GABA-ergic mechanisms in the anticonvulsive activity of newly synthesized barbiturates. II. Correlation of HB-7 with GABA-ergic agents.

The effect of the newly synthesized barbiturate HB-7 (2-hydroxylamino-5-ethyl-5-sec. pentylbarbituric acid) was investigated in experiments on mice in comparison with the effect of pentobarbital (PB), as well as their correlations with agents potentiating GABA-ergic transmission: GABA, aminooxyacetic acid, nipecotic acid, di-n-propylacetate (depakin, DPA), muscimol and baclofen. After the test applied (electroshock convulsions) 50 per cent of the animals in the control group had a tonic convulsion. HB-7 and all the other agents were administered in threshold doses. GABA-ergic agents were found to have a different effect on the anticonvulsive action of HB-7 and of pentobarbital. The anticonvulsive effect of HB-7 was potentiated when it was applied in combination with baclofen and AOAA, and partially with depakin (DPA). The anticonvulsive action of pentobarbital is potentiated when it is administered in combination with DPA and AOAA. The results obtained suggest that the GABA-ergic transmission in the brain participates in the anticonvulsive effects of the barbiturates investigated (HB-7 and PB).