Effect of total colectomy on alanine transport and the expression of its transporters in the small intestine in rats

Abstract

The present study examines the effect of total colectomy on alanine absorption and the mRNA expression of alanine transporters in the small intestine in colectomized rats. Jejunal alanine absorption was measured via the in-vivo single-pass perfusion technique. Total colectomy was performed by excising the colon from the cecum to the rectum, and then, the rats were left to recover for 15 or 30 days. Sham rats did not undergo colon resection, and were left to recover for 15 or 30 days. Two weeks post-colectomy, alanine absorption in the jejunum showed a 35% decrease relative to normal rats, and a 17% decrease relative to sham. One month posttreatment, alanine absorption in the jejunum showed a 36% decrease relative to normal rats, and a 36.4% decrease relative to sham. mRNA expressions of LAT2, ASCT2, and SLc6a14 were determined in duodenal, jejunal, and ileal samples by real-time PCR with actin as the housekeeping gene. A decrease in LAT2 mRNA expression in the duodenum and the jejunum was detected in rats 30 days post-colectomy compared to sham rats. A decrease in SLc6a14 mRNA expression in the jejunum was also detected in rats 30 days post-colectomy compared to sham rats. No significant variation in ASCT2 mRNA expression was noted in rats 30 days postcolectomy. Thus, total colectomy decreases alanine absorption in the small intestine. This suggests a cross talk between the colon and the small intestine, leading the small intestine to regulate its absorptive capacity for alanine absorption.