Effects of intestinal mucosal blood flow and motility on intestinal mucosa

AIM:To investigate the role of intestinal mucosal 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.