[The GABA-ergic system of the myometrium: a basis for the clinical study of GABA-positive substances as pregnancy protectors].

Radioligand method was used to show 14C-GABA, 3H-flunitrazepam binding sites in human, rat, rabbit myometrium. We have used muscimol, bicucullin, picrotoxin, baclofen, thiosemicarbazide for identification of GABA-benzodiazepine receptor complexes and in pharmacologic analysis of uterine contractility. Receptor affinity depended on pregnancy term (early or late). A conclusion is drawn that GABAA, GABAB, and benzodiazepine receptors of the peripheral nervous system mediate the inhibitory effect of GABA-positive substances on mammalian uterine contractility.