Effects of adrenoceptor agents on apomorphine-induced licking behavior in rats.
In the present study, intraperitoneal (IP) administration of the dopaminergic receptor agonist apomorphine (0.1, 0.25, and 0.5 mg/kg) induced a dose-dependent licking in rats. The intraperitoneal injection of the alpha1'''adrenoceptor agonist phenylephrine (1-8 mg/kg) but not the alpha2-adrenoceptor agonist clonidine (0.025-0.05 mg/kg) decreased licking induced by apomorphine. The alpha-adrenoceptor antagonists prazosin, phenoxybenzamine, and yohimbine also reduced the apomorphine response significantly. The response induced by phenylephrine was decreased by a dose of prazosin. The beta1-adrenenocepor agonist dobutamine and beta2-adrenenocepor agonist salbutamol did not alter the apomorphine response. However, beta2-adrenenocepor antagonists atenolol and propranolol reduced the apomorphine effect. It may be concluded that alpha1- and possibly beta1-adrenoceptor mechanisms may be involved in modulation of licking behavior.
Zarrindast
M R
MR
Department of Pharmacology, School of Medicine, Tehran University of Medical Sciences, Iran.
Fazli-Tabaei
S
S
Semnanian
S
S
Fathollah
Y
Y
Yahyavi
S H
SH
D018663:Adrenergic Agents / Q000494:pharmacology*; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000317:Adrenergic alpha-Antagonists / Q000494:pharmacology; D000818:Animals; D001058:Apomorphine / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D001522:Behavior, Animal / Q000187:drug effects* / Q000502:physiology; D018491:Dopamine Agonists / Q000494:pharmacology*; D008297:Male; D009043:Motor Activity / Q000187:drug effects* / Q000502:physiology; D010656:Phenylephrine / Q000037:antagonists & inhibitors / Q000494:pharmacology; D011224:Prazosin / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D011941:Receptors, Adrenergic / Q000187:drug effects* / Q000502:physiology
D018663:Adrenergic Agents; D000316:Adrenergic alpha-Agonists; D000317:Adrenergic alpha-Antagonists; D018491:Dopamine Agonists; D011941:Receptors, Adrenergic; D010656:Phenylephrine; D001058:Apomorphine; D011224:Prazosin