Effect of lidocaine on Rho/ROCK signaling pathway during endotoxin-induced acute lung injury in rats / 中华麻醉学杂志

ABSTRACT

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.