Protective effect of compound preconditioning on small intestine from ischemiaª²reperfusion injury in rats

    ZHOU Shuiª²Sheng, GAO Hui

    Department of Surgery, Xianning Medical College, Xianning 437100, China

    ¡¾Abstract¡¿ AIM: To investigate the protective effect of compound precondition(ischemicª²preconditioning under the mild hypothermia MHIP) on small intestine from ischemiaª²reperfusion(I/R) injury in rats and its mechanism. METHODS: Thirtyª²two rats were randomized into 4 groups (8 in each group): Sham operated group (sham), ischemiaª²reperfusion (I/R) group, ischemicª²preconditioning (IP) group, mild hypothermia ischemicª²preconditioning (MHIP) group.The wet/dry ratio, Ca2+ª²Mg2+ª²ATPase in intestine tissue, the LDH, malondialdehyde (MDA), and activities of superoxide dismutase (SOD) and total antioxidase (TAX) in blood were compared. ultrastructure, Bclª²2 and Bax expression in intestinal mucosa tissue were observed. RESULTS: After I/R, the tissue wet/dry ratio, LDH and MDA were significantly elevated(P<0.01). Ca2+ª²Mg2+ª²ATPase, SOD, TAX declined obviously; the optic density of Bclª²2 and Bax proteins increased significantly(P<0.01). The tissue wet/dry ratio, LDH, MDA and the optic density of Bax protein were significantly lower in IP group than in I/R group, and in MHIP group than in IP group. The content of Ca2+ª²Mg2+ª²ATPase. SOD, TAX and the optic density of Bclª²2 protein were significantly higher in IP group than in I/R group (P<0.01), and in MHIP group than in IP group (P<0.05).CONCLUSION: MHIP can protect intestine against I/R injury in rats, which may be related to enhancing oxidationª²resistance of intestine, inhibiting lipid peroxidation, upregulating the protein expression of bclª²2 genes and downregulating the protein expression of bax genes and reducing myocyte apoptosis. ......