Comparative study of nitroimidazoles on the bioelectric properties of frog skin as a membrane model

The effects of misonidazole (MISO) and two other nitroimidazoles (5-NO2 and 4,5-NO2) on the bioelectric parameters of ion transport (potential difference and short circuit current) across frog skin as a membrane model, were studied in vitro. The nitroimidazoles investigated caused structure dependent effects on the sodium transport function of the membrane. MISO induced a biphasic action following administration on the external side of the membrane: after an initial enhancement, the potential difference and short circuit current signals both decreased. The other imidazole derivatives, 5-NO2 and 4,5-NO2, showed only one phase, whether administered on the external or internal membrane surface. All the nitroimidazoles investigated decreased sodium transport after internal or external surface administration. It was found that the 4,5-NO2 imidazole derivative irreversibly decreased the bioelectric membrane parameters.