Microinjections of growth hormone-releasing factor into the medial preoptic area/suprachiasmatic nucleus region of the hypothalamus stimulate food intake in rats.
The role of the suprachiasmatic nucleus/medial preoptic area region of the hypothalamus in the expression of rat hypothalamic growth hormone-releasing factor-induced feeding in the rat was examined. Rats were tested for their 90-min food intake following microinjections of growth hormone-releasing factor (0.0, 0.01, 0.1 or 1.0 pmol) aimed at the suprachiasmatic nucleus/medial preoptic area region. It was found that growth hormone-releasing factor dose-dependently stimulated food intake with the 1.0 pmol dose being the most effective, increasing food intake by approximately 200%. Injections outside the suprachiasmatic nucleus/medial preoptic area region were ineffective. These data are taken to suggest that the suprachiasmatic nucleus/medial preoptic area region of the hypothalamus is important for the central stimulatory effects of growth hormone-releasing factor on feeding.
D000818:Animals; D001066:Appetite / Q000187:drug effects*; D013007:Growth Hormone-Releasing Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D008297:Male; D008845:Microinjections; D011301:Preoptic Area / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D011919:Rats, Inbred Strains; D012016:Reference Values; D013493:Suprachiasmatic Nucleus / Q000187:drug effects / Q000502:physiology*
D013007:Growth Hormone-Releasing Hormone