RESUMO
The hepatoprotective effects of the ethanolic extracts of propolis (EEP) on alcohol-induced liver steatosis were investigated in Wistar rats. Chronic alcoholic fatty liver was induced by administration of 52% alcohol to male Wistar rats at the dose of 1% body weight for 7 weeks. Then animals were simultaneously treated with 50% ethanol solutions of EEP or normal saline at the dose of 0.1% body weight for 4 further weeks. Serological analyses and liver histopathology studies were performed to investigate the development of steatosis. Microarray analysis was conducted to investigate the alterations of hepatic gene expression profiling. Our results showed that 4-week treatment of EEP helped to restore the levels of various blood indices, liver function enzymes and the histopathology of liver tissue to normal levels. Results from the microarray analysis revealed that the hepatic expressions of genes involved in lipogenesis were significantly down-regulated by EEP treatment, while the transcriptional expressions of functional genes participating in fatty acids oxidation were markedly increased. The ability of EEP to reduce the negative effects of alcohol on liver makes propolis a potential natural product for the alternative treatment of alcoholic fatty liver.
Assuntos
Fígado Gorduroso Alcoólico/metabolismo , Hepatopatias Alcoólicas/metabolismo , Extratos Vegetais/metabolismo , Própole/metabolismo , Substâncias Protetoras/metabolismo , Alanina Transaminase/metabolismo , Animais , Apiterapia/métodos , Aspartato Aminotransferases/metabolismo , Colesterol/metabolismo , Modelos Animais de Doenças , Etanol , Ácidos Graxos/biossíntese , Fígado Gorduroso Alcoólico/tratamento farmacológico , Fígado Gorduroso Alcoólico/genética , Fígado Gorduroso Alcoólico/patologia , Hepatopatias Alcoólicas/tratamento farmacológico , Hepatopatias Alcoólicas/genética , Hepatopatias Alcoólicas/patologia , Masculino , Oxirredução , Extratos Vegetais/química , Extratos Vegetais/uso terapêutico , Própole/química , Própole/uso terapêutico , Substâncias Protetoras/química , Substâncias Protetoras/uso terapêutico , Ratos Wistar , Análise Serial de Tecidos/métodos , Transcrição Gênica/genética , Triglicerídeos/metabolismoRESUMO
This study was designed to investigate the physiological and biochemical responses of Brandt's voles to the persistent presence of dietary tannic acid. The diet for animals in the experimental group was supplemented with 3% dietary tannic acid for 5weeks. The control group received a commercial lab chow. No significant differences were detected in body weight, organ (heart, kidney, and liver) weights, and organ parameters between animals from two groups. However, voles in the experimental group had significantly higher daily food intake, increased contents of proline and histidine in saliva and feces after protein hydrolysis, and elevated hepatic expression of transferrin than the control. Our results suggested the existence of adaptive strategies developed in Brandt's voles to overcome the adverse effects of dietary tannic acid. (1) Food consumption was increased to satisfy their nutritional demands. (2) The secretion of tannic-acid-binding salivary proteins was promoted. (3) The absorption of iron was enhanced. These alterations contributed to neutralize the negative effects of tannic acid and maintain body mass in animals supplemented with tannic acid. As the result of the consumption of tannic acid, hepatic expression of 3-hydroxy-3-methylglutaryl coenzyme A reductase was significantly decreased, while the overall potential of the antioxidant system, characterized by increased hepatic enzymatic activities of catalase and glutathione peroxidase, was enhanced. Our results also implied the involvement of tannic acid in the regulation of lipid metabolism and oxidative stress in voles.
Assuntos
Antioxidantes/metabolismo , Arvicolinae/crescimento & desenvolvimento , Arvicolinae/metabolismo , Dieta , Regulação da Expressão Gênica/efeitos dos fármacos , Fígado/efeitos dos fármacos , Taninos/farmacologia , Animais , Arvicolinae/genética , Peso Corporal/efeitos dos fármacos , Ingestão de Alimentos/efeitos dos fármacos , Amplificação de Genes/efeitos dos fármacos , Hidroximetilglutaril-CoA Redutases/genética , Fígado/enzimologia , Fígado/crescimento & desenvolvimento , Fígado/metabolismo , Tamanho do Órgão/efeitos dos fármacos , Transferrina/genéticaRESUMO
Predator odors are non-intrusive natural stressors of high ethological relevance. The objective of this study was to investigate the processing of a chronic, life-threatening stimulus during repeated prolonged presentation to Brandt's voles. One hundred and twenty voles were tested by repeated presentation of cat feces in a defensive withdrawal apparatus. Voles exposed to feces for short periods showed more avoidance, more concealment in the hide box, less contact time with the odor source, more freezing behavior, less grooming, more jumping, and more vigilant rearing than did non-exposed voles, and those exposed for longer periods. Serum levels of adrenocorticotropic hormone and corticosterone increased significantly when animals were repeatedly exposed to cat feces for short periods. The behavioral and endocrine responses habituated during prolonged presentation of cat feces. ΔfosB mRNA expression level was highest in voles exposed to cat feces for 6 and 12 consecutive days, and subsequently declined in animals exposed to cat feces for 24 days. We therefore conclude that the behavioral and endocrine responses to repeated exposure to cat feces undergo a process of habituation, while ΔfosB changes in the medial hypothalamic region exhibit sensitization. We propose that habituation and sensitization are complementary rather than contradictory processes that occur in the same individual upon repeated presentation of the same stressor.
Assuntos
Arvicolinae/fisiologia , Arvicolinae/psicologia , Mecanismos de Defesa , Estresse Psicológico , Hormônio Adrenocorticotrópico/sangue , Animais , Gatos , Corticosterona/sangue , Fezes , Regulação da Expressão Gênica/fisiologia , Hipotálamo/metabolismo , Odorantes , Proteínas Proto-Oncogênicas c-fos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Estresse Psicológico/sangue , Estresse Psicológico/patologia , Estresse Psicológico/psicologiaRESUMO
Predator odors are non-intrusive natural stressors of high ethological relevance. Animals are daily challenged with stressors of varying intensity and it is essential for their survival to respond to a wide range of threats. Behavioral and hormonal responses and changes in the level of medial hypothalamic c-fos mRNA were examined in Brandt's voles (Lasiopodomys brandtii) exposed to the feces of a domestic cat (Felis catus) stored for different periods. One hundred voles were tested in the defensive withdrawal apparatus. The voles showed an aversion to freshly collected cat feces, indicated by high levels of flight-related behaviors, increased freezing behavior, and more vigilant rearing compared to old feces. The serum levels of adrenocorticotropic hormone and corticosterone significantly increased when the voles were exposed to fresh cat feces. The level of c-fos mRNA in the medial hypothalamic region was highest in the individuals exposed to fresh cat feces. All of these behavioral, endocrine and c-fos-mRNA responses were lower when voles were subjected to older cat feces. We conclude that these responses depend on volatile chemical constituents of cat feces rather than their physical characteristics and that this accounts for the lower responses to feces stored for longer periods.
Assuntos
Arvicolinae/fisiologia , Arvicolinae/psicologia , Mecanismos de Defesa , Fezes , Hormônio Adrenocorticotrópico/metabolismo , Análise de Variância , Animais , Gatos , Corticosterona/metabolismo , Feminino , Hipotálamo/metabolismo , Masculino , Odorantes , Proteínas Proto-Oncogênicas c-fos/genética , RNA Mensageiro/metabolismo , RatosRESUMO
AIM: To investigate the influence of hypoxia on postnatal developing pattern of hypothalamic corticotropin releasing factor(CRF) and arginine vasopressin (AVP) in male and female neonatal rats. METHODS: The hypoxia was simulated in hypobaric cabin. The content of AVP and CRF was assayed by RIA method. RESULTS: It was showed the female rats had the similar developing process with male rats, either at 2300 m or at 5000 m altitude. When they developed at simulated 5000 m altitude, the content of their hypothalamic CRF was lower than that of control rats on postnatal day 21, while the content of AVP was higher than control on day 21 and 28. CONCLUSION: Maybe the difference of the function between hypothalamic CRF and AVP or/and the incoherence of their developing stage contribute to their particular developing pattern at 5000 m altitude.
Assuntos
Altitude , Arginina Vasopressina/metabolismo , Hormônio Liberador da Corticotropina/metabolismo , Hipotálamo/metabolismo , Hipóxia , Animais , Animais Recém-Nascidos , Feminino , Masculino , Ratos , Ratos WistarRESUMO
AIM: To investigate the response of hypothalamic corticotropin releasing factor (CRF) and arginine vasopressin (AVP) of adrenalectomized neonatal rats to hypoxia. METHODS: The hypoxia was simulated in hypobaric cabin. The amount of arginine vasopressin (AVP) and corticotropin releasing factor (CRF) was assayed by RIA method. RESULTS: When neonatal rats exposed to acute hypoxia (simulated altitude of 5 000 m and 7 000 m, 24 h), their hypothalamic CRF was not changed in 3 d and 7 d rats, lower than control in 14 d, 21 d and 28 d rats, while hypothalamic AVP had no change in 3 d rats, was lower than control in 14 d and higher in 7 d, 21 d and 28 d rats. The responsive pattern of those two neuropeptides to acute hypoxia changed with the growth of rats. Adrenalectomy reduced the amount of hypothalamic CRF and AVP in 14 d, 21 d and 28 d rats, except AVP in 28 d rats. When adrenalectomized neonates exposed to hypoxia, there was no further change in CRF and AVE, means adrenalectomy not only removed the negative regulation of corticosteroid on CRF and AVE, but also inhibited the normal development of CRF and AVP neurons and thus, their responsive ability to hypoxia.