Short-circuit current related to active transport of chloride in frog cornea: effects of furosemide and ethacrynic acid

Active transport of Cl⁻ accounts for 90% of the short-circuit current (s.c.c.) in the isolated frog cornea. 1·10⁻⁵ M furosemide produced a 50% reversible inhibition of this s.c.c. 1·10⁻⁴ M ethacrynic acid reduced the corneal s.c.c. to 32% of the control. In the isolated frog skin epithelium furosemide had no effect on the s.c. at a concentration of 1·10⁻⁴ M and a small stimulation at a concentration of 1·10⁻³ M. The furosemide inhibitory effects seems to be specific for Cl⁻, as it also inhibits Cl⁻ transport in the ascending limb of the loop of Henle (Burg, M.B. (1972) Proc. 5th Int. Congr. Nephrol., p. 50, Abstr.).