Published online Feb 15, 2002. doi: 10.3748/wjg.v8.i1.168
Revised: October 16, 2001
Accepted: November 15, 2001
Published online: February 15, 2002
AIM: To investigate the mechanism underlying intestinal barrier function damage after severe trauma and the therapeutic effect of glutamine.
METHODS: Burned patients, and animal models of severe trauma replicated by hemorrhagic shock combined with endotoxin infusion and burn injury, were included in a serial experiment. Effects of oral glutamine on intestinal barrier function were observed in scalded rats. Parameters measured in these experiments were as follows: plasma levels of diamine oxidase (DAO), tumor necrosis factor (TNFα ), endotoxin (LPS), and lactate as well as D-lactate by biochemical methods, lactose/mannitol (L/M) ratio in urine by SP-3400, and pathological examination of intestinal mucosa under light microscopy.
RESULTS: Plasma DAO activity was significantly increased after injury. There was a negative correlation between plasma DAO and intestinal mucosal DAO or pHi (r = -0.93, plasma 0.80 ± 0.93, 2.83 ± 1.71, 1.14 ± 0.64, 2.36 ± 2.06 and 2.49 ± 1.67 vs intestinal 0.52 ± 0.12, 0.34 ± 0.03, 0.45 ± 0.18, 0.37 ± 0.26 and 0.41 ± 0.07; r = -0.533, plasma 0.87 ± 0.75, 1.89 ± 1.13, 1.21 ± 0.23, 3.03 ± 2.61 and 4.70 ± 1.22 vs pHi 7.03 ± 0.05, 7.05 ± 0.06, 7.14 ± 0.096, 7.20 ± 0.08 and 7.05 ± 0.07; P < 0.01-0.05). Positive correlations were found between DAO activity and plasma TNFα , LPS, lactate, L/M and D-lactate (r = 0.817, 0.842, 0.872, and 0.951; plasma DAO 0.87 ± 0.75, 1.89 ± 1.13, 1.21 ± 0.23, 3.03 ± 2.61 and 4.70 ± 1.22 vs TNFα 0.08 ± 0.02, 0.03 ± 0.25, 0.17 ± 0.09, 0.34 ± 0.15 and 0.33 ± 0.18; vs LPS 0.14 ± 0.03, 0.16 ± 0.04, 0.21 ± 0.02, 0.18 ± 0.16 and 0.37 ± 0.10; vs lactate 9.03 ± 2.19, 18.30 ± 2.56, 9.81 ± 2.83, 12.01 ± 6.83, 12.01 ± 6.84 and 43.61 ± 11.27; vs L/M 0.03 ± 0.01, 0.41 ± 0.27, 0.62 ± 0.20, 1.70 ± 0.60; r = 0.774, plasma DAO 1.25 ± 0.41, 2.17 ± 0.71, 2.29 ± 0.87, 1.23 ± 0.55 and 1.11 ± 0.47 vs D-lactate 8.37 ± 2.48, 18.25 ± 6.18, 13.96 ± 4.94, 8.93 ± 3.00 and 12.39 ± 4.94; all P < 0.01), repestively. Damage of intestinal mucosa was found by pathological examination. Intestinal barrier function was improved to a certain extent by oral glutamine in scalded rats.
CONCLUSION: Intestinal barrier function was damaged in the early stage after trauma. Plasma DAO activity, D-lactate content, intestinal pHi and urine L/M may be sensitive markers of intestinal mechanical injury, and glutamine may protect against intestinal barrier dysfunction after severe trauma.