Oral glutamine attenuates surgical manipulation-induced alterations in the intestinal brush border membrane

Abstract

Background: Our earlier work has shown that surgical manipulation of the intestine results in oxidative stress and mucosal damage along with alterations in the brush border membrane (BBM). Glutamine feeding is known to offer protection against damage to mucosa under various conditions and this study looked at the effect of oral supplementation of glutamine or glutamic acid in the intestinal BBM alterations after surgical manipulation. Materials and methods: Control and rats pretreated for 7 days with 2% glutamine or glutamic acid or isonitrogenous amino acids, glycine, or alanine were subjected to surgical manipulation of the intestine. BBMs were isolated from the intestine and functional and structural alterations to these membranes were assessed and compared. Results: Surgical manipulation resulted in oxidative stress in the enterocyte BBM and these changes included a decrease in alkaline phosphatase activity and α-tocopherol content along with an increase in lipid peroxidation parameters. A decrease in glucose transport by the isolated BBM vesicles suggested functional impairment. Surgical manipulation also resulted in phospholipid degradation possibly mediated by PLA₂ and membrane protease activation. Glutamine or glutamic acid supplementation prevented these changes but not by glycine or alanine. Conclusion: This study suggests that oral glutamine or glutamic acid supplementation prior to surgery can offer protection to the intestine and this might prevent postsurgical complications.