Pathogenesis of XXXX with @entity294 . Implications for the physiology of normal ileal electrolyte absorption and secretion.

@entity1 @entity5838 @entity972 @entity3884 @entity294 @entity1372 @entity3157 @entity1391 @entity2865 @entity597
Using a triple-lumen constant perfusion system, we have studied ileal electrolyte transport in a @entity1 with @entity5838 with @entity294 and made the following observations. First, @entity2865 cannot be transported against electrochemical gradients, but can be readily absorbed or secreted down electrochemical gradients. Second, @entity2865 secretion down an electrochemical gradient can be increased by raising lumen @entity3157 concentration. Third, @entity1372 absorption does occur against electrochemical gradients and is associated with @entity3884 ion secretion. Fourth, electrical potential difference (PD) between lumen and blood is near zero when lumen @entity1372 concentration is 140 mEq/liter. Fifth, a normal @entity1372 diffusion potential is present. Sixth, @entity972 is transported passively in response to electrochemical gradients. The ileal electrolyte transport disorder of @entity5838 with @entity294 can be simulated exactly in normal subjects perfused with a solution in which @entity2865 is replaced with poorly absorbable @entity597 and @entity1391 . These results can be explained by postulating a single defect in the double ion exchange model ( @entity1372 - @entity3884 , @entity2865 - @entity3157 ) previously proposed for normal ileal transport: i.e., normal @entity1372 - @entity3884 exchange, but a @entity2865 - @entity3157 exchange that is incapable of transporting @entity2865 against an electrochemical gradient, yet continues to transport anions passively. In contrast, the results appear incompatible with the concept of ileal electrogenic @entity1372 transport.
