CHOLESTEROL ABSORPTION AND SYNTHESIS AFTER AUTOTRANSPLANTATION OF PORCINE ILEUM

Background. Cholesterol, long-chain fatty acids, and fat-soluble vitam ins are absorbed mainly in the upper small intestine and bile acids in the terminal ileum. This study determined the consequences of ileal a utotransplantation on cholesterol metabolism plasma fatty acids, and v itamin A absorption. Methods. Plasma lipids, cholesterol precursors, p lant sterols cholestanol, fatty acids, vitamin A absorption, and anima l growth were studied for 3 months after transection (n = 5), jejunal (50%) resection (n = 7), jejunal (50%) resection combined with orthoto pic ileal autotransplantation (n = 7), and enterectomy (n = 7). Result s. Cholesterol precursor to cholesterol proportions in plasma (reflect cholesterol synthesis) remained unchanged after transection and jejun al resection. The plasma plant sterol proportions (reflect cholesterol absorption) and retinol absorption increased after transection and le ss significantly after jejunal resection, whereas plasma fatty acid co mpositions were virtually unchanged. Transplantation of ileum and ente rectomy amended zip to sixfold the precursor proportions (p < 0.05 ver sus transection or jejunal resection) and impaired body weight gain. T he plant sterol proportions, vitamin A absorption, and plasma choleste rol levels, respectively, were significantly (p < 0.05) decreased afte r transplantation when compared with those of the transected control g roup but remained markedly higher than those in the enterectomized gro up. Linoleic acid was signficantly (p < 0.05 versus transection) decre ased, whereas monoenoic fatty acids and eicosatrienoic acid were incre ased (p < 0.05 versus jejunal resection) in plasma lipids. Conclusions . These results indicate that autotransplantation of ileum in pigs tha t have undergone jejunectomy impairs sterol, essential fatty acid, and vitamin A absorption so that plasma cholesterol levels decrease despi te markedly increased cholesterol synthesis and that these changes cle arly exceed those found after jejunal resection alone.