Effect of inhibitors on chloride-dependent transmural potential in the rectal wall of Schistocerca gregaria

Abstract

Previous experiments in vitro revealed a transmural potential difference (PD) and a shortcircuit current (IX) across the rectal wall of Schistocerca yregariu. which were dependent on chloride ions in lumen. The present report shows that anoxia. dinitrophenol and cyanide inhibit DP and IX. proving that the required energy derives from oxidative metabolism. Acetazolamide also inhibits DP and Isc. Ouabain. when in haemocoele, has also an inhibitory effect, not ascribable to a Na’-K’ pump blocking action. It is suggested that HCO; plays an important rBle in the active transport of Cl- from lumen to haemocoele and that ouabain may in some way inhibit chloride pumping.