Dexmedetomidine alleviates lung tissue injury of rat models with ventilator-associated lung injury / 基础医学与临床

ABSTRACT

Objective To investigate the effect of dexmedetom idine(DEX)on lung tissue and Ras homolog gene family member A(RhoA)/Rho kinase 1(ROCK1)signaling pathway in lung tissue of rats with ventilator-induced lung injury(VILI).Methods A VILI rat model was established and separated into control group,model group(VILI group),dexmedetomidine low and high dose groups(DEX-L,DEX-H group),and high dose dexmedetomi-dine+lysophosphatidic acid(LPA)group(DEX-H+LPA group).Determination of wet/dry mass ratio of rat lung tissue(W/D);HE staining microscopy was applied to observe morphology of lung tissue;ELISA kit was applied to detect the level of tumor necrosis factor-α(TNF-α),interleukin-1β(IL-1β)and interleukin-6(IL-6)in bronchoalveolar lavage fluid(BALF);TUNEL staining method was applied to detect lung epithelial cell death;Immunoblotting was applied to detect the expression levels of apoptosis-related proteins,and RhoA,ROCK1 pro-teins.Results DEX could reduce lung injury,lung injury score,W/D,apoptosis rate,levels of TNF-α,IL-1β,IL-6,and expression of Bax,cleaved caspase-3,RhoA,ROCK,α-SMA in VILI rats(P＜0.05),while increased the expression of Bcl-2(P＜0.05);LPA could aggravate lung injury and increase lung injury score,W/D,apopto-sis rate,level of TNF-α,IL-1β,IL-6 and expressions of Bax,cleaved caspase-3,RhoA,ROCK and α-SMA(P＜0.05);Bcl-2 expression level was decreased(P＜0.05).Conclusions Dexmedetomidine may protect rats with ventilator-induced lung injury by the inhibition of RhoA/ROCK1 signaling pathway.