The effects of GABA-ergic drugs on enkephalin-induced motor seizure phenomena in the rat.
1. The relationship between the effects of GABA-ergic drugs and D-ala2-met-enkephalinamide (DALA)-induced myoclonic contractions of inframandibular muscles has been studied in the rat. 2. GABA-ergic drugs altered enkephalin-induced myoclonic contractions in the following manner: (a) The GABA-mimetic drugs, muscimol, gabaculine and baclofen, decreased DALA-induced myoclonic contractions. (b) The GABA antagonist, bicuculline and the anticonvulsant substance, sodium valproate (dipropylacetic acid, DPA) potentiated DALA-induced myoclonic contractions. The potentiating effect of DPA is probably due to its opiate-like activity, since naloxone abolished this effect. 3. The modulatory effect of the GABA-mimetic drug on enkephalin-induced myoclonic contractions may give grounds for further study to test the possible use of other GABA-mimetic drugs and possibly opiate antagonists for the treatment of myoclonic syndromes.
D000818:Animals; D001418:Baclofen / Q000494:pharmacology; D003509:Cyclohexanecarboxylic Acids / Q000494:pharmacology; D003514:Cyclohexylamines / Q000494:pharmacology; D004723:Endorphins / Q000494:pharmacology*; D004745:Enkephalins / Q000494:pharmacology*; D005260:Female; D008297:Male; D009118:Muscimol / Q000494:pharmacology; D009207:Myoclonus / Q000139:chemically induced*; D051381:Rats; D011956:Receptors, Cell Surface / Q000502:physiology; D011963:Receptors, GABA-A; D014635:Valproic Acid / Q000494:pharmacology; D005680:gamma-Aminobutyric Acid / Q000494:pharmacology*
D003509:Cyclohexanecarboxylic Acids; D003514:Cyclohexylamines; D004723:Endorphins; D004745:Enkephalins; D011956:Receptors, Cell Surface; D011963:Receptors, GABA-A; D009118:Muscimol; C012987:gabaculine; D005680:gamma-Aminobutyric Acid; D014635:Valproic Acid; D001418:Baclofen