乌司他丁对无心跳兔供肺的保护作用

目的 研究乌司他丁(UTI)对无心跳供者(NHBD)供肺的保护作用及其作用机制.方法 选取新两兰大白兔作为NHBD供肺离体冉灌注实验的供、受者,随机将兔分为A、B、C三组,每组各5对.A组为对照组,先使供者发生失血性休克并维持30 min,然后静脉注射氯化钾使心脏停跳,行胸外心脏按压以维持循环10 min后,原位冷却供肺,并经肺动脉灌注4℃的低钾右旋糖苷(LPD)液,取出供肺并冷保存5 h,最后将供肺与受者建立NHBD供肺离体再灌汴模型,供肺冉灌注时间为90 min;B组为UTI灌注组,供肺灌注时,LPD液中加入UTI(500 000 U/kg),其余处理同A组;C组为UTI预处理组,供者在休克期间静脉注射UTI(50 000 U/kg)行预处理,其余处理同B组.再灌注后1、30、60和90 min 4个时点,监测供肺的血氧分压(PO2)和气道峰压(PAwP).再灌注结束后,计算供肺组织湿/干重量比(W/D),并制备供肺组织匀浆,采用分光光度法和硫代巴比妥酸法测定髓过氧化物酶(MPO)和丙二醛(MDA)的活性;采用逆转录聚合酶链反应检测白细胞介素-8(IL-8)和细胞问粘附分子-1(ICAM-1)mRNA的表达水平;观察供肺病理组织学的变化.结果 再灌注后1、30、60和90 min,B组和C组的PO2、PAwP以及供肺W/D与A组比较,差异均有统计学意义(P<0.05),但B组与C组间的差异无统计学意义;再灌注结束后,B组和C组供肺组织匀浆中MPO和MDA的活性均显著低于A组(P<0.05),IL-8和ICAM-1mRNA的表达水平较A组显著下降(P<0.05);C组MPO和MDA的活性低于B组(P<0.05),IL-8和ICAM-1 mRNA的表达水平较B组显著下降(P<0.05);三组供肺组织均存在不同稗度的损伤,其中A组损伤最重,C组最轻.结论 灌注液中加入大剂量的UTI对NHBD供肺具有保护作用,尤其在NHBD休克期间注射UTI预处理.这可能与UTI能清除氧自山基,抑制炎症细胞冈子的释放、抑制中性粒细胞激活从而减轻缺血再灌注损伤有关.

Protective effects of ulinastatin during non-heart-beating donors lung transplantation

Objective To investigate the protective effects of treatment with ulinastatin (UTD during rabbit non-heart-beating donors lung transplantation, and explore the possible mechanism.Methods Thirty rabbits were divided randomly into three groups: group A as control group, group B as UTI flushing group, and group C as UTI preconditioning plus flushing group.In group A donors were exsanguinated to maintain hypotension for 30 rain before intravenous injection of potassium chloride to make heart arrest.After a period of 1 h warm ischemia in situ, topical cooling was executed.Meanwhile, the donor lungs were antegradely flushed through pulmonary arteries with low-potassium-dextron (LPD) solution at 4℃.After flushing in situ, lung-heart blocks were harvested and store at 4 ℃ for another 5 h, then perfused for 90 min in isolated, ventilated, blood-perfused rabbit lung models.Pulmonary venous blood samples were collected for blood gas analysis at 1st, 30th, 60th, and 90th min after initiation of reperfusion.At the same time, PAwP was recorded respectively.Lung samples were obtained at the end of reperfusion.The pulmonary water index (W/D), tissue myeloperoxidase (MPO) activity, tissue malondialdehyde (MDA) content, and mRNA expression of IL-8 and ICAM-1 were measured.Microscopic examination of donor lungs was conducted.In group B, the same procedures were conducted as in group A except for adding UTI (500 000 U/L) to LPD solution.In group C, except that a bolus of UTI (50 000 U/kg) was given to donors intravenously during hypotension, the same procedures were conducted as in group B.Results (1) In all three groups, there were same tendencies of gradually decreasing of PO2 levels; and as compared with groups B and C, PO2 levels in group A were significantly reduced.Similar results could be observed in PAwP values, but the tendency was increasing.(2) The level of W/D, MPO activity, MDA content, and the mRNA expression of IL-8 and ICAM-1 in groups B and C were decreased as compared with group A (P<0.05).The MPO activity, MDA content, and the mRNA expression of IL-8 and ICAM-1 in group C were decreased evidently as compared with group B (P<0.05).(3) The microscopic change of donor lung tissues in group A was more severe than in groups B and C, and that in group C was lessen than in group B.Conclusions A big dose of UTI flushing pulmonary artery had a protective effect on graft function.UTI preconditioning during hypotension can further strengthen this effect, partly by decreasing the level of oxygen free radicals, the mRNA expression of IL-8 and ICAM-1 in lung tissues, and inhibiting the activation of PMN to alleviate the ischemia-reperfusion-induced inflammation.