Antioxidative effects of all-trans retinotic acid on the intestinal ischemia reperfusion / 中华消化外科杂志

ABSTRACT

Objective To investigate the antioxidative effects of all-trans retinoic acid (ATRA) on the intestinal ischemia reperfusion.Methods Thirty-two male SD rats were randomly divided into the sham operation group,occlusion group,dimethyl sulfoxide (DMSO) group and the ATRA group according to the random number table.There were 8 rats in each group.Rat models of intestinal ischemia reperfusion were established by clamping the superior mesenteric arteries for 60 minutes,and then restore the blood flow for 120 minutes.Superior mesenteric arteries were only separated without clamping in the sham operation group.Rats in the ATRA group received ATRA pretreatment through intragastric infusion at the dosage of 15 μg/g for 5 days,and then ATRA pretreatment at 6 hours before operation.Rats in the DMSO group received intragastric infusion of DMSO at the same dosage.The concentration of ATRA at 5 hours before operation was detected by high performance liquid chromatography.The pathomorphological changes of the ileal mucosa were detected by hematoxylin-eosin staining,and the Chiu's scores on the ileal mucosa were evaluated.The serum content of diamine oxidase (DAO),tissue level of malonaldehyde (MDA) and activity of superoxide dismutase (SOD) were detected by colorimetry.Protein expression of manganese superoxide dismutase (MnSOD) in the ileal tissues was detected by Western blot.All data were analyzed using the analysis of variance or LSD-t test.Results The concentrations of ATRA in the ATRA group was (827 ±276) μg/L,which was significantly higher than (48 ± 12) μg/L of the sham operation group,(55 ± 15) μg/L of the occlusion group and (63 ± 20) μg/L of the DMSO group (t =11.242,11.138,11.013,P ＜ 0.05).The morphology of the ileal mucosa was normal in the sham operation group,while the ileal mucosa was severely damaged in the occlusion group and the DMSO group.The injury of the ileal mucosa in the ATRA group was slight.The Chiu's scores of the occlusion group,DMSO group and the ATRA group were 3.83 ±0.77,3.92 ± 0.87 and 2.42 ± 0.75,which were significantly higher than 0.37 ± 0.28 of the sham operation group (t =9.803,10.040,5.793,P ＜0.05).The Chiu's scores of the ATRA group was significantly lower than that of the occlusion group and the DMSO group (t =4.009,4.247,P ＜ 0.05).The DAO levels of the occlusion group,DMSO group and the ATRA group were (26.3 ±4.4)U/L,(25.1 ± 4.3)U/L and (20.8 ±3.8)U/L,which were significantly higher than (14.2 ± 1.9) U/L of the sham operation group (t =6.493,5.835,3.534,P ＜ 0.05).The level of DAO of the ATRA group was significantly lower than that of the occlusion group and the DMSO group (t =2.959,2.301,P ＜0.05).The levels of MDA of the occlusion group,DMSO group and the ATRA group were (16.9 ± 4.0) μmol/g,(16.0 ± 3.5) μmol/g and (11.3 ± 3.1) μmol/g,which were significantly higher than (5.4 ± 1.0) μmol/g of the sham operation group (t =7.397,6.821,3.821,P ＜ 0.05).The level of MDA of the ATRA group was signifcantly lower than that of the occlusion group and the DMSO group (t =3.575,3.000,P ＜ 0.05).The SOD activity of the occlusion group,DMSO group and the ATRA group were (108 ±22) U/mg,(98 ± 19) U/mg and (181 ± 38)U/mg,which were significantly lower than (243 ± 37)U/mg of the sham operation group (t =8.939,9.647,4.106,P ＜ 0.05).The SOD activity of the ATRA group was significantly higher than that of the occlusion group and the DMSO group (t =4.833,5.541,P ＜ 0.05).The relative protein expressions of the MnSOD of the occlusion group and the DMSO group were 0.36 ± 0.08 and 0.28 ± 0.07,which were significantly lower than 0.93 ± 0.13 of the sham operation group (t =8.972,10.101,P ＜ 0.05).The relative protein expression of the MnSOD of the ATRA group was 0.80 ± 0.19,which was significantly higher than that of the occlusion group and the DMSO group (t =6.948,8.077,P ＜ 0.05),while it was not significantly different from that of the sham operation group (t =2.024,P ＞ 0.05).Conclusion Through up-regulating the expression of MnSOD and improving the antioxidative capacity of tissue,ATRA pretreatment can attenuate intestinal ischemia and reperfusion injury.