The Role Of Caveolin-1in Ventilator Induced Lung Injury In Rat

ObjectiveTo explore the role of caveolin-1in ventilator-induced lung injury(VILI)by observing the expression of caveolin-1、p-P38MAPK and IL-8in the lung tissue of the Wistar rats in different time period of high tidal volume ventilation.MethodsTwenty-four health male Wistar rats were randomly divided into control group.high tidal volume half an hour group(group H-VT0.5h),high tidal volume2hour group(group H-VT2h).The pathological changes of the lungs were observed with light microscope. The levels of total protein in bronchoalveolar lavage fluid (BALF) were measured by Bicinchoninic acid method.The wet/dry weight ratio(W/D) of lung tissues were calculated. The expression of caveolin-1、p-P38MAPK and IL-8in lung tissues of rats were detected by immunohistochemistry(SABC),and their relation was analyzed.Results1.The expression of cav-1in lung tissues of rats:H-VT0.5h group(0.142±0.014) and H-VT2h group(0.267±0.017) were respectiveliy higher than control group (0.118±0.010)(all P<0.01);H-VT0.5h group was higher than control group(P<0.01).2.The expression of IL-8in lung tissues of rats:H-VT2h group(0.609±0.095) was respectiveliy higher than H-VT0.5h group(0.190±0.048) and control group (0.145±0.057)(all P<0.01); H-VT0.5h group was no statistical differences existed compared with control group (P>0.05).3.The expression of p-P38MAPK in lung tissues of rats:H-VT2h group(0.514±0.031) was respectiveliy higher than H-VT0.5h group(0.166±0.010) and control group(0.148±0.016)(all P<0.01); H-VT0.5h group was no statistical differences existed compared with control group (P>0.05).4.The relation of cav-1、IL-8and p-P38MAPK:The correlation analysis between cav-1and p-P38MAPK was positively correlated(r=0.787, P<0.01); The correlation analysis between cav-1and IL-8was positively correlated(r=0.737, P<0.01).5.The lung wet/dry weight ratio and the levels of TP in BALF:H-VT2hgroup [(6.460±0.740),(0.620±0.140)]were respectiveliy higher than H-VT0.5h group [(4.440±0.510),(0.300±0.140)]and control group[(4.20±0.320),(0.220±0.063)](all P<0.01); Compared with control group there were no statistical differences existed of the W/D and the contents of TP in the lung tissues of H-VT0.5h group (P>0.05).6.Histopatholosical findings under light microscope demonstrated that diffused alveolar damage induced by mechanical ventilation was worse with time.Conclusions1. In VILI, the expression of cav-1may be induced, and the role of cav-1in VILI may has two sides protection in thirty minutes and damage effect after two hours.2. Cav-1by activating P38MAPK pathway to be increased the expression of IL-8may be one of the important ways of VILI.