Abstract
Ouabain exhibits a dose-dependent choleretic effect in the isolated perfused rat liver. Its uptake from the perfusate into the liver is maintained against a concentration gradient and becomes clearly saturated at higher perfusate concentrations. A low extracellular sodium concentration inhibits the rate of ouabain transfer into liver cells, resulting in a marked decrease of the maximal transport rate. Dibucaine completely abolishes the uptake of the glycoside by the isolated liver. Determination of Na-22 tracer fluxes suggests that ouabain uptake is accompanied by a net flux of sodium into the cell, which seems to be due to a cotransport of sodium with ouabain rather than to the inhibition of the sinusoidal Na+ -K+ -ATPase. Sodium introduced into the cell in this way apparently is extruded into the bile canaliculi. The increase of isotonic bile flow, which is simultaneously observed, points to a dilution of the canalicular sodium gradient by water and electrolytes through an intercellular pathway. Our results present further evidence that bile secretion is controlled by transcellular sodium movements.
Publisher
American Physiological Society
Cited by
41 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献