Effects of postoperative periods on glucose absorption and electrolyte secretion in the intestinal loop of sheep

This study was designed to determine the effect of postoperative periods on intestinal absorptive and secretory functions in the jejunal Thiry-Vella loop of sheep. The lumen was perfused with isotonic saline solution for 120 min at 1 ml/min. The secretory function was assessed by measuring the secretory response of water and electrolytes to PGE2 which was applied intraluminally at 100 microM during the second 30 min period. To measure glucose absorption, 10 mM isotonic glucose solution with its osmolality adjusted by adding NaCl was perfused. Measurements were taken at 1 week intervals for 3 months after surgery. Under basal conditions, water, sodium and chloride were absorbed, while potassium and bicarbonate were secreted. These net basal movements did not change throughout the 3 month period. PGE2 reversed the net absorptions of water, sodium and chloride to the net secretions, and significantly augmented bicarbonate secretion. Potassium secretion was not changed significantly by PGE2. These responses to PGE2 were not affected by the postoperative periods. Glucose absorption decreased gradually for 8 weeks after construction of the jejunal loop with a significant negative correlation to the postoperative period, and subsequently remained at a steady state of nearly 65% of the first week. This decrease in glucose absorption was prevented by regular perfusion of glucose. The results show that the Thiry-Vella loop of the ovine jejunum can be used to measure secretory function for 3 months or more after its construction, but it is essential to regularly perfuse the loop with glucose solution when this loop is used for absorptive experiments of glucose for a long time.