The effect of inhibitors on intestinal transfer of glucose and fluid.

1. The effect of various experimental conditions has been studied on the transfer of hexoses and fluid by everted sacs of rat small intestine.2. The existence of glucose-dependent and glucose-independent mechanisms has been confirmed; the energy for the former comes from the citric acid cycle, and for the latter from either the glycolytic or pentose cycle.3. The energy for glucose transfer against a concentration gradient can come from metabolism of glucose by some route other than the citric acid cycle, or it may come from the citric acid cycle.4. Two-stage transfer of glucose is discussed as a possible explanation of the results.