高压氧预处理对大鼠小肠缺血再灌注损伤的保护作用

The protective effect of hyperbaric oxygen preconditioning on intestinal ischemia-reperfusion injury in rats

目的:研究高压氧预处理对大鼠小肠缺血再灌注损伤(IRI)的保护作用。方法:30只雄性SD大鼠随机分为假手术组( n=10)、缺血再灌注组(I/R组, n=10)和高压氧预处理组(HBO组, n=10)。HBO组实施高压氧预处理,每日2次,每次60 min,连续暴露2 d,末次暴露结束后24 h行肠IRI,缺血45 min再灌注60 min。处死大鼠,取空肠组织用于石蜡切片,HE染色观察组织病理学改变;组织匀浆法测定丙二醛(MDA)含量和髓过氧化物酶(MPO)活性;TUNEL法测定肠上皮细胞凋亡情况。 结果:HE染色结果显示I/R组大鼠空肠肠绒毛剥脱明显,大量炎性细胞浸润,上皮层和固有层大量分离;高压氧预处理后肠黏膜损伤显著减轻,肠绒毛结构较完整,仅有少量炎性细胞浸润。与假手术组对比,IRI组大鼠肠组织MDA含量[(1.46±0.14) nmol/mg protein]和MPO活性[(0.190±0.018) U/g tissue]均显著增高,而高压氧预处理能明显降低大鼠肠组织MDA含量[(0.84±0.09) nmol/mg protein]和MPO活性[(0.097±0.011) U/g tissue],差异有统计学意义( P<0.05)。此外,高压氧预处理组TUNEL阳性细胞数明显少于缺血再灌注组( P<0.01)。 结论:高压氧预处理对小肠IRI具有保护作用,其机制可能与其抗氧化、抗炎、抗凋亡作用有关。

Objective To investigate the protective effect of hyperbaric oxygen preconditioning on intestinal ischemia-reperfusion injury(IRI)in rats.Methods Thirty male SD rats were randomly divided into sham-operated group(n=10),ischemia-reperfusion injury group(I/R,n=10)and hyperbaric oxygen preconditioning group(HBO,n=10).In the HBO group,the rats were exposed to hyperbaric oxygen for 60 min every time,twice a day for two days.Twenty-four hours after the last exposure,the rats were undergone IRI(ischemia 45 min/reperfusion 60 min).The jejunum was taken out for paraffin section.HE staining was used to detect the histopathological change.The malondialdehyde(MDA)content and myeloperoxidase(MPO)activity in the jejunum were measured with the tissue homogenization.Apoptosis in intestinal epithelium was determined with terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling technique(TUNEL).Results In I/R group,HE staining showed obvious exfoliation of jejunum villus,significant inflammatory cellular infiltration,and massive separation of epithelial layer and lamina propria.In HBO group,after HBO preconditioning,the damage of intestinal mucosa was significantly reduced,and the structure of villus was intact with only a small amount of inflammatory cellular infiltration.Compared with the sham-operated group,the MDA content(1.46±0.14 nmol/mg protein)and MPO activity(0.190±0.018 U/g tissue)in the jejunum of the I/R group were significantly higher after IRI.HBO preconditioning could significantly reduce the MDA content(0.84±0.09 nmol/mg protein)and MPO activity(0.097±0.011 U/g tissue),as compared with I/R group.All those differences were statistically significant(P<0.05).In addition,compared with I/R group,the number of positive cells of HBO group was significantly lower as determined by TUNEL(P<0.01).Conclusion The HBO preconditioning had a protective effect on intestinal IRI,and the mechanism may be related to anti-oxidation,anti-inflammation,and anti-apoptosis.