ILEUM BRUSH-BORDER ALKALINE-PHOSPHATASE ACTIVITY IN AN EXPERIMENTAL-MODEL OF CHRONIC-ALCOHOLISM AFTER SMALL-BOWEL PROXIMAL RESECTION IN THERAT

Literature reports that chronically ingested ethanol induces changes i n the morphology of the small bowel mucous membranes. It has a topical toxic effect on the epithelium of the proximal jejunum and a bloodbor ne effect on the epithelium of the ileum because its absorption is alm ost complete in the stomach, duodenum and proximal jejunum. In additio n there are also reports showing stimulation of enterocyte proliferati on after segmental intestine resection. In this report we compare a gr oup of rats submitted to resection of the proximal jejunum and fed a l iquid diet containing 35% of the total calories intake as ethanol for four weeks to its control pair-fed group. In both groups we studied th e mucosal alkaline phosphatase (APase) activity by histochemical as we ll as biochemical methods. We found a decreased APase activity in the homogenate of the intestinal mucous membrane in the alcoholic group an d a reduced enzymatic activity in the brush border of the ileum entero cytes, as demonstrated by histochemical qualitative and densitometric assays. The result suggests that this change in APase activity of the brush border may represent enterocyte immaturity induced by long-stand ing ethanol intake in the remnant ileum after proximal resection.