Expression of glucose transporters in the small intestine pre and post-colectomy in adult rats

Abstract

Themainfunctionofthecoloniswaterandelectrolyteabsorption.Totalcolectomyeliminatesthis colonic function and may alter the absorptive capacity of the small intestine for nutrients. We have previously examined the effect of total colectomy on glucose absorption by the In-Vivo single pass perfusion technique in the jejunum in sham and colectomized adult rats2 weeks and 1 month post-colectomy. Glucose absorption increased 2 weeks post-colectomybut returned to normal 1 month post-colectomy. In order to investigate the factors thatregulate the changes in glucose absorption in the small intestine post-colectomy, and toexamine whether a functional adaptation for glucose transport occurs then in the smallintestine, we have determined the effect of total colectomy on the expression of glucosetransporters in the small intestine of normal, sham and colectomized Sprague-Dawley ratsthat were allowed to recover for 2 weeks or 1 month. Total colectomy with ileo-rectalanastomosis was performed on anesthetized rats (n=5). Sham rats (n=5) were identicallyhandled without colon resection. mRNA expressions of SGLT1 and GLUT5 were determinedin duodenal, jejunal, and ileal samples by real-time PCR with actin as the housekeepinggene. A significant increase in SGLT1 (70.9±14 vs 38±7.2 in normal/sham) and GLUT5(129±21 vs 52±13 in normal/sham) mRNAs were detected in the jejunum 2 weeks post-colectomy (p<0.01). However, SGLT1 and GLUT5 levels returned to normal 1 month post-colectomy. SGLT1 and GLUT5 mRNAs significantly increased in the ileum 2 weeks and 1month post-colectomy (p<0.01). GLUT5 mRNA significantly increased in the duodenum 2weeks post-colectomy (129±26 vs 45.88±12.5 in normal/sham, p<0.01) and returned tonormal 1 month post-colectomy. No significant variation in SGLT1 or GLUT5 mRNA wasnoted in sham animals. Our results show that a functional adaptation occurs in the smallintestine in total colectomy. The duodenum, jejunum, and ileum can modulate their absorpt-ive capacity by up-reg.