A neuronal nitric oxide synthase inhibitor 7-nitroindazole reduces the 5-HT1A receptor against 8-OH-DPAT-elicited hyperphagia in rats.
The effects of the neuronal nitric oxide (NO) synthase inhibitor 7-nitroindazole on 8-hydroxy-2-di-n-(propylamino)tetralin (8-OH-DPAT)-induced hyperphagia, which is mediated by the 5-HT1A autoreceptor, were investigated in rats. 7-Nitroindazole suppressed 8-OH-DPAT-elicited increases in food intake. The inhibitory effects of 7-nitroindazole on 8-OH-DPAT-induced feeding were prevented by the NO precursor L-arginine. Although 8-OH-DPAT decreases 5-hydroxytryptamine (5-HT) synthesis, 7-nitroindazole did not reverse the 8-OH-DPAT-elicited decrease in 5-HT synthesis. Therefore, these results indicate that NO formed in the brain is involved in 8-OH-DPAT-induced hyperphagia and that the hypophagic effects of 7-nitroindazole are not dependent on 5-HT synthesis.
Sugimoto
Y
Y
Department of Pharmacology, Kobe Pharmaceutical University, Japan.
Yamada
J
J
Yoshikawa
T
T
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000633:toxicity; D000818:Animals; D001120:Arginine / Q000494:pharmacology; D017660:Autoreceptors / Q000819:agonists*; D004791:Enzyme Inhibitors / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects; D006930:Hyperalgesia / Q000139:chemically induced / Q000378:metabolism* / Q000503:physiopathology*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D007191:Indazoles / Q000494:pharmacology*; D008297:Male; D009474:Neurons / Q000201:enzymology; 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 / Q000096:biosynthesis; D017366:Serotonin Receptor Agonists / Q000633:toxicity
D017660:Autoreceptors; D004791:Enzyme Inhibitors; D007191:Indazoles; D011985:Receptors, Serotonin; D044263:Receptors, Serotonin, 5-HT1; D017366:Serotonin Receptor Agonists; D012701:Serotonin; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D001120:Arginine; D019001:Nitric Oxide Synthase; C080122:7-nitroindazole