (p < 0,01 y p < 0,05, respectivamente) y el área glomerular un 13% mayor (p <0,01). Conclusión: Una dieta hiperproteica promueve un peor perfil renal, especialmente en los marcadores urinarios y morfológico, que podrían aumentar el riesgo de desarrollar enfermedades renales a largo plazo.


Assuntos
Proteínas Alimentares/farmacologia , Rim/fisiologia , Animais , Composição Corporal , Peso Corporal/fisiologia , Citratos/urina , Dieta , Ingestão de Alimentos/fisiologia , Taxa de Filtração Glomerular , Rim/patologia , Testes de Função Renal , Masculino , Tamanho do Órgão/efeitos dos fármacos , Ratos , Ratos Wistar
8.
Nutr Hosp ; 26(6): 1478-86, 2011.
Artigo em Espanhol | MEDLINE | ID: mdl-22411399

RESUMO

INTRODUCTION: High protein (HP) diet consumption may adversely affect metabolic acidosis and hepatic and renal health. Despite such potentially adverse effect, there are only few studies analyzing the effects of resistance training on the parameters that could be altered by such diets. MATERIAL AND METHODS: A total of 32 adult male Wistar rats were randomly distributed in 4 experimental groups (n = 8): normoprotein or HP diets, with or without resistance training. Diets were based on a whey protein hydrolyzate, and the experimental period lasted for 90 days. RESULTS AND DISCUSSION: Consumption of HP diets and resistance training significantly affected food intake, body composition and plasmatic levels of total cholesterol and triglycerides. Consumption of HP diets led to a considerable increase in liver and kidney weight (P < 0.001), urinary volume and acidity, as well as in the urinary excretion of Ca, with a parallel reduction in the urinary excretion of citrate (P < 0.05). The buffering action of resistance training on such diet-induced alterations was especially evident in the levels of hepatic and plasma triglycerides, plasmatic urea, and in liver and kidney weight (P < 0.001). CONCLUSION: Resistance training had a protective action against alterations of hepatic and renal health status and some metabolic parameters like hepatic and plasma triglycerides.


Assuntos
Acidose/etiologia , Acidose/prevenção & controle , Proteínas Alimentares/efeitos adversos , Nefropatias/epidemiologia , Nefropatias/prevenção & controle , Hepatopatias/etiologia , Hepatopatias/prevenção & controle , Condicionamento Físico Animal/fisiologia , Animais , Cálcio/urina , Colesterol/sangue , Citratos/urina , Ingestão de Alimentos , Hipertrofia , Masculino , Proteínas do Leite , Tamanho do Órgão , Ratos , Ratos Wistar , Triglicerídeos/sangue , Ureia/sangue , Proteínas do Soro do Leite
9.
Biochem J ; 359(Pt 3): 687-95, 2001 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-11672444

RESUMO

Selenium-dependent glutathione peroxidase-1 (GPX1) protects against reactive-oxygen-species (ROS)-induced oxidative stress in vivo, but its role in coping with reactive nitrogen species (RNS) is unclear. Our objective was to compare the protection of GPX1 against cytotoxicity of superoxide generator diquat (DQ), NO donor S-nitroso-N-acetyl-penicillamine (SNAP) and peroxynitrite generator 3-morpholinosydnonimine (SIN-1). Primary hepatocytes were isolated from GPX1-knockout (KO) and wild-type (WT) mice and cultured in complete Williams's medium E with various levels of these agents alone or in combination for up to 12 h. While the KO cells were more susceptible to cell death, DNA fragmentation and protein carbonyl formation induced by 0.25-1 mM DQ, these cells were as tolerant as the WT cells to cytotoxicity of 0.1-1 mM SNAP or 0.5-2 mM SIN-1. Treating cells with SNAP (0.1 or 0.25 mM) in addition to DQ produced synergistic cytotoxicity that minimized differences in apoptotic cell death and oxidative injuries between the KO and WT cells. Less protein nitrotyrosine was induced by 0.05-0.5 mM DQ+0.25 mM SNAP in the KO than in the WT cells. Total GPX activity in the WT cells was reduced by 65 and 25% by 0.5 mM DQ+0.1 mM SNAP and 0.5 mM DQ, respectively. Decreases in Cu,Zn-superoxide dismutase (SOD) activity and increases in Mn-SOD activity in response to DQ or DQ+SNAP were greater in the KO cells than in the WT cells. In conclusion, GPX1 was more effective in protecting hepatocytes against oxidative injuries mediated by ROS alone than by ROS and RNS together. Knockout of GPX1 did not enhance cell susceptibility to RNS-associated cytotoxicity. Instead, it attenuated protein nitration induced by DQ+SNAP.


Assuntos
Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Hepatócitos/metabolismo , Molsidomina/análogos & derivados , Nitrogênio/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo , Animais , Sobrevivência Celular , Células Cultivadas , Fragmentação do DNA , Diquat/farmacologia , Interações Medicamentosas , Hepatócitos/efeitos dos fármacos , Herbicidas/farmacologia , Camundongos , Camundongos Knockout , Molsidomina/farmacologia , Doadores de Óxido Nítrico/farmacologia , Nitrogênio/química , S-Nitroso-N-Acetilpenicilamina/farmacologia , Superóxido Dismutase/metabolismo , Glutationa Peroxidase GPX1
10.
Free Radic Biol Med ; 27(5-6): 605-11, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10490281

RESUMO

Two experiments were conducted to determine the protection and the underlying mechanisms of cellular glutathione peroxidase (GPX1) against lethal, acute oxidative stress induced by an intraperitoneal injection of 24 mg diquat/kg body weight. In experiment 1, mortality and survival times were compared among selenium (Se)-adequate or deficient GPX1 knockout mice [GPX1(-/-)] and wild-type mice (WT). In experiment 2, mice from these four groups were euthanized at 0, 1, 2, and 3 h after the injection of diquat to elucidate the time course of oxidative events. The stress produced 100% mortality in all of the groups except for the Se-adequate WT, which were euthanized on day 7 for analysis. The Se-deficient WT and the Se-adequate GPX1(-/-) had similar survival times (4.1 and 3.9 h), which were longer (p < .05) than that of the Se-deficient GPX1(-/-) (2.4 h). However, these three GPX1-deficient groups had higher levels (p < .05) of hepatic F2-isoprostanes and carbonyl contents and/or plasma alanine aminotransferase activities than those of the Se-adequate WT. The diquat-induced formations of hepatic F2-isoprostanes in these animals peaked at 1 h and preceded the rise of plasma alanine aminotransferase in the Se-adequate GPX1(-/-). Responses of hepatic superoxide dismutase activities to the diquat treatment were affected by the GPX1 level. In conclusion, GPX1 is the major selenoprotein to protect mice against the lethal oxidative stress induced by diquat.


Assuntos
Diquat/farmacologia , Glutationa Peroxidase/genética , Estresse Oxidativo/genética , Alanina Transaminase/sangue , Animais , Catalase/metabolismo , Fígado/efeitos dos fármacos , Fígado/enzimologia , Camundongos , Camundongos Knockout , Prostaglandinas/metabolismo , Proteínas/metabolismo , Selênio/deficiência , Selenoproteínas , Superóxido Dismutase/metabolismo , Fatores de Tempo
11.
FASEB J ; 13(11): 1467-75, 1999 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-10428770

RESUMO

Since our prior work indicated that Se-dependent cellular glutathione peroxidase (GPX1) was necessary for protection against paraquat lethality, the present studies were to elucidate the biochemical mechanisms related to that protection. Four groups of mice [Se-deficient or -adequate GPX1 knockout and wild-type (WT)] were injected (i.p.) with 50 mg paraquat/kg body weight and tissues were collected 0, 0.5, 1, 2, 3, or 4 h after the injection. Whereas the ratios of NADPH/NADP and NADH/NAD in lung were reduced by 50-70% only 0.5 h after the injection in all groups, these two ratios in liver of the Se-adequate WT were significantly higher than those of the three GPX1 knockout or deficient groups 2-4 h after the injection. The paraquat-induced pulmonary lipid peroxidation and hepatic protein oxidation, measured as F(2)-isoprostanes and carbonyl contents, respectively, peaked at 1 h in these three groups. No such oxidative events were shown in any tissue of the Se-adequate WT throughout the time course. Whereas the F(2)-isoprostane formation was accelerated by both GPX1 knockout and Se deficiency in liver, it was not significantly elevated by the paraquat treatment in brain of any group. The paraquat injection also resulted in temporal changes in lung GPX activity and GPX1 protein in the Se-adequate WT, and significant reductions in lung total SOD activity in the GPX1 knockout or deficient groups. In conclusion, GPX1 plays a critical role in maintaining the redox status of mice under acute oxidative stress, and protects against paraquat-induced oxidative destruction of lipids and protein in vivo. These protections of GPX1 seem to be inducible and coordinated with those of other antioxidant enzymes.


Assuntos
Glutationa Peroxidase/fisiologia , Peroxidação de Lipídeos , NADP/metabolismo , NAD/metabolismo , Proteínas/metabolismo , Animais , Herbicidas/toxicidade , Camundongos , Camundongos Knockout , Oxirredução , Estresse Oxidativo , Paraquat/toxicidade
12.
Proc Soc Exp Biol Med ; 221(1): 80-6, 1999 May.
Artigo em Inglês | MEDLINE | ID: mdl-10320635

RESUMO

High iron consumption has been proposed to relate to an increase in the risk of colon cancer, whereas high levels of supplemental sodium phytate effectively reduce iron-induced oxidative injury and reverse iron-dependent augmentation of colorectal tumorigenesis. However, the protective role of intrinsic dietary phytate has not been determined. In this study, we examined the impact of removing phytate present in a corn-soy diet by supplemental microbial phytase on susceptibility of pigs to the oxidative stress caused by a moderately high dietary iron intake. Thirty-two weanling pigs were fed the corn-soy diets containing two levels of iron (as ferrous sulfate, 80 or 750 mg/kg diet) and microbial phytase (as Natuphos, BASF, Mt. Olive, NJ, 0 or 1200 units/kg). Pigs fed the phytase-supplemented diets did not receive any inorganic phosphorus to ensure adequate degradation of phytate. After 4 months of feeding, liver, colon, and colon mucosal scrapings were collected from four pigs in each of the four dietary groups. Colonic lipid peroxidation, measured as thiobarbituric acid reacting substances (TBARS), was increased by both the high iron (P< 0.0008) and phytase (P< 0.04) supplementation. Both TBARS and F2-isoprostanes, an in vivo marker of lipid peroxidation, in colonic mucosa were affected by dietary levels of iron (P< 0.03). Mean hepatic TBARS in pigs fed the phytase-supplemented, high iron diet was 43%-65% higher than that of other groups although the differences were nonsignificant. Moderately high dietary iron induced hepatic glutathione peroxidase activity (P= 0.06) and protein expression, but decreased catalase (P< 0.05) in the colonic mucosa. In conclusion, intrinsic phytate in corn and soy was protective against lipid peroxidation in the colon associated with a moderately high level of dietary iron.


Assuntos
Colo/efeitos dos fármacos , Colo/metabolismo , Ferro da Dieta/toxicidade , Peroxidação de Lipídeos/efeitos dos fármacos , Ácido Fítico/administração & dosagem , Animais , Antioxidantes/metabolismo , Dieta , Feminino , Mucosa Intestinal/efeitos dos fármacos , Mucosa Intestinal/metabolismo , Ferro da Dieta/administração & dosagem , Fígado/efeitos dos fármacos , Fígado/metabolismo , Masculino , Estresse Oxidativo , Suínos , Substâncias Reativas com Ácido Tiobarbitúrico/metabolismo
13.
Arch Biochem Biophys ; 365(2): 262-7, 1999 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-10328821

RESUMO

Proteolysis of two purified recombinant enzymes, namely, the Aspergillus niger phytase (r-PhyA) and the Escherichia coli pH 2.5 acid phosphatase (r-AppA), by pepsin and trypsin was investigated in this study. After r-PhyA and r-AppA were incubated with different concentrations of pepsin or trypsin, their residual phytase activities and amounts of inorganic phosphorus released from soybean meal were determined. Both enzymes retained more than 85% of their original activities at the trypsin/phytase ratios (w/w) 0.001 and 0. 005, while r-AppA and r-PhyA lost 60 and 20% of the original activity at the ratio of 0.01 or 0.025, respectively. In contrast, there was a 30% increase in phytase activity after r-AppA was incubated with pepsin at the ratios of 0.005 or 0.01. Meanwhile, r-PhyA lost 58 to 77% of its original activity under the same conditions. Trypsin and pepsin affected the hydrolysis of phytate phosphorus from soybean meal by r-AppA and r-PhyA in a similar way to their residual phytase activities. All of these in vitro proteolyses were confirmed by SDS-PAGE analysis. Our results demonstrate different sensitivities of r-AppA and r-PhyA to trypsin and pepsin, suggesting active trypsin resistant r-PhyA and pepsin resistant r-AppA polypeptides.


Assuntos
6-Fitase/metabolismo , Fosfatase Ácida/metabolismo , Aspergillus niger/enzimologia , Escherichia coli/enzimologia , Pepsina A/metabolismo , Tripsina/metabolismo , 6-Fitase/genética , Fosfatase Ácida/genética , Aspergillus niger/genética , Escherichia coli/genética , Concentração de Íons de Hidrogênio , Cinética , Fragmentos de Peptídeos/isolamento & purificação , Fragmentos de Peptídeos/metabolismo , Proteínas Recombinantes/metabolismo
14.
Arch Dermatol ; 113(7): 983, 1977 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-879823
17.
Am J Clin Pathol ; 64(4): 452-63, 1975 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-1199970

RESUMO

The results obtained with eight pregnancy kits on 735 urines were compared. Overall accuracies were similar and fairly high (93.4 to 95.37%), although only 78.28% of all pregnancies were simultaneously detected by all eight kits. It is suggested that the different performances of each kit could be accounted for not only by lack of product homologation, differences in kit sensitivity, and laboratorian error, but also by the presence of various hormonal components in various concentrations in the urines of pregnant women, and by the presence of different antibodies against these hormonal components in various concentrations in the antisera included in the various kits.


Assuntos
Testes Imunológicos de Gravidez/normas , Clorpromazina/farmacologia , Gonadotropina Coriônica/urina , Estudos de Avaliação como Assunto , Reações Falso-Negativas , Reações Falso-Positivas , Feminino , Haloperidol/farmacologia , Humanos , Metadona/farmacologia , Gravidez , Proteinúria , Psicotrópicos/farmacologia , Tioridazina/farmacologia
18.
Am J Med Technol ; 41(8): 288-98, 1975 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-1155487

RESUMO

The applicability, reliability and accuracy of various carbohydrate media in the determination of fermentation reactions of 16 Pasteurella and Actinobacillus isolates were investigated. Laboratory prepared and commercially prepared carbohydrate media were inoculated with known test organisms and results were compared with those obtained at the Center for Disease Control (CDC). Only two of the 15 media tested reproduced more than 90 per cent of the reactions obtained at CDC. Significant differences in performance were noted depending on source and type of dehydrated media, manufacturer, type of carbohydrate and isolate studied. Considerations for media selection are summarized.


Assuntos
Actinobacillus/metabolismo , Metabolismo dos Carboidratos , Meios de Cultura , Fermentação , Pasteurella/metabolismo , Meios de Cultura/normas , Estudos de Avaliação como Assunto , Controle de Qualidade
19.
Artigo em Inglês | MEDLINE | ID: mdl-805172

RESUMO

Bioautography following electrophoresis on agar gel, a technique for the characterization of antibiotics, is described in detail and its possible uses and advantages discussed. Eleven antibiotics of the beta-lactamic group were characterized. Penicillin G and Penicillin V showed two components with anti-microbial activity. Attempts were made to identify the components by an adaptation of the technique and the results are discussed.


Assuntos
Antibacterianos , Ampicilina , Bioensaio , Cefaloridina , Cefalosporinas , Cefalotina , Eletroforese em Gel de Ágar , Meticilina , Filtros Microporos , Penicilina G , Penicilina V/análogos & derivados , Procaína
20.
Clin Orthop Relat Res ; (106): 245-7, 1975.
Artigo em Inglês | MEDLINE | ID: mdl-1126082

RESUMO

This is a case report of a contamination of an injured knee with an unusual organism, Vibrio parahaemolyticus, that is likely to occur in patients living in coastal areas but often overlooked. The infection apppears to be sensitive to a number of antibiotics and very likely cured, whether recognized or not as the proper organism.


Assuntos
Traumatismos do Joelho/complicações , Vibrioses/microbiologia , Vibrio/isolamento & purificação , Infecção dos Ferimentos/microbiologia , Criança , Meios de Cultura , Humanos , Masculino , Vibrioses/etiologia , Microbiologia da Água , Infecção dos Ferimentos/etiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...