Protective effect of glutamine on neonatal rats with necrotizing enterocolitis

Objective To investigate the nutrient effects of glutamine (Gln) on small intestinal repair in neonatal rats after necrotizing enterocolitis ( NEC). Methods Thirty 1 day neonatal rats were devided into three groups, (A) control group. (B) NEC and non-intervention. (C) NEC and glutamine (Gln)-group(2.0g/kg.d). NEC model was established as following method: neonatal rats were put into 100% carbon dioxide for 5 min and then 100% oxygen for 5 min before returned to their mothers. This was done once daily for 3 days. On the 4~ th day, all the subjects were sacrificed. Intestinal tissue located at the boundary of ileum and cecum was obtained to do pathological study. Morphological changes were measured under a light microscope, expression of proliferating cell nuclear antigen (PCNA) as an index of cell proliferation was observed using immunohistochemical staining and image analysis, expression of apoptosis was studied using TUNEL staining and image analysis. Results In group B, the histological lesions was different, and was graded 3 point. In group C, some intestinal mucous was normal, and some stratum submucosum and lamina propria was separate, or stratum submucosum and basement layer was dropsy, and was graded 1 point. The number of PCNA in group B lower than group A(P0.01); The number of PCNA in group C higher than group B(P0.05).The number of apoptosis in group B higher than group A(P0.01); The number of apoptosis in group C lower than group B(P0.05). Conclusions NEC can made neonate rat intestinal mucosa damage, step down proliferation of intestinal mucous, and to increase number of apoptosis in intestinal mucous. Oral glutamine could improve the proliferation of crypt cell, reduce apoptosis of intestinal mucosa, and promote repair of intestinal mucosa after NEC.