胆红素在大鼠肺脏缺血再灌注损伤中的抗凋亡作用

目的探讨胆红素对实验性大鼠肺缺血再灌注损伤的抗凋亡作用。方法60只健康Wistar大鼠随机分为3组:手术对照(C)组,缺血再灌注(IR)组,胆红素干预(B)组。每组分别于夹闭缺血的45min,再灌注后30、60、120min4个时点处死大鼠,取血浆和右肺中叶,观察肺组织病理形态变化,测定肺组织干重/湿重(D/W),TUNEL法测定肺组织中细胞凋亡指数(AI)。结果①肺组织D/W:经缺血和再灌注后,IR组和B组的肺组织D/W都呈进行性下降(P<0.01);B组下降幅度明显小于IR组(P<0.05);②肺组织细胞AI的变化:与IR组相比,B组相同时点的肺组织细胞凋亡数显著减少(P<0.05);③肺组织病理变化:缺血再灌注后IR组肺组织损伤进行性加重,B组肺组织充血、水肿、炎性细胞浸润较IR组减轻。结论胆红素对于实验性大鼠肺脏缺血再灌注损伤具有一定的保护作用,其作用机制可能与抗细胞凋亡有关。

The anti-apoptotic role of bilirubin in ischemia-reperfusion injury of rat lungs

Objective To study the anti-apoptotic role of bilirubin in ischemia- reperfusion injury of rat lungs. Methods Sixty healthy Wistar rats were randomized to receive surgical procedure (control group, group C), ischemia-reperfusion (group IR) and bilirubin intervention (group B). Rats from each group were sacrificed in fives at one of four time spots (45 min ischemia, 30, 60 and 120 min reperfusion), harvested for plasma samples and middle lobes of the right lung, and detected for dry-to-wet (D/W) weight ratio of lung tissue, histology, and apoptotic cells in the right middle lobe as measured by apoptosis index (AI) using terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL). Results ①After ischemia and reperfusion, the D/W ratio showed progressive decrease in groups IR and B (P<0.01), but the change was much less in group B than in group IR (P<0.05). ②At all time spots, the AI in group B was obviously lower than in group IR group (P<0.05). ③Histological evaluation: while ischemia-reperfusion resulted in progressive deterioration of lung injury in group IR, group B was less affected in terms of congestion, edema and pro-inflammatory infiltration. Conclusion Bilirubin intervention appeared protective against lung injury caused by experimental ischemia-reperfusion in rats, which may be attributed to its anti-apoptotic effect.