Objective       To observe the preventive effect of pretreatment of glutamine combined with vitamin C on intestinal endotoxemia

and to investigate the mechanism in heat stroke prevention.      Methods       One-hundred-and-sixty male SD rats were randomly divided into a glutamine and vitamin C group

a glutamine group

a vitamin C group

a heat stress group

and a normal control group. A rat model of heat stroke-induced endotoxemia was built using an artificial climate chamber. At 1

3

7 and 15 d after heat stroke

the small intestine tissues and heart blood of the rats were collected after intraperitoneal anesthesia with 2% sodium pentobarbital. The levels of superoxide dismutase (SOD) and malondialdehyde (MDA) in small intestine tissues and serum endotoxin level were measured using test kits. The mRNA expression of Toll-like receptor 2 (TLR2) in small intestine mucosa was tested by RT-PCR.      Results       Compared with the normal control group

SOD level decreased

while MDA level

serum endotoxin level

and TLR2 mRNA expression increased significantly in the heat stress group (P0.05). There were no statistical differences in SOD level and MDA level between the three treatment groups and the normal control group. Compared with the normal control group

serum endotoxin level and TLR2 mRNA expression increased significantly in the glutamine group and vitamin C group (P0.05)

but had no statistical differences in the glutamine and vitamin C group. Compared with the heat stress group

SOD level increased significantly in the three treatment groups (except for the glutamine group and vitamin C group at 7 d after heat stress)

while MDA level

serum endotoxin level

and TLR2 mRNA expre-ssion decreased significantly (except for TLR2 mRNA expression in the vitamin C group at 3 d and 15 d after heat stress) (P0.05). Compared with the glutamine group and vitamin C group

SOD level was similar in the glutamine and vitamin C group

but MDA level

serum endotoxin level

and TLR2 mRNA expression decreased significantly (P0.05).      Conclusion      Glutamine combined with vitamin C can alleviate intestinal mucosa injury caused by heat stress

protect intestinal mucosa barrier function

and reduce incidence of intestinal endotoxemia effectively. Glutamine combined with vitamin C

therefore

can be used in prevention of heat stroke.