Influence of enteral nutrition on intestinal mucosal barrier function and dopamine receptors in rats with traumatic brain injury

Objective To investigate the effect of glutamine and probiotics on intestinal mucosal barrier function and expression of dopamine receptor D1 and D2 (DRD1 and DRD2) in rats with traumatic brain injury (TBI). Methods Animal model was established by Feeney free fall TBI device. Thirty rats were randomly divided into three groups: control group, glutamine group (Gln), probiotics group (PB). The ratio of lactulose and mannitol (L/M) in urine was determined by high performance liquid chromatography (HPLC). Bacterial translocation and intestinal mucosal morphology were evaluated by eosin methylene blue (EMB) culturing and hematoxylin-eosin (HE) staining, respectively. Expression of DRD1 and DRD2 in intestinal mucosal were evaluated by immunohistochemistry, real-time PCR and western blot. Results After TBI, the weight of rats in the Gln and the PB group were (184.38±11.49) g and (185.22±8.46) g, respectively. Compared with the control group, the weight loss was significantly different (t=4.408, 5.305, respectively; P<0.05). The intestinal mucosal morphology was better in the Gln and the PB group, and reduced expression of DRD1 and DRD2 and bacterial translocation were observed in these groups. The L/M in urine were (0.051±0.010) and (0.038±0.009) in the Gln and the PB group. There were significant differences (t=26.48, 29.46, respectively; P<0.05). Conclusions Enteral nutrition with glutamine and probiotics can significantly improve intestinal mucosal barrier function in rats with TBI, which may be related to expression of DRD1 and DRD2 in intestinal mucosal. Key words: Enteral nutrition; Traumatic brain injury; Intestinal mucosal barrier function; Dopamine receptor