[Effects of imidazole, papaverine and theophylline on the picrotoxin convulsion-seizure threshold. The correlation with gamma-aminobutyric acid (GABA) and diazepam].

The author carried out studies on male white rats and examined the effect of imidazol, papaverine and theophyline (drugs affecting the activity of phosphodiesterase), singly or in correlation with GAMA and diazepam on picrotoxic seizure threshold (PSAT). He found that imidazol had various effects on PSAT in accordance with the interval of application and antagonized the effects of GAMA. Papaverine in low doses was ineffective, but in higher doses lowered PSAT; it antagonized the effect of GAMA, elevating the threshold. Papaverine in combination with CAMF antagonized the effect of GAMA, elevating the threshold. Theophyline lowered PSAT; it did not influence the effects of the combined application of GAMA and DIA. He thinks that the obtained changes in PSAT could partly be connected with the mediating influence of imidazol, papaverine and phe theophyline on cerebral phosphodiesterase both after their single application and after examination of their correlations with GAMA or DIA, used singly or in comibination, and partly with their own pharmacologic action.