Glutamine has a protective role on intestinal tissues via targeting NF-κB pathway in rats with sepsis

To study the protective effect of glutamine on the intestinal tissues of septic rats by regulating the nuclear factor-κB (NF-κB) pathway.

A total of 30 rats were divided into the Sham group, Model group, and Glutamine group using a random number table. The changes in the intestinal tissues in rats were observed via hematoxylin-eosin (HE) staining, and the difference in the content of serum inflammatory factor tumor necrosis factor-α (TNF-α) was detected via enzyme-linked immunosorbent assay (ELISA). Moreover, the apoptosis of the intestinal tissues was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay, and the protein expression of NF-κB in intestinal tissues was detected via Western blotting.

In the Sham group, the rats had normal activity and good mental state, and there were no evident lesions in the abdominal cavity. Compared with the rats in the Sham group, the rats in the Model group had very poor mental state and erected hair, and they trembled and barely moved. After the abdomen was opened, there were bad smell and evident bleeding in the abdominal cavity, and the cecum became black with adhesion and swelling. In the Glutamine group, the symptoms were significantly alleviated compared with the Model group. The morphological observation of the intestinal tissues revealed that in the Sham group, the intestinal villi were regularly and clearly arranged, and there was no congestion in the capillaries. Compared with the Sham group, the intestinal villi were disorderly arranged with rupture in the Model group, and the severe capillary congestion was clearly visible and accompanied by ulcer. In the Glutamine group, the intestinal villi had normal morphology and regular arrangement after treatment, the subepithelial space was significantly dilated, the capillary dilation and the congestion could be seen and the lamina propria was intact. In the Sham group, the pathological score was 0 point, and the intestinal mucosa and villi had normal structure. Compared with that in the Sham group, the pathological score of the intestinal tissues were significantly increased in the Model group (p<0.05). In the Glutamine group, the pathological score significantly declined after treatment compared with that in the Model group (p<0.05). Besides, the content of the inflammatory factor TNF-α in the intestinal tissues was the highest in the Model group (p<0.05), and it was lower in the Glutamine group than that in the Sham group (p<0.05), indicating that glutamine can effectively reduce the content of the inflammatory factor TNF-α, exerting a certain protective effect on the intestinal tissues. The number of apoptotic intestinal epithelial cells was remarkably increased in the Model group compared with that in the Sham group (p<0.05), and it was remarkably decreased in the Glutamine group compared with that in the Model group (p<0.05). The Model group had a significantly higher protein expression of NF-κB in intestinal tissues than in the Sham group and Glutamine group (p<0.05), Sham group had the lowest protein expression of NF-κB in intestinal tissues (p<0.05), and the Glutamine group had a significantly lower protein expression of NF-κB in intestinal tissues than the Model group (p<0.05).

Glutamine inhibits the protein expression of NF-κB, thereby exerting a protective effect on intestinal tissues of sepsis rats.