Inhibitory effects of tryptamine on tolbutamide-induced hypoglycemia in mice: mediation by 5-HT receptors.
Effects of tryptamine on tolbutamide-induced hypoglycemia were investigated in mice. Tryptamine significantly inhibited hypoglycemia elicited by tolbutamide. The inhibitory effects of tryptamine were strongly blocked by the 5-HT1 and 5-HT2 receptor antagonist methysergide and the 5-HT2 receptor antagonist ketanserin, while the 5-HT3 receptor antagonist ICS 205-930 was without effect. Tryptamine induced hyperglucagonemia in tolbutamide-treated mice, and this effect elicited by tryptamine was strongly inhibited by the 5-HT2 receptor antagonist ketanserin. These results suggest that the inhibitory effects of tryptamine on tolbutamide-induced hypoglycemia are mediated by 5-HT2 receptors and that tryptamine is involved in glucagon release.
Sugimoto
Y
Y
Department of Pharmacology, Kobe Women's College of Pharmacy, Japan.
Yamada
J
J
Kimura
I
I
Watanabe
Y
Y
Horisaka
K
K
D000818:Animals; D001786:Blood Glucose / Q000187:drug effects* / Q000378:metabolism; D007003:Hypoglycemia / Q000097:blood* / Q000139:chemically induced; D007211:Indoles / Q000494:pharmacology; D007650:Ketanserin / Q000494:pharmacology; D008297:Male; D008784:Methysergide / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D011985:Receptors, Serotonin / Q000502:physiology*; D012702:Serotonin Antagonists / Q000494:pharmacology; D013997:Time Factors; D014044:Tolbutamide / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D000077526:Tropisetron; D014363:Tryptamines / Q000494:pharmacology*
D001786:Blood Glucose; D007211:Indoles; D011985:Receptors, Serotonin; D012702:Serotonin Antagonists; D014363:Tryptamines; C030820:tryptamine; D000077526:Tropisetron; D007650:Ketanserin; D014044:Tolbutamide; D008784:Methysergide