Early effect of ledakrin -- a nitro-derivative of acridine -- on cell membrane.

Ledakrin effect on the bioelectrical parameters of sodium ion transport (potential difference -- PD and short-circuit current -- SSC) and on Na22 transport across frog (R. esculenta) skin was studied in vitro. Ledakrin induced a biphasic action, after a phase of increase of PD, SCC and sodium flux the transport of sodium ions decreased gradually. The effect of this nitro-derivative of acridine was compared with that of Amiloride. When both these agents were given simultaneously only one phase developed, that is inhibition of sodium ion transport. In both situations there was a significant stimulation of outflux. The obtained results suggest that the external apical cell membrane of epithelial cells is the site of action of Ledakrin.