Beta 2- but not beta 1-adrenoceptors are involved in desipramine enhancement of aggressive behavior in long-term isolated mice.
The effects of several beta-adrenoceptor antagonists on the desipramine-induced increase in aggressive behavior in long-term isolated mice were examined. Desipramine HCl (10 mg/kg, IP) significantly increased the duration of aggressive behavior in isolated mice but did not significantly change the latency to the first attack consistent with our previous reports. Intraperitoneal administration of (+/- )propranolol HCl (2.5-10 mg/kg), a nonselective beta-adrenoceptor antagonist, dose dependently attenuated the desipramine-induced enhancement of aggressive behavior without significantly affecting the basal aggressive responses. ICI118,551 HCl (1.25-5 mg/kg, IP), a selective beta 2-adrenoceptor antagonist, also blocked the desipramine-induced enhancement of aggressive behavior in a dose-dependent manner, whereas metoprolol tartrate (5-20 mg/kg, IP), a selective beta 1-adrenoceptor antagonist, did not affect it. Moreover, clenbuterol HCl (0.1-0.5 mg/kg, IP), a lipophilic beta 2-adrenoceptor agonist, significantly increased the duration of basal aggressive behavior. Taken together with our previous finding that the desipramine-induced enhancement of aggressive behavior can be blocked by yohimbine, an alpha 2-adrenoceptor antagonist, the present results indicate that not only alpha 2- but also beta 2-adrenoceptor stimulation plays important roles in modulation of aggressive behavior in long-term isolated mice.
Matsumoto
K
K
Division of Pharmacology, Toyama Medical and Pharmaceutical University, Japan.
Ojima
K
K
Ohta
H
H
Watanabe
H
H
D000374:Aggression / Q000187:drug effects*; D000818:Animals; D002976:Clenbuterol / Q000494:pharmacology; D003891:Desipramine / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D008297:Male; D008790:Metoprolol / Q000494:pharmacology; D051379:Mice; D008815:Mice, Inbred Strains; D011433:Propranolol / Q000494:pharmacology; D018342:Receptors, Adrenergic, beta-1 / Q000187:drug effects*; D018343:Receptors, Adrenergic, beta-2 / Q000187:drug effects*; D012934:Social Isolation
D018342:Receptors, Adrenergic, beta-1; D018343:Receptors, Adrenergic, beta-2; D011433:Propranolol; D008790:Metoprolol; D003891:Desipramine; D002976:Clenbuterol