Dehydroepiandrosterone regulates insulin-like growth factor-1 system in adult rat hypothalamus.
Dehydroepiandrosterone (DHEA) and its sulfate ester (DHEA-S) exert multiple effects in rodent and human brain. Several findings suggest that insulin-like growth factor-1 (IGF-1) is involved in the actions of DHEA. In this study, we assessed whether systemic administration of DHEA regulates the IGF-1 system in the hypothalamus, hippocampus, cerebral cortex, and cerebellum of adult rats. DHEA resulted in a significant reduction in IGF-1 receptor protein levels. This effect was dose dependent and restricted to the hypothalamus. In contrast to IGF-1 receptor, IGF-1-binding protein 2 levels were unaffected by DHEA treatment. IGF-1 levels were significantly increased in the hypothalamus of the rats treated with DHEA, whereas IGF-1 serum levels were not affected by DHEA. The effects of DHEA on the hypothalamic IGF-1 system may be highly relevant to the control and maintenance of hypothalamic neuroendocrine function.
Ribeiro
Maria Flavia
MF
Departamento de Fisiologia, ICBS, Universidade Federal do Rio Grande do Sul, Porto Alegre, Brazil.
Garcia-Segura
Luis Miguel
LM
D000818:Animals; D015153:Blotting, Western; D002531:Cerebellum / Q000187:drug effects / Q000378:metabolism; D002540:Cerebral Cortex / Q000187:drug effects / Q000378:metabolism; D003687:Dehydroepiandrosterone / Q000494:pharmacology*; D006624:Hippocampus / Q000187:drug effects / Q000378:metabolism; D007031:Hypothalamus / Q000187:drug effects* / Q000378:metabolism; D018971:Insulin-Like Growth Factor Binding Protein 2 / Q000378:metabolism; D007334:Insulin-Like Growth Factor I / Q000378:metabolism*; D008297:Male; D011863:Radioimmunoassay; D051381:Rats; D017208:Rats, Wistar; D017526:Receptor, IGF Type 1 / Q000378:metabolism
D018971:Insulin-Like Growth Factor Binding Protein 2; D003687:Dehydroepiandrosterone; D007334:Insulin-Like Growth Factor I; D017526:Receptor, IGF Type 1