OBJECTIVETo study the effect of glutamine on intestinal epithelial apoptosis by examining changes regarding Bcl-2 and Bax mRNA expressions in the small intestine of young rats with endotoxemia and to explore the protective mechanism that glutamine may have.

METHODSA total of 120 18-day-old rats were randomly assigned into Endotoxemia, Glutamine-treated and Control groups (n = 40 each). The endotoxemia model was established by intraperitoneal injection of endotoxin (4 mg/kg of O55B5 Escherichia coli lipopolysaccharide). Rats in the Glutamine-treated group were intraperitoneally injected with N (2)-L-alanyl-L-glutamine (2 g/kg) along with endotoxin. Rats in the Control group were intraperitoneally injected with an equal volume of normal saline. The entire ileum was collected at 2, 4, 6, 24, and 72 hrs after injection. Bcl-2 and Bax mRNA expressions were detected by semi-quantities reverse transcriptase chain reaction.

RESULTSBcl-2 mRNA was not expressed in the Control and the Endotoxemia groups but increased in the Glutamine-treated group at each time point. Bax mRNA expression was weak in the Control group, and significantly increased in the Endotoxemia group at each time point. The Glutamine-treated group showed noticeably reduced Bax mRNA expression at 2 hrs post-injection while other time points were similar to the Control group. The ratio of Bax and Bcl-2 mRNA expression at each time point in the Endotoxemia group was significantly higher than that in the Control group while the Glutamine-treated group demonstrated significantly lower ratio of Bax and Bcl-2 mRNA expression than both.

CONCLUSIONSGlutamine treatment increased Bcl-2 mRNA expression and decreased Bax mRNA expression, as a result, the ratio of Bax and Bcl-2 mRNA expression decreased. The effects of glutamine resulted in a suppression of intestinal epithelial apoptosis and maintained the integrity of the gut barrier structure.