Effect of calcium antagonist compound nisoldipine on transepithelial electrical parameters in the isolated frog cornea.

The new calcium antagonist, nisoldipine, inhibited short circuit current and transcorneal potential difference in the isolated frog cornea (a chloride transporting epithelium). Transepithelial resistance increased. The effects of nisoldipine were dose-dependent. Nisoldipine did not change the stimulation of short circuit current induced by epinephrine. Intracellular membrane potential across both the apical and basolateral cell membrane were decreased by nisoldipine. The data indicate that intracellular calcium seemed to modulate chloride transport of the cornea by changing cell membrane permeability.