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目的:探讨缺氧诱导因子-1α(hypoxia inducible factor-1 alpha,HIF-1α)对鼠肺缺血再灌注损伤是否具有保护作用及可能的机制。方法:选择体重250～350 g的健康雄性SD大鼠72只,随机分为3组,缺血再灌注组、二甲基乙二酰基甘氨酸(DMOG)组、假手术组,每组24只。缺血再灌注组:建立左肺缺血和再灌注动物模型:在肺充气状态下用无损伤动脉钳夹闭左侧肺门,阻断45 min后松开动脉夹,形成再灌注;DMOG组:在缺血和再灌注动物模型建立前24 h进行腹腔内注射DMOG 20μg/g;假手术组:仅行左侧开胸,不行缺血再灌注处理。缺血再灌注组与DMOG组于再灌注1 h、3 h、6 h、12h后颈动脉放血处死大鼠,假手术组于开胸后1 h、3 h、6 h、12 h颈动脉放血处死大鼠,取左肺上半部制成匀浆,硫代巴比妥酸比色法检测丙二醛含量、黄嘌呤氧化酶法检测超氧化物歧化酶活力,酶联免疫吸附法测定匀浆内白细胞介素-8含量,下半部通过免疫组化法行HIF-1α蛋白表达的观察与光镜下苏木素伊红(HE)染色后肺组织病理学改变的观察。结果:HIF-1α蛋白主要表达于肺泡上皮细胞的胞核或胞浆,与假手术组比较,缺血再灌注组、DMOG组各时间点HIF-1α蛋白的表达增强,DMOG组较缺血再灌注组各时间点HIF-1α蛋白的表达增强;缺血再灌注组、DMOG组在再灌注后3 h、6 h、12 h(缺血再灌注组12 h除外)较1 h HIF-1α蛋白的表达增强,差异有统计学意义(P<0.05或P<0.01)。与假手术组比较,缺血再灌注组、DMOG组各时间点白细胞介素-8(除DMOG组1 h外)、丙二醛含量均升高,而超氧化物歧化酶活力降低;DMOG组较缺血再灌注组各时间点白细胞介素-8、丙二醛含量均降低,而超氧化物歧化酶活力升高;缺血再灌注组、DMOG组在再灌注后3 h、6 h、12 h较1 h:白细胞介素-8含量(除DMOG组3 h外)升高,丙二醛含量(除缺血再灌注组、DMOG组12 h外)升高,超氧化物歧化酶活力降低,差异均有统计学意义(P<0.05或P<0.01)。光镜下DMOG组肺组织炎性渗出较缺血再灌注组减轻。结论:HIF-1α通过降低肺组织中丙二醛、白细胞介素-8含量,增强肺组织中超氧化物歧化酶活力,减轻肺内毛细血管充血及炎性细胞浸润,对大鼠肺缺血与再灌注损伤发挥保护作用。
Objective: To investigate whether hypoxia inducible factor-1α (HIF-1α) has a protective effect on lung ischemia-reperfusion injury in rats and its possible mechanism. Methods: Seventy-two healthy male Sprague-Dawley rats weighing 250-350 g were randomly divided into three groups: ischemia-reperfusion group, DMEG group and sham operation group, 24 rats in each group. Ischemia / reperfusion group: The animal model of left lung ischemia and reperfusion was established: The left hilar was occluded with the intact arterial forceps and the artery clips were released after 45 min of occlusion to establish reperfusion; : Intraperitoneal injection of DMOG 20 μg / g 24 h before establishment of the animal model of ischemia and reperfusion; sham operation group: left thoracotomy only, no ischemia-reperfusion treatment. Rats in ischemia-reperfusion group and DMOG group were sacrificed by carotid artery in 1, 3, 6, 12 hours after reperfusion. Rats in sham operation group were given carotid bled at 1 h, 3 h, 6 h and 12 h after thoracotomy The rats were sacrificed, the upper half of the left lung was taken for homogenization, the thiobarbituric acid colorimetric method was used to detect the content of malondialdehyde, the activity of superoxide dismutase was determined by xanthine oxidase method, the enzyme-linked immunosorbent assay The content of interleukin-8 in the plasma and the expression of HIF-1α in the lower part of the lung were detected by immunohistochemistry and the histopathological changes of the lung tissue were observed under the light microscope by hematoxylin and eosin staining. Results: HIF-1αprotein was mainly expressed in the nucleus or cytoplasm of alveolar epithelial cells. Compared with the sham operation group, the expression of HIF-1αprotein in the ischemia-reperfusion group and the DMOG group increased at each time point, The expression of HIF-1αprotein increased at each time point in perfusion group. Compared with 1 h HIP-1αprotein in ischemia / reperfusion group and DMOG group at 3 h, 6 h and 12 h after ischemia reperfusion (except 12 h) The difference was statistically significant (P <0.05 or P <0.01). Compared with the sham-operation group, IL-8 and DMOG increased IL-8 and MDA levels at each time point in DMOG group Compared with ischemia-reperfusion group, IL-8 and MDA content decreased and SOD activity increased at each time point. In ischemia and reperfusion group and DMOG group, the levels of interleukin-8, 12 h compared with 1 h: interleukin-8 content (except DMOG group 3 h) increased, malondialdehyde content (except ischemia-reperfusion group, DMOG group 12 h) increased, superoxide dismutase activity Decreased, the differences were statistically significant (P <0.05 or P <0.01). Under light microscope, inflammatory exudation of lung tissue in DMOG group was less than that in ischemia-reperfusion group. CONCLUSION: HIF-1α can inhibit the pulmonary ischemia-reperfusion injury by decreasing the content of malondialdehyde and interleukin-8 in lung tissue, increasing the activity of superoxide dismutase in lung tissue, reducing capillary congestion and inflammatory cell infiltration in the lung Reperfusion injury play a protective role.