| Autor: |
Whang EE; Department of Surgery, UCLA School of Medicine, Los Angeles, California 90024, USA., Dunn JC, Liu CD, Newton T, Zinner MJ, McFadden DW, Ashley SW |
| Jazyk: |
angličtina |
| Zdroj: |
The Journal of surgical research [J Surg Res] 1996 Feb 01; Vol. 60 (2), pp. 303-6. |
| DOI: |
10.1006/jsre.1996.0047 |
| Abstrakt: |
Meal-stimulated colonic absorption has recently been described, but the cellular transport mechanisms mediating this response are unknown. The purpose of this study was to determine the contribution of Na+ transport pathways to colonic proabsorption. Distal colonic Thiry-Vella loops were constructed in six dogs. Absorption was measured by infusing the loops with a physiological electrolyte solution containing [14C] polyethylene glycol as the impermeant marker. In the first set of experiments, the dose dependence of amiloride-induced inhibition of basal colonic absorption was determined. In the second set of experiments the effect of amiloride, which inhibits both Na+ channels and Na+/H+ exchange in colonocytes, on meal-stimulated colonic absorption was determined. Luminal amiloride inhibited basal colonic absorption in a dose-dependent manner, with significant reductions in Na+ absorption occurring with concentrations of 10(-2)M and higher. Infusion with 10(-3)M amiloride, a concentration that did not alter basal absorption, resulted in significant reductions in postprandial water, Na+, and Cl- absorption. These results suggest that meal-stimulated colonic absorption is mediated, at last in part, by transcellular Na+ absorptive pathways. |
| Databáze: |
MEDLINE |
| Externí odkaz: |
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