Involvement of brain transmitters in the modulation of shock-induced aggression in rats by propranolol and related drugs.
(+/-)Propranolol (1, 3, 10 and 30 mg/kg) exhibited a differential effect on footshock aggression (FSA) in rats. Lower doses (1 and 3 mg/kg) of the drug facilitated FSA, whereas an inhibitory effect was observed with higher doses (10 and 30 mg/kg) of the same. (+)Propranolol (30 mg/kg) and UM-272 (1 and 10 mg/kg) as well as physostigmine (0.1 and 0.5 mg/kg) all produced inhibition of FSA. Similar FSA inhibitory effects were also observed with salbutamol (1 and 5 mg/kg). Pretreatment with atropine and not methylatropine attenuated the anti-aggressive effect of (+/-)propranolol (10 mg/kg) without appreciably altering the facilitatory effect (1 mg/kg) of the drug on FSA. In addition, at the anti-aggressive doses, (+/-)propranolol (10 mg/kg) and UM-272 (10 mg/kg), significantly inhibited brain cholinesterase enzyme activity when compared to saline controls. (+/-)Propranolol (10 mg/kg) also inhibited significantly the aggression induced by reserpine-apomorphine treatment. It is inferred that a central cholinergic and dopaminergic mechanism is involved in the anti-aggressive effect of (+/-)propranolol, whereas the low dose induced facilitation of affective aggression could be attributed to central beta-adrenoceptor blockade.
D000110:Acetylcholinesterase / Q000378:metabolism*; D000374:Aggression / Q000187:drug effects*; D000420:Albuterol / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001921:Brain / Q000201:enzymology*; D004597:Electroshock; D008297:Male; D010830:Physostigmine / Q000494:pharmacology; D011433:Propranolol / Q000031:analogs & derivatives* / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains
C002616:pranolium; D001285:Atropine; D010830:Physostigmine; D011433:Propranolol; D000110:Acetylcholinesterase; D000420:Albuterol