Effect of Electroacupuncture at ST36 on the Intestinal Mucosal Mechanical Barrier and Expression of Occludin in a Rat Model of Sepsis

Abstract

Objective To observe the effect of electroacupuncture (EA) at ST36 on the intestinal mucosal mechanical barrier and expression of the tight junction (TJ) protein, occludin, in a rat model of sepsis. Methods 60 male Wistar rats were randomly divided into six groups (n=10 rats each): Control, Control+EA, CLP (caecal ligation and puncture), CLP+EA, CLP+Sham-EA, and Sham-CLP. Rats of the CLP, CLP+EA and CLP+Sham-EA groups underwent CLP modeling of sepsis; those in the Sham-CLP underwent sham surgery and those in the Control and Control+EA groups remained unoperated. Rats in the CLP+EA and Control+EA groups received verum EA at ST36 and rats in the CLP+Sham-EA groups received EA at non-traditional acupuncture points. After three days, serum D-lactate concentrations were measured and ileal mucosa was collected for haematoxylin and eosin staining, morphological observation and Chiu's scoring. The intestinal epithelial cells were observed under transmission electron microscopy (TEM), while protein expression of occludin was measured by immunohistochemistry and Western blotting. Results TJs of the Control, Sham-CLP and Control+EA groups were continuous under TEM but discontinuous in the CLP, CLP+EA and CLP+Sham-EA groups. Plasma D-lactate levels were significantly higher in the CLP, CLP+EA and CLP+Sham-EA groups compared with the Control, Sham-CLP and Control+EA groups (P<0.01). Protein expression of occludin, reflected by immunohistochemistry scores (IHS) and the results of Western blotting, were significantly reduced in the CLP, CLP+EA and CLP+Sham-EA groups when compared with the Control, Sham-CLP and Control+EA groups (P<0.01). Compared with the CLP group, the IHS and Western blotting results of the CLP+EA group were both significantly higher (P<0.05), while those of the CLP+Sham-EA group were similar to the CLP group. Conclusions Electrical stimulation at ST36 in rats with sepsis can increase protein expression of occludin, reduce serum D-lactate levels and increase permeability of the intestinal barrier.