脂氧素受体激动剂BML-111减轻大鼠机械通气肺损伤

BML-111attenuated ventilator-induced lung injuryin rats

目的探讨脂氧素受体激动剂BML-111对机械通气肺损伤(VILI)的保护作用及其机制。方法 32只健康雄性SD大鼠随机均分四组,L组:VT6ml/kg;H组:VT20ml/kg;BML组:VT20ml/kg,机械通气开始时腹腔注射BML-111(1mg/kg);BOC组:VT20ml/kg,机械通气开始前30min腹腔注射叔丁氧羟基-苯丙氨酸-亮氨酸-苯丙氨酸-亮氨酸-苯丙氨酸(BOC-2,50μg/kg),机械通气开始时腹腔注射BML-111(1mg/kg)。RR均为80次/分,机械通气时间均为4h。实验结束处死大鼠,收集支气管肺泡灌洗液(BALF)和肺组织标本。观察肺组织病理学变化,Western Blot法检测肺组织中丝裂原活化蛋白激酶(MAPK)磷酸化水平、核转录因子(NF)-κB核转位。对BALF中细胞进行分类计数,检测BALF中炎症因子TNF-α、IL-1β、IL-6表达水平。结果 H、BOC组BALF中蛋白浓度和中性粒细胞计数、TNF-α、IL-1β和L-6含量明显高于L和BML组(P<0.05或P<0.01)。H、BOC组ERK、p38MAPK和JNK磷酸化水平明显高于L和BML组(P<0.05或P<0.01)。H、BOC组IKB-α表达明显低于L和BML组(P<0.05或P<0.01);H、BOC组NF-κB p65亚基从胞浆向胞核转位明显高于L和BML组(P<0.05或P<0.01)。结论 BML-111抑制MAPK的磷酸化和NF-κB信号通路激活,并可能是其减轻VILI的机制之一。

Objective To study the protective effect of BML-111 on ventilator-induced lung injury in rats.Methods Thrity two Sprague-Dawley rats were randomized into four groups averagely：group L,VT=6 ml/kg; group H,VT=20 ml/kg; group BML,VT=20 ml/kg,BML-111 （1 mg/kg,intraperitoneally） was given at the beginning of ventilation; group BOC,VT =20 ml/kg,BML-111 （1 mg/kg,intraperitoneally） was given at the beginning of mechanical ventilation,butoxycarbonyl-pheleu-phe-leu-phe （B O C-2,50 μg/kg,intraperitoneally） was given 30 min before BML-111.Respiratory rate was set at 80 bpm and I：E at 1：1.The duration of ventilation in all groups was 4 h.At the end of mechanical ventilation,animals were sacrificed by exsanguination.The right lung was clamped at the level of the mainstem bronchus for histological analysis,western blotting for determination the MAPK phosphorylation and NF-κB translocation into the nucleus.（BALF） was collected for cell count,TNF-α,IL-1β and IL-6.Results protein concentration and the neutrophil count,TNF-α,IL-1β,and IL-6 in BALF in groups H and BOC were significantly higher than those in groups L and BML（P＜0.05 or P＜0.01）.ERK,p38MAPK and JNK phosphorylation levels in groups H and BOC were significantly higher than those in groups L and BML （P＜0.05 or P＜0.01）.IKB-α expression in groups H and BOC was significantly lower than that in groups L and BML （P＜0.05 or P＜0.01）; NF-κB p65 subunit translocation from the cytoplasm to the nucleusin in groups H and BOC was significantly higher than that in groups L and BML （P ＜ 0.05 or P ＜ 0.01）.Conclusion This study indicated that BML-111 attenuated ventilator-induced lung injury via blocking MAPK and NF-κB signaling pathways probably.