Drug antagonism and audiogenic seizures in mice

The occurrence of audiogenic seizures in mice has been used as the basis of a method for measuring the antagonism between sodium thiopentone and bemegride or leptazol. Thiopentone in doses of 8 and 16 mg./kg. protected all the mice against the occurrence of audiogenic seizures. Bemegride and leptazol were administered in doses having molecular concentrations which bore a simple relationship to the doses of thiopentone. Bemegride was four times as powerful as leptazol in antagonizing the protective effect of thiopentone, and comparison of their regression lines showed that both analeptics acted in the same way. The antagonistic effect of bemegride occurred with doses less than its normal convulsant dose, but the doses of leptazol needed to antagonize thiopentone were within the convulsant range, and it increased the severity of any audiogenic seizures.