20 MECHANISMS OF TRANSPORT OF SODIUM AND CHLORIDE AND THE EFFECTS OF INFLAMMATION IN THE HUMAN INFANT COLON

A major function of the colon is the conservation of salt and water and we have previously shown (Jenkins et al GUT 27; 1283, 1986) that in the human infant it plays a major homeostatic role. Colitis may therefore assume greater importance than in later life. We have carried out a detailed study of transport in normal and inflammed isolated human infant colon using an Ussing Chamber and a voltage clamp procedure. Stripped colonic mucosa histologically normal n=6 pairs and inflammed from patients with non-clostridial Hirschsprung's enterocolitis, n=5 pairs was mounted and bathed in Krebs2 solution. Under short-circuit conditions Na+ (3.45±1.53 umol/hr/cm mean ± ISD) and Cl−(0.63±3.61) were absorbed and a residual ion flux consistent with HCO3− secretion approximated Cl− absorption. Short circuit current (ISC) (3.8±0.28) was very similar to net Na+ movement and was markedly reduced by mucosal 10−4 M amiloride (0.61±0.7 p