摘要:
目的 评价利多卡因对大鼠内毒素性肺损伤时Ras同源基因(Rho)/Rho激酶(ROCK)信号通路的影响.方法 SPF级雄性大鼠Wistar大鼠40只,5~8周龄,体重200~250 g.采用随机数字表法分为5组(n=8):对照组(C组)、LPS组和不同剂量利多卡因组(L1-3组).采用腹腔注射LPS 5 mg/kg(0.1 ml)的方法制备内毒素性肺损伤模型,C组腹腔注射等量生理盐水.腹腔注射LPS前1h时,L1.3组分别腹腔注射利多卡因2、4和8 mg/kg.注射LPS或生理盐水后6h时处死大鼠,制备支气管肺泡灌洗液(BALF),采用ELISA法测定IL-1β、IL-6及TNF-α的浓度;取肺组织,行肺损伤评分,计算湿重/干重(W/D)比值,测定髓过氧化物酶(MPO)活性,采用Western blot法测定肺组织Rho、ROCK1、ROCK2、肌球蛋白磷酸酯酶目标亚基1(MYPT1)、磷酸化MYPT1(p-MYPT1)和ZO-1的表达.计算MYPT1磷酸化水平.结果 与C组比较,其余4组肺组织MPO活性、肺损伤评分、W/D比值、BALF IL-1β、IL-6及TNF-α浓度升高,肺组织Rho、ROCK1和ROCK2表达上调,MYPT1磷酸化水平升高,ZO-1表达下调(P<0.05);与LPS组比较,L1-3组肺组织MPO活性、肺损伤评分、W/D比值、BALF IL-1β、IL-6及TNF-α浓度降低,肺组织Rho、ROCK1和ROCK2表达下调,MYPT1磷酸化水平降低,ZO-1表达上调(P<0.05).结论 利多卡因可抑制大鼠内毒素性肺损伤时Rho/ROCK信号通路活性,该作用可能与利多卡因的抗炎机制有关.%Objective To evaluate the effect of lidocaine on Ras homologue (Rho)/Rho kinase (ROCK) signaling pathway during endotoxin-induced lung injury (LI) in rats.Methods Forty SPF male Wistar rats,aged 5-8 weeks,weighing 200-250 g,were divided into 5 groups (n=8 each) using a random number table method:control group (group C),lipopolysaccharide (LPS) group (group LPS)and lidocaine at 3 different doses groups (L1-3 groups).LI was induced by intraperitoneal LPS 5 mg/kg (0.1 ml).The equal volume of normal saline was given intraperitoneally in group C.Lidocaine 2,4 and 8 mg/kg was intraperitoneally injected at 1 h before LPS administration in L1-3 groups,respectively.The animals were sacrificed at 6 h after LPS or normal saline administration.Broncho-alveolar lavage fluid (BALF) was collected for determination of concentrations of interleukin-1 beta (IL-1β),IL-6 and tumor necrosis factor-alpha (TNF-α) (by enzyme-linked immunosorbent assay).The lung tissues were obtained for examination of the pathological changes which were scored and for measurement of the wet/dry weight ratio (W/D ratio) and activities of myeloperoxidase (MPO) and for determination of the expression of Rho,ROCK1,ROCK2,myosin phosphatase target protein 1 (MYPT1),phosphorylated MYPT1 (p-MYPT1)and ZO-1 (by Western blot).The phosphorylation of MYPT1 was calculated.Results Compared with group C,the activity of MPO,lung injury score,W/D ratio and concentrations of IL-1β,IL-6 and TNF-αin BALF were significantly increased,the expression of Rho,ROCK1 and ROCK2 was up-regulated,the phosphorylation of MYPT-1 was increased,and the expression of ZO-1 was down-regulated in the other four groups (P<0.05).Compared with group LPS,the activity of MPO,lung injury score,W/D ratio and concentrations of IL-1β,IL-6 and TNF-α in BALF were significantly decreased,the expression of Rho,ROCK1 and ROCK2 was down-regulated,the phosphorylation of MYPT-1 was decreased,and the expression of ZO-1 was up-regulated in L1-L3 groups (P<0.05).Conclusion Lidocaine can inhibit activation of Rho/ROCK signaling pathway during endotoxin-induced LI in rats,and the effect may be related to the antiinflammatory mechanism of lidocaine.