Effect of intraperitoneally administered GABA on the locomotor activity of mice.
Gammaaminobutyric acid (GABA) was injected intraperitoneally (i.p.) into mice at doses from 25--2000 mg/kg, and spontaneous locomotor activity was recorded for the following 20 min. A slight but significant decrease in the spontaneous locomotor activity was noted only with the highest dose. The stimulation of motor activity induced by ethanol (2.4 g/kg i.p.) was significantly counteracted by GABA (100 mg/kg i.p. and upwards). A further suppression of ethanol-induced hyperactivity was reached by pretreatment with aminooxyacetic acid (AOAA, 15 mg/kg i.p.). The stimulation of motor activity induced by morphine (10 mg/kg i.p.) remained unaffected by even high doses of i.p. GABA. Motility produced by activation of postsynaptic catecholamine receptors, i.e., by apomorphine (3 mg/kg i.p.) and clonidine (3 mg/kg i.p.) following reserpine (10 mg/kg i.p.) and alpha-methyltyrosine (250 mg/kg i.p.) pretreatment, was not affected by i.p. GABA injections, whereas hypomotility caused by a low dose of haloperidol (150 microgram/kg i.p.) was enhanced. In conjunction with earlier biochemical data, these results suggest a certain access of blood-borne GABA to the CNS, leading to inhibition of dopaminergic neurons involved in motility regulation.
D000625:Aminooxyacetic Acid / Q000494:pharmacology; D000818:Animals; D003864:Depression, Chemical; D004347:Drug Interactions; D000431:Ethanol / Q000494:pharmacology; D005260:Female; D007274:Injections, Intraperitoneal; D051379:Mice; D009043:Motor Activity / Q000187:drug effects*; D011950:Receptors, Cholinergic / Q000187:drug effects; D005680:gamma-Aminobutyric Acid / Q000008:administration & dosage / Q000494:pharmacology*
D011950:Receptors, Cholinergic; D000625:Aminooxyacetic Acid; D000431:Ethanol; D005680:gamma-Aminobutyric Acid