Absorption of sodium, chloride, water, and simple sugars in rat small intestine

Abstract

Absorption of sodium, chloride, and water from the whole small intestine of the rat perfused in vivo was significantly greater from 56 m[image] solutions of glucose, 3-methyglucose, or galactose than from similar solutions of mannitol, xylose, or fructose. Each solution also contained 120 m[image] sodium chloride. Chloride was absorbed in excess of sodium. Since bicarbonate accumulated in the lumen, it appeared that bicarbonate entry occurred to maintain electroneutrality. These studies confirm previous work on the stimulatory effect of active hexose transport on sodium and water absorption. The findings are best explained by an intimate involvement of sodium in the system for active hexose transport. Significant transcellular transport of sodium, chloride, and water must be accounted for by any model for hexose transport.