Efeito da inGestão alimentar estimulada por jejum ou neuropeptidio Y sobre a liberacao hipotalamica de seratonina, em ratos normais e obesos

Efeito da inGestão alimentar estimulada por jejum ou neuropeptidio Y sobre a liberacao hipotalamica de seratonina, em ratos normais e obesos

Alternative title Effect of fasting or NPY-induced food intake on hypothalamic serotonin release in normal and obese rats
Author Mori, Rosana Cristina Tieko Autor UNIFESP Google Scholar
Abstract The hypothalamic serotonergic system is involved in the regulation of food ingestion and energy metabolism. Since disturbances of both energy intake and expenditure can contribute to obesity, the first objective of the present study was to evaluate the lateral hypothalamic serotonergic response, stimulated by deprivation-induced food ingestion, in two models of obesity: the hyperphagic Zucker and the hypophagic/hypometabolic monosodium glutamate (MSG)-obese Wistar rat. Since neuropeptide Y (NPY) and 5-HT have opposite effects on energy homeostasis, we also examined their possible functional interaction by examining the serotonergic response to NPY-induced feeding. Fasting-induced food intake significantly increased 5-HT release in normal and obese rats of both strains. Importantly, the response was similar to (MSG-obese) or even higher than (Zucker-obese) that seen in the respective lean controls. The results indicate that the energy homeostasis disturbances of both these obesity models may not be ascribed to an impairment of the acute lateral hypothalamic serotonin response to a dietary stimulus. When food consumption was stimulated by NPY in normal rats, the serotonergic response was preservei when NPY induced an amount of feeding similar to that induced by fasting. Abolition of the increased 5-HT release was seen only when the NPY-induced feeding was in excess to the fasting-induced one. On the other hand, in both MSG and Zucker obese animais, the response was abolished even in the presence of a food intake similar to that induced by fasting. These data indicate that the orexigenic effect of NPY relies, at least in part, on its ability to abolish the feeding inhibitory influence of 5-HT. ln obese rats, the apparent higher than normal sensitivity to this effect may contribute to their impaired energy homeostasis
Keywords Serotonina
Obesidade
Neuropeptídeo Y
Language Portuguese
Date 1999
Published in São Paulo: [s.n.], 1999. 73 p. ilus., tab.
Publisher Universidade Federal de São Paulo (UNIFESP)
Extent 73 p.
Access rights Closed access
Type Dissertation
URI http://repositorio.unifesp.br/handle/11600/16260

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