Influence of alpha-adrenoceptor agonists and antagonists on imipramine-induced hypothermia in mice.
Effects of adrenoceptor agonists and antagonists on imipramine-induced hypothermia in mice were studied. Intraperitoneal injection of imipramine (10-40 mg x kg(-1)), alpha2-adrenoceptor agonist clonidine (0.05-0.1 mg x kg(-1)), alpha1-adrenoceptor agonist phenylephrine (6 mg x kg(-1)) and alpha1-adrenoceptor antagonist prazosin (1-4 mg x kg(-1)) but not alpha2-adrenoceptor antagonist yohimbine (1-4 mg x kg(-1)) induced significant hypothermia. The hypothermic response induced by imipramine (10-30 mg x kg(-1)) was not altered by clonidine (0.05-0.1 mg x kg(-1)) or phenylephrine (2-6 mg x kg(-1)). The response of imipramine (10-30 mg x kg(-1)) was reduced significantly by yohimbine (2 mg x kg(-1)) and was potentiated by prazosin (1 mg x kg(-1)). The hypothermic effect of clonidine (0.1 mg x kg(-1)) and imipramine (20 mg x kg(-1)) were also decreased significantly by different doses of yohimbine (1-4 mg x kg(-1)). The hypothermia induced by different doses of prazosin (1-4 mg x kg(-1)) was not altered by yohimbine (2 mg x kg(-1)) or by low dose of imipramine (10 mg x kg(-1)). It is concluded that alpha2-adrenoceptor mechanism may be involved in the hypothermic effect of imipramine.
Zarrindast
Mohammad-Reza
MR
Department of Pharmacology, School of Medicine, Tehran University of Medical Science, Tehran, Iran. zarinmr@ams.ac.ir
Sadeghi
Sheyda
S
Sahebgharani
Mousa
M
D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology*; D000818:Animals; D000929:Antidepressive Agents, Tricyclic / Q000009:adverse effects*; D001831:Body Temperature / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D007035:Hypothermia / Q000139:chemically induced* / Q000503:physiopathology; D007099:Imipramine / Q000009:adverse effects*; D008297:Male; D051379:Mice
D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D000929:Antidepressive Agents, Tricyclic; D007099:Imipramine