Effect of baclofen, a GABAB-agonist, on forced swimming-induced immobility in mice.
The effect of baclofen, a GABAB-agonist, was studied on both forced swimming-induced immobility and isoprenaline-induced enhancement of forced swimming-induced immobility in mice. (+/-) Baclofen (0.5 and 1 mg/kg), and (-) baclofen (0.5, 1 and 2 mg/kg) attenuated forced swimming-induced immobility. The effect of baclofen was not reversed by bicuculline, a GABAA-antagonist. Baclofen also reduced isoprenaline-induced enhancement of forced swimming-induced immobility. On concomitant administration of a subeffective dose of baclofen with a subeffective dose of propranolol, desipramine and amitriptyline, a potentiating effect was observed. These results are corroborative of our previous finding that GABAergic agents, particularly GABAB-receptors, play a role in the modulation of despair behavior in mice and in the action of antidepressant drugs. Baclofen (5 mg/kg) did not produce any significant effect on forced swimming-induced immobility, but reduced significantly the locomotor activity of the animals. Lower doses (0.5 and 1 mg/kg) of baclofen, which reduced the forced swimming-induced immobility, did not affect the locomotor activity. At higher and lower tissue concentrations of the drug, involvement of different receptor populations is suggested.
Aley
K O
KO
Department of Pharmaceutical Sciences, Panjab University, Chandigarh, India.
Kulkarni
S K
SK
D000639:Amitriptyline / Q000494:pharmacology; D000818:Animals; D001418:Baclofen / Q000494:pharmacology*; D001640:Bicuculline / Q000494:pharmacology; D003891:Desipramine / Q000494:pharmacology; D004347:Drug Interactions; D005260:Female; D007545:Isoproterenol / Q000494:pharmacology; D008297:Male; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D009129:Muscle Tonus / Q000187:drug effects; D004856:Postural Balance / Q000187:drug effects; D011433:Propranolol / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D011963:Receptors, GABA-A / Q000187:drug effects; D012110:Reserpine / Q000494:pharmacology; D013237:Stereoisomerism; D013315:Stress, Psychological / Q000523:psychology*; D013550:Swimming
D011963:Receptors, GABA-A; D000639:Amitriptyline; D012110:Reserpine; D011433:Propranolol; D001418:Baclofen; D007545:Isoproterenol; D003891:Desipramine; D001640:Bicuculline