RESUMO
Post-hatch delayed placement damages the physical and physiological development of broiler chicks. This study was designed to find adequate levels of betaine inclusion in pre-hatching and pre-starter feed, in order to minimize the negative effects of post-hatch delayed placement on broiler chicks. Newly-hatched chicks were allotted in a completely randomized design, with five treatments, five replicates of ten birds each. Five dietetic levels of betaine (control, 0.070, 0.130, 0.200 and 0.260%) were used in the pre-starter ration, offered to the chicks in the transporting box and during the pre-starter phase. Performance, yolk sac retraction, plasma glucose concentration, weight and histomorphometry of the small intestine were evaluated, after 24 hours of feed access and at 7 days of age. A metabolic trial was performed from seven to ten days of age. Betaine supplementation linearly influenced the chicks ileum crypt depth after 24 hours in the transportation box. There was a quadratic effect, with an increase in feed intake up to 0.152% betaine supplementation. There was an improvement in the quality of the jejunum with betaine supplementation above 0.1%. The metabolizable coefficient of the ether extract was improved until reaching 0.163% of betaine supplementation. Betaine supplementation around 0.150% increases feed intake, the use of ether extract and interferes with the intestinal villi of chicks at seven days of age.
Assuntos
Animais , Aves/anatomia & histologia , Betaína/administração & dosagem , Betaína/análise , Glucose/análogos & derivadosRESUMO
Post-hatch delayed placement damages the physical and physiological development of broiler chicks. This study was designed to find adequate levels of betaine inclusion in pre-hatching and pre-starter feed, in order to minimize the negative effects of post-hatch delayed placement on broiler chicks. Newly-hatched chicks were allotted in a completely randomized design, with five treatments, five replicates of ten birds each. Five dietetic levels of betaine (control, 0.070, 0.130, 0.200 and 0.260%) were used in the pre-starter ration, offered to the chicks in the transporting box and during the pre-starter phase. Performance, yolk sac retraction, plasma glucose concentration, weight and histomorphometry of the small intestine were evaluated, after 24 hours of feed access and at 7 days of age. A metabolic trial was performed from seven to ten days of age. Betaine supplementation linearly influenced the chicks ileum crypt depth after 24 hours in the transportation box. There was a quadratic effect, with an increase in feed intake up to 0.152% betaine supplementation. There was an improvement in the quality of the jejunum with betaine supplementation above 0.1%. The metabolizable coefficient of the ether extract was improved until reaching 0.163% of betaine supplementation. Betaine supplementation around 0.150% increases feed intake, the use of ether extract and interferes with the intestinal villi of chicks at seven days of age.(AU)
Assuntos
Animais , Aves/anatomia & histologia , Betaína/administração & dosagem , Betaína/análise , Glucose/análogos & derivadosRESUMO
Aminotransferases (GOT and GPT) activities in the hemolymph of Bradybaena similaris under experimental condition of starvation were studied. At the 10th day of starvation, GOT activity was 416.6% higher than that observed in the fed snails, being reduced and ranging values near to that shown by the control group onwards. GPT activity only varied significantly at the day-30 of starvation. The results were discussed.
Assuntos
Aspartato Aminotransferases/sangue , Hemolinfa/enzimologia , Caramujos/enzimologia , Inanição/metabolismo , Animais , Aspartato Aminotransferases/metabolismo , Análise de RegressãoRESUMO
The inhibition by citrinin (CTN) of lipid peroxidation of mitochondria, sub-mitochondrial particles (SMP) and microsomes was studied. This effect was reversed by the presence of high concentrations of Fe3+ (0.4 and 0.5 mM), suggesting chelation of the mycotoxin with iron or interference in the reduction of Fe3+.
Assuntos
Citrinina/farmacologia , Ferro/farmacologia , Peroxidação de Lipídeos/efeitos dos fármacos , Microssomos Hepáticos/efeitos dos fármacos , Mitocôndrias Hepáticas/efeitos dos fármacos , Animais , Cloretos , Interações Medicamentosas , Feminino , Compostos Férricos/farmacologia , Masculino , Malondialdeído/análise , Ratos , Ratos WistarRESUMO
The effects of citrinin in the maintenance of the homeostasis of the reactive oxygen species in rat liver cells were evaluated. Citrinin (CTN) modifies the antioxidant enzymatic defences of cells through the inhibition of GSSG-reductase and transhydrogenase. No effect was observed on GSH-peroxidase, catalase, glucose 6-phosphate and 6 phosphogluconate dehydrogenases, and superoxide dismutase. The mycotoxin increased the generation of reactive oxygen species, stimulating the production of the superoxide anion in the respiratory chain. The results suggest that oxidative stress is an important mechanism, side by side with other effects previously shown, in the establishment of the cytotoxicity and cellular death provoked by CTN in several tissues.
Assuntos
Antibacterianos/farmacologia , Citrinina/farmacologia , Homeostase/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Animais , Catalase/metabolismo , Relação Dose-Resposta a Droga , Transporte de Elétrons/efeitos dos fármacos , Feminino , Glucosefosfato Desidrogenase/metabolismo , Glutationa Peroxidase/metabolismo , Glutationa Redutase/metabolismo , Masculino , Mitocôndrias/enzimologia , NADP/metabolismo , NADP Trans-Hidrogenases/metabolismo , Fosfogluconato Desidrogenase/metabolismo , Ratos , Ratos Wistar , Superóxido Dismutase/metabolismo , Superóxidos/metabolismoRESUMO
The effects of citrinin on energy production along the respiratory chain and on glycolytic lactate production were examined in BHK-21 cultured cells. Citrinin inhibited the oxygen consumption rate by about 45 per cent. The respiratory rate of digitonin-treated cells energized with succinate, in the presence of ADP, was reduced by about 39 per cent. The mycotoxin inhibited the glucose utilization of BHK-21 cells by about 86 per cent. Cells treated with citrinin produced a small quantity of pyruvate, but were unable to produce lactate. It is concluded that BHK-21 cells cannot generate lactate when oxidative metabolism is inhibited by citrinin. The perturbations in BHK-21 cells caused by citrinin are due to alterations in mitochondrial function and in the glycolytic anaerobic pathway.
Assuntos
Citrinina/farmacologia , Metabolismo Energético/fisiologia , Animais , Linhagem Celular/enzimologia , Respiração Celular/fisiologia , Cricetinae , Glucose/metabolismo , Glicólise/fisiologia , Rim/citologia , Mitocôndrias/enzimologia , Fosforilação OxidativaRESUMO
The effects of the mycotoxin citrinin on renal cortical and liver mitochondrial swelling were studied. Citrinin decreases the rate of swelling induced by the valinomycin-K+ complex, suggesting that the mycotoxin interferes with the mitochondrial membrane fluidity. Citrinin promotes reduction of the amplitude of swelling in the presence of Na+ ions. This alteration reflects interference with complex I of the respiratory chain and ATP synthase complex activity without disarranging the inner mitochondrial membrane, in view of the fact that the shrinkage was not affected. The effect increases with citrinin concentration. Renal tissue is more susceptible than hepatic tissue.
Assuntos
Citrinina/toxicidade , Córtex Renal/ultraestrutura , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Dilatação Mitocondrial/efeitos dos fármacos , Animais , Citrinina/farmacologia , Relação Dose-Resposta a Droga , Córtex Renal/efeitos dos fármacos , Masculino , Ratos , Ratos Wistar , Sódio/farmacologia , Valinomicina/farmacologiaRESUMO
The effect of citrinin on Ca2+ transport was studied in isolated kidney cortex and liver mitochondria, and baby hamster kidney cultured cells. The mycotoxin significantly inhibited the activity of 2-oxoglutarate and pyruvate dehydrogenases in both kidney cortex and liver mitochondria. Citrinin promoted a decrease in the velocity and in the total capacity of Ca2+ uptake, in both mitochondria. Apparently, citrinin acts by a mechanism similar to ruthenium red. In intact cultured cells, citrinin also had a preferential effect on mitochondrial Ca2+ fluxes. Citrinin promoted a marked decrease in the Ca2+ level in the mitochondrial matrix, whereas that of the extramitochondiral fraction became less affected. All the observed effects were dependent on the citrinin concentration.
Assuntos
Cálcio/metabolismo , Citrinina/farmacologia , Mitocôndrias/efeitos dos fármacos , Animais , Transporte Biológico/efeitos dos fármacos , Calcimicina/farmacologia , Carbonil Cianeto p-Trifluormetoxifenil Hidrazona/farmacologia , Linhagem Celular , Cricetinae , Complexo Cetoglutarato Desidrogenase/antagonistas & inibidores , Córtex Renal/efeitos dos fármacos , Córtex Renal/ultraestrutura , Mesocricetus , Mitocôndrias/metabolismo , Mitocôndrias Hepáticas/efeitos dos fármacos , Mitocôndrias Hepáticas/metabolismo , Complexo Piruvato Desidrogenase/antagonistas & inibidores , Ratos , Ratos WistarRESUMO
The cytotoxicity of citrinin was evaluated in an established cell line of baby hamster kidney cells. The primary effect of the mycotoxin was on the adherence of the cells to the culture bottles. Microscopic evaluation of morphological alterations indicated that the cells which were originally elongated and flattened, became swollen and round. Electron microscopic examination showed that citrinin (0.1, 0.5 and 1.0 mM) incubated for 10 hours with cultured cells, promoted drastic alterations of normal mitochondria, with swelling and cell death. Transplasma membrane redox system is inhibited by citrinin (81%). This effect is dependent not only on the toxin concentration, but also on the time of exposure to the cells.
Assuntos
Citrinina/farmacologia , Rim/citologia , Animais , Adesão Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Membrana Celular/fisiologia , Membrana Celular/ultraestrutura , Células Cultivadas , Cricetinae , Relação Dose-Resposta a Droga , Rim/efeitos dos fármacos , Rim/ultraestrutura , Microscopia Eletrônica , Mitocôndrias/metabolismo , Mitocôndrias/fisiologia , Mitocôndrias/ultraestrutura , Oxirredução , Fatores de TempoRESUMO
The mycotoxin citrinin, depressed the phosphorylation efficiency of liver mitochondria as deduced from a decrease of respiratory coefficient and of the ADP/O ratio. Citrinin (1.0 mM) inhibited some enzymes linked to the respiratory chain, namely NADH oxidase and NADH cytochrome c reductase involved with complex I. The activities of enzymes related with other enzymatic complexes of the respiratory chain were either unaffected or enhanced. ATPase activity was inhibited by the mycotoxin. Malate, glutamate, and 2-oxoglutarate dehydrogenases were also inhibited. The transmembrane potential (delta psi), developed by energized mitochondria and depolarization on the addition of ADP, was decreased. The results suggest that citrinin promotes a partial dissipation of the transmembrane potential, different from that resulting from a classical uncoupler such as 2,4-dinitrophenol.