过氧化物酶体增殖物激活受体γ激动剂15-脱氧前列腺素J2对小移植肝再灌注损伤的保护作用

目的 探讨过氧化物酶体增殖物激活受体γ(PPARy)激动剂15-脱氧前列腺素J2(15d-PGJ2)对小移植肝大鼠再灌注损伤的保护作用及其机制.方法 将108只SD大鼠随机分为3组:(1)15d-PGJ2预处理组;(2)15d-PGJ2+GW9662组;(3)生理盐水对照组(NS组).检测术后6、24、72 h血清丙氨酸转氨酶(ALT)和天门冬氨酸氨基转移酶(AST)水平;检测术后24 h肝组织中丙二醛(MDA)和超氧化物歧化酶(SOD)含量;检测肝组织中髓性过氧化物酶(MPO)活性以反映中性粒细胞的浸润;酶联免疫吸附试验(ELISA)检测肝组织中肿瘤坏死因子(TNF)-α水平;观察术后24h光镜下肝组织病理学变化.结果 与NS组和15d-PGJ2+GW9662组比较,15d-PGJ2预处理组术后6、24、72 h血清ALT和AST水平明显降低(P＜O.01);术后24h SOD活性明显升高而MDA含量降低,差异有统计学意义(P＜0.01);肝组织中TNF-α含量及MPO活性亦明显降低,差异有统计学意义(P＜0.01);苏木素-伊红(HE)染色显示:NS组和15d-PGJ2+GW9662组术后24 h,表现为明显的肝细胞空泡变性,肝窦扩张,炎症细胞浸润;15d-PGJ2组较其他两组肝组织损伤轻微.结论 PPARγ激动剂15d-PGJ2对小移植肝术后再灌注损伤有明显的保护作用,其保护机制可能与提高机体抗氧化能力,抑制脂质过氧化及减轻炎症反应密切相关.

Abstract：

Objective To investigate the protective effect of peroxisome proliferator-activated receptor γ (PPARγ) agonist 15d-PGJ2 against reperfusion injury in small-for-size liver grafts and its probable mechanisms. Methods 108 adult male SD rats were randomly divided into three groups: ( 1 ) 15d-PGJ2 group; (2) 15d-PGJ2 + GW9662 group; (3) NS control group. Serum aspartate aminotransferase (AST) and alanine aminotransferase (ALT) levels at 6, 24 and 72 h after reperfusion and histopathological changes were analyzed, the contents of malondialdehyde (MDA) and superoxide dismutase (SOD) in liver grafts after 24 h were determined, myeloperoxidase (MPO) activity was examined to assay neutrophil infiltration into the grafts at 24 h after reperfusion, and transforming growth factor (TGF)-α levels at 24 h after reperfusion were measured by using enzyme-linked immunosorbent assay ( ELISA method). Results As compared with NS control group and 15d-PGJ2 + GW9662 group, serum AST and ALT levels were significantly reduced at 6, 24 and 72 h after reperfusion in 15d-PGJ2 group (P ＜0. 01 ). Histopathological analysis revealed apparent bulb-like degeneration, hepatic sinusoid dilation, and inflammatory cell infiltration in periportal area at 24 h in NS group and 15d-PGJ2 + GW9662 group after transplantation, while in the 15d-PGJ2 group, minimal damage was observed at 24 h after transplantation under the light microscopy, the contents of MDA were lower and SOD levels were higher than in other groups ( P ＜0. 01 ). As compared with NS group and 15d-PGJ2 + GW9662 group, TNF-α levels and MPO activity at 24 h after transplantation were also significantly decreased in 15d-PGJ2 group (P ＜ 0. 01 ). Conclusion PPARγagonist 15d-PGJ2 could ameliorate reperfusion injury in small-for-size liver grafts significantly, which was mediated in part by increasing antioxidant ability, inhibiting lipid peroxidation, and down-regulating inflammatory reaetion.