摘要
目的:研究大鼠肺组织在不同潮气量机械通气的情况下小窝蛋白-1( Cav-1)及p38 MAPK表达的变化。方法56只雄性健康成年SD大鼠,体质量220-330 g,随机均分为7组,自主呼吸对照组( A组):仅做气管切开;不同通气时间保护性机械通气组( B1组和B2组):潮气量( VT )为6 mL/kg,呼吸频率( RR)为60次/min,B1组通气1 h,B2组通气2 h;不同通气时间大潮气量组( C1组和C2组);不同时间大潮气量+SB203580组( D1组和D2组)。 C和D组VT为30 mL/kg,RR为40次/min,C1和D1组通气1 h,C2和D2组通气2 h。机械通气前30 min D组大鼠给予注射SB203580溶液,实验中7组大鼠均给予动脉血气和血流动力学监测。 A组行气管切开即刻处死,剩余各组大鼠于预定时间机械通气结束时处死,光镜下观察肺病理改变,免疫组织化学染色法检测肺组织中Cav -1、p38 MAPK及AP-1蛋白的表达,测定Cav -1、MKK3、p38 MAPK mRNA表达,测定髓过氧化物酶(MPO)活性及肺湿干质量比值(W/D),ELISA法测定支气管肺泡灌洗液( BALF)中总蛋白及IL-6含量。结果与A组比较,C组Cav-1、p38 MAPK蛋白及Cav-1、p38 MAPK、MKK3 mRNA表达上调,W/D比值、MPO、总蛋白浓度、IL-6含量升高,蛋白激酶(AP)-1蛋白表达下降(P<0.05)。与B组比较,C组Cav-1、p38 MAPK蛋白及p38 MAPK、Cav-1、MKK3 mRNA表达上调,W/D比值、MPO、总蛋白浓度、IL-6含量升高,AP-1蛋白表达水平下降( P<0畅05)。与C组比较,D组p38 MAPK蛋白及p38 MAPK、MKK3 mRNA表达下降,Cav-1、AP-1蛋白及Cav-1 mRNA表达上升,W/D比值、MPO、总蛋白浓度、IL-6含量升高(P<0.05)。结论 Cav-1及其p38 MAPK信号链在机械通气中表达的上调,参与了机械通气相关性肺损伤的保护作用。
Objective To investigate the expression of caveolin -1(Cav -1) under different ventilator conditions and to explain clearly the relationship between the expressions of Cav -1 and the activation of p38 MAPK signal in lung tissue in stress injury model .Methods Fifty-six healthy male SD rats (weighting 220-330 g) were randomly assigned into 7 groups according to the tidal volume (VT), respiratory rate (RR) and duration of mechanical ventilation.They were spontaneous breathing control group (group A) which was only done tracheotomy;protective mechanical ventilation group (group B1 and B2) with VT of 6 mL/kg and RR of 60 bpm, and B1 and B2 group ventilation duration was 1 h and 2 h, respectively;Large-tidal volume ventilation group ( group C1, C2, D1, D2, VT 30 mL/kg, RR 40 bpm, ventilation duration 1 h, 2 h), but only rat in group D1 and D2 were intraperitoneally injected with SB203580, a specific inhibitor of p38 MAPK.Hemodynamic parameters and arterial blood gases of all the rats in the 7 groups were measured throughout the study period .After maintaining ventilation for 1 h or 2 h, all rats were sacrificed and specimens of lung tissues and bronchoalveolar lavage fluid (BALF) were harvested. Lung pathological changes were observed by microscopy .The protein levels of Cav -1, p38 MAPK, and AP-1 in lung tissues were assayed with immunohistochemistry staining .The expression levels of Cav-1, MKK3, p38 MAPK mRNA in lung tissue were measured by reverse transcription -polymerase chain reaction (RT-PCR).Lung myeloperoxidase (MPO) activity and wet-dry weight ratio (W/D) were measured.The levels of total protein and interleukin-6 (IL-6) in BALF were measured by enzyme-link immunosorbent assay (ELISA).Results Compared with normal control group A, the expression of p38 MAPK, MKK3, Cav-1 mRNA and Cav -1, p38 MAPK protein was significantly up -regulated; the W/D ratio, MPO, concentration of IL -6 in BALF and total protein increased in group C; however, AP -1 protein was significantly down-regulated.The expression of p38 MAPK, MKK3, Cav-1 mRNA and Cav -1, p38 MAPK protein were significantly higher in group C than those in group of B; the W/D ratio, MPO, concentration of IL-6 in BALF and total protein were increased, but AP-1 protein was significantly lower in group C compared with group B.Compared with group C, expression of p38 MAPK, MKK3 mRNA and p38 MAPK protein was significantly lower in group D while Cav-1 mRNA, Cav-1 and AP-1 protein.W/D ratio, MPO, concentration of IL-6 in BALF and total protein were increased.Conclusion Cav-1 and the activation of p38 MAPK signal in lung tissue participate in the protective effects of the ventilator -induced lung injury.
出处
《中国急救医学》
CAS
CSCD
北大核心
2014年第12期1133-1137,I0012,I0013,共7页
Chinese Journal of Critical Care Medicine
基金
广西壮族自治区自然科学基金