Effects of glucagon, Neurotensin, and vasoactive intestinal polypeptide on somatostatin release from perifused rat hypothalamus.
The effects of neuropeptides on the release of immunoreactive somatostatin (SRIF) from the rat hypothalamus were examined in vitro using a perifusion system. Twelve hypothalamic halves of male rats were placed on a Sephadex G-25 column and continuously eluted with Krebs-Ringer bicarbonate buffer, poH 7.4, at 37 C. A high potassium concentration (56 mM) stimulated SRIF release in a calcium-dependent manner. The infusion of glucagon (10(-7), 5 x 10(-7), and 10(-6) M) resulted in a dose-related increase in the release of SRIF. Neurotensin (10(-6) M) also stimulated SRIF release, whereas vasoactive intestinal polypeptide (10(-7) and 10(-6) M) inhibited SRIF release. SRIF release was not affected by cholecystokinin-octapeptide (10(-6) M), cholecystokinin-tetrapeptide (10(-6) M), or tRH (10(-6) M). These findings suggest that SRIF release from the rat hypothalamus is influenced by glucagon, neurotensin, and vasoactive intestinal polypeptide.
D000818:Animals; D002766:Cholecystokinin / Q000494:pharmacology; D005768:Gastrointestinal Hormones / Q000494:pharmacology*; D005934:Glucagon / Q000494:pharmacology*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D009496:Neurotensin / Q000494:pharmacology*; D011188:Potassium / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013004:Somatostatin / Q000378:metabolism*; D013997:Time Factors; D014660:Vasoactive Intestinal Peptide / Q000494:pharmacology*
D005768:Gastrointestinal Hormones; D014660:Vasoactive Intestinal Peptide; D009496:Neurotensin; D013004:Somatostatin; D005934:Glucagon; D002766:Cholecystokinin; D011188:Potassium