A nitric oxide synthase inhibitor reduces hyperphagia induced in rats by the 5-HT(1A) receptor agonist, 8-OH-DPAT, independently of hypothalamic serotonin metabolism.
In rats, a nitric oxide (NO) synthase inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME) inhibited the hyperphagia induced by the 5-hydroxytryptamine (5-HT)(1A) autoreceptor agonist, 8-hydroxy-2-di-n-(propylamino)tetralin (8-OH-DPAT). 8-OH-DPAT reduced 5-HT metabolism in the hypothalamus, and this was not blocked by pretreatment with L-NAME. L-NAME also did not affect basal hypothalamic 5-HT metabolism or reverse the decreases in 5-HT synthesis in hypothalamus. These results suggest that the hypophagic effects of L-NAME, which inhibits NO formation, are independent of 5-HT metabolism in the hypothalamus.
Yamada
J
J
Department of Pharmacology, Kobe Pharmaceutical University, Motoyamakita-machi, Higashinada-ku, 658-8558, Kobe, Japan. j-yamada@kobepharma-u.ac.jp
Sugimoto
Y
Y
Kunitomo
M
M
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000037:antagonists & inhibitors* / Q000494:pharmacology; D000818:Animals; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D006897:Hydroxyindoleacetic Acid / Q000378:metabolism; D006963:Hyperphagia / Q000523:psychology*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism*; D008297:Male; D019001:Nitric Oxide Synthase / Q000037:antagonists & inhibitors*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000187:drug effects*; D044263:Receptors, Serotonin, 5-HT1; D012701:Serotonin / Q000378:metabolism*; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
D004791:Enzyme Inhibitors; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D006897:Hydroxyindoleacetic Acid; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D019001:Nitric Oxide Synthase