Abstract:Abstract: Objective Using the H/R model at cell leve, to observe protective effect and possible mechanism of penehyclidine Hydrochloride on myocardial I/R injur of microvascular endothelial cells.Methods In this experiment carry out cardiac vascular endothelial cells for primary culture were obtained by enzyme digestion1:2 passage.Fluorescent labeling acetylate Dil-Ac-LDL method was used to identification. Cutured cells were randomly divided into 4 groups, ① the normal control group, cultured under normoxic environment and did not give any treatment; ② H/R group,exchanged the culture medium into D-Hank,s liquid,putted it into 37℃、5%CO2、95%N2 a close tightly jar which was hypoxia for 2h,and then retrieved the total culture medium ,putted it into a normoxic environment to continue to culture for 4h; ③ PHC preconditon group,gived PHC(final concentration is 0.1μmol/L) hypoxia before; ④ H/R+ PHC group,after the cells H/R,gived PHC(final concentration is 0.1μmol/L),and continued to culture 2h.Results .The cardiac microvascular endothelial cells of adult rat were cultured successfully. Use fluorescent labeling acetylate Dil-Ac-LDL method to identify the cells. The H/R model of cardiac microvascular endothelial cells was established successfully. Exchange total culture medium into D-Hank,s liquid,put it into a close tightly jar which is on the condition of37℃、5%CO2、95%N2 hypoxia for 2h,and then retrieve the total culture medium ,put it into a normoxic environment to continue to culture for 4h. H/R group, the rate of cell death and apoptosis compared with the control group significantly increased, the difference was statistically significant(P<0.01); PHC+ H/R group,the cells death and apoptosis rate were declined than the H/R group, the differences were significance (P <0.05); H/R + PHC group compared with the control group, although the cells and the apoptosis rate of were decline, but the difference was not statistically significant(P>0.05).Conclusion PHC precondition has protective effects on cardiac microvascular endothelial cells after H/R injury in rats.