RESUMO
Objective To investigate the possible mechanism of Xuebijing injection in regulating abnormal degradation of pulmonary vascular endothelial calyx to improve acute lung injury induced by severe heatstroke.Methods Forty-eight Wistar rats were randomly divided into control group,heatstroke group and Xuebijing group.Before heatstroke induction,rats in Xuebijing group were administrated with Xuebijing injection(2 ml/kg,2 times/d)for 3 days.All rats were exposed to an environment with temperature of(40±2)℃and humidity of 65%±5%for 60 minutes to induce heatstroke.Two hours later,the lung wet/dry weight ratio was recorded;the concentration of proteins in BALF was measured;the pulmonary vascular permeability was measured by Evans blue(EB);HE staining was used to observe the pathological changes of lung tissue;the changes of hyaluronic acid(HA)on the surface of pulmonary vessels were observed by immunofluorescence;Western blotting was used to detect the expression of Syndecan-1,Glypican-1,VE-Cadherin,Occludin,VCAM-1 and E-selectin in lung tissues;Enzyme-linked immunosorbent assay(ELISA)was utilized to quantify the concentration of tumor necrosis factor-α(TNF-α),interleukin-6(IL-6)in serum and heparanase(HPA)in lung tissue.Results Xuebijing could decrease the lung wet/dry weight ratio,reduce protein exudation and improve pulmonary vascular permeability(P<0.01);reduce the histological injury(P<0.01);reduce the degradation of HA,Syndecan-1 and Glypican-1 on the surface of pulmonary vessels(P<0.01);increase the expression of VE-Cadherin and Occludin(P<0.01);regulate the overexpression of VCAM-1 and E-selectin(P<0.01);down-regulate the expression of TNF-α,IL-6 and HPA(P<0.01).Conclusion Xuebijing injection decrease the expression of HPA,improve the disintegration of pulmonary vascular endothelial calyx,repair the integrity of pulmonary vessels,reduce the damage of cell connections,down-regulate the expression of adhesion molecules,inhibit the inflammatory reaction,relieving acute lung injury caused by severe heat stroke.