Chloride compartments of the frog lens and chloride permeabilities of its isolated surfaces

Total Cl content and exchangeable Cl pools of isolated bull frog lens and Cl permeabilities of its isolated anterior and posterior surfaces were determined. Cl content was 2.81 microEq, corresponding to a cellular concentration of 13.3 mM. After 18 hr. incubation Cl content increased to 3.84 microEq. Three Cl compartments were found: a fast compartment (t1/2 = 130 min.), probably extracellular; a slow compartment (+ 1/2 = 160 min.), probably intracellular; and a bound fraction (24% of the total Cl). 36Cl efflux across anterior and posterior lens surfaces was similar. However, when a correction for the asymmetrical electrical potential difference was made, the permeability of the posterior side, 46.9 x 10(-7) cm./sec., was nearly twice the permeability of the anterior side, 27.6 x 10(-7) cm./sec. The Cl movement and distribution seem to obey passive forces. Iodoaceta increased both total Cl and exhangeable Cl but had little effect on the rate of Cl exchange. Total Cl gain by lenses incubated at 2 degrees C was similar to the control. However, the exchangeable Cl pools and the rate of exchange were significantly diminished.