Effects of alpha-2 adrenoceptor-regulated MAPK pathway on the lung inflammatory response in a rat model of ventilator-induced lung injury

Objective To elucidate the effect of alpha-2 adrenoceptor-regulated inflammatory signal pathway MAPK on the lung inflammatory response in a rat model of ventilator-induced lung injury.Methods Thirty SPF adult male Sprague-Dawley rats were randomly divided into five groups(n=6 per group):standard ventilation group(C),high-tidal volume ventilation group(H),high-tidal volume ventilation plus dexmedetomidine(D), high-tidal volume ventilation plus yohimbine(Y),high-tidal volume ventilation plus dexmedetomidine and yohimbine (D+Y).The pulmonary pathologic changes were observed.The levels of tumor necrosis factorα,interleukin(IL-1β, IL-6 and IL-10) in the BALF were determined by ELISA assay.The expressions of ERK1/2 and p-ERK1/2 were measured by Western blot method.Results Compared with Group C,Group H,D,Y,and D+Y had a significant pulmonary pathologic changes(P0.01).The expression levels of TNF-α,IL-1β,IL-6 and IL-10 in BALF in Group H,D,Y and D+Y were significantly higher than those in Group C.The indices of lung tissue homogenization and BALF in Group D were significantly lower than those in Group H,D,Y,and D+Y.Conclusion Alpha-2 adrenoceptor agonist significantly attenuated the inflammation response of lung underwent injurious ventilation via regulating the MAPK pathway,indicating that alpha-2 adrenoceptor plays an important role in the pulmonary inflammation of VILI.