Effect of bicarbonate on chloride-dependent transmural potential and ATPase activity in the rectal wall of Schistocerca gregaria

Abstract

An activating effect of bicarbonate on the active transport of Cl- across the rectal wall of Schistocerca gregario has been found, as revealed by an increase of the transmural potential and short-circuit current. Acetazolamide, an inhibitor of both parameters, does not show this inhibitory effect, even at much higher concentrations, when added in the presence of bicarbonate. A Cl- or S O , anion dependent ATPase, different from the Na+, K+ ATPase, has also been Cound, which can be further stimulated by bicarbonate.