AIM: To investigate the role of intestinal nnucosal blood flow (IMBF) and motility in the damage of intestinal mucosal barrier in rats with traumatic brain injury. METHODS: Sixty-four healthy male Wistar rats were divided randomly into two groups: traumatic brain injury (TBI) group (n = 32), rats with traumatic brain injury; and control group (n = 32), rats with sham-operation. Each group was divided into four subgroups (n = 8) as 6, 12, 24 and 48 h after operation. Intestinal motility was measured by the propulsion ratio of a semi-solid colored marker (carbon-ink). IMBF was measured with the laser-Doppler technique. Endotoxin and D-xylose levels in plasma were measured to evaluate the change of intestinal mucosal barrier function following TBI. RESULTS: The level of endotoxin was significantly higher in TBI group than in the control group at each time point (0.382 +/- 0.014 EU/mL vs 0.102 +/- 0.007 EU/mL, 0.466 +/- 0.018 EU/mL vs 0.114 +/- 0.021 EU/mL, 0.478 +/- 0.029 EU/mL vs 0.112 +/- 0.018 EU/mL and 0.412 +/- 0.036 EU/mL vs 0.108 +/- 0.011 EU/mL, P < 0.05). D-xylose concentrations in plasma in TBI group were significantly higher than in the control group (6.68 +/- 2.37 mmol/L vs 3.66 +/- 1.07 mmol/L, 8.51 +/- 2.69 mmol /L vs 3.15 +/- 0.95 mmol/L, 11.68 +/- 3.24 mmol/L vs 3.78 +/- 1.12 mmol/L and 10.23 +/- 2.83 mmol/L vs 3.34 +/- 1.23 mmol/ L, P < 0.05). The IMBF in TBI group was significantly lower than that in the control group (38.5 +/- 2.8 PU vs 45.6 +/- 4.6 PU, 25.2 +/- 3.1 PU vs 48.2 +/- 5.3 PU, 21.5 +/- 2.7 PU vs 44.9 +/- 2.8 PU, 29. 4 +/- 3.8 PU vs 46.7 +/- 3.2 PU) (P < 0.05). Significant decelerations of intestinal propulsion ratio in TBI groups were found compared with the control group (0.48% +/- 0.06% VS 0.62% +/- 0.03%, 0.37% +/- 0.05% VS 0.64% +/- 0.01%, 0.39% +/- 0.07% VS 0.63% +/- 0.05% and 0.46% +/- 0.03% VS 0.65% +/- 0.02%) (P < 0.05). CONCLUSION: The intestinal mucosal permeability is increased obviously in TBI rats. Decrease of intestinal motility and IMBF occur early in TBI, both are important pathogenic factors for stress-related damage of the intestinal mucosal barrier in TBI. (C) 2011 Baishideng. All rights reserved.