INDUCTION OF A CHLORIDE CONDUCTANCE IN GASTRIC VESICLES BY LIMITED TRYPSIN OR CHYMOTRYPSIN DIGESTION OR AGING

Transport activity of the hog gastric (H+ + K+)-ATPase system was measured either as the formation of a proton gradient using the dye probe acridine orange or as the formation of a proton diffusion potential using the cyanine dye 3,3′-diethyloxdicarbocyanine iodide in the presence of the protonophore tetrachlorosalicylanilide. The development of these gradients has been compared in K+ media in the presence of either Cl- or SO42- as the anionic species. This comparison of proton diffusion potential formation to proton gradient formation has been used to demonstrate that a Cl- conductance in this vesicular system results from limited enzymic digestion with either trypsin or α-chymotrypsin and from the ageing process itself. The possible significance of this finding is discussed. © 1979.