Effects Of Shenmai Injection And Its Bioactive C Omponents Following Ischemia/Reperfusion In Cardiomyocytes

AIM:1.To observe whether the myocardial protection, of Shenmai injections during I/R is partially due to its effect in intracellular calcium homeostasis by relieving phospholamban(PLB) inhibition;2. To observe the effects of Ginsenosides following ischemia/reperfusion in cardiomyocytes;3. To observe whether the pharmacodynamic actions of Shenmai injections is superior to that of the ginseng saponins pure compound.METHODS:The cultured neonatal SD rat cardiomyocytes were divided into eight groups: normoxia group (N), normoxia+Total Saponins Of Panax Ginseng group (N+TSPG), normoxia+rgl group (N+Rg1), normoxia+Shenmai injections group (N+SM), ischemia-reperfusion group (I/R), IR+Rg1,I/R+TSPG, I/R+SM. The phospholamban and Sarco-endoplasmic Reticulum Calcium Atpase (SERCA) mRNA and protein expression,[Ca2+]i and apoptosis rate were detected. RESULT:During I/R, p-PLB protein expression and SERCA mRNA and protein expression decreased, while PLB/SERCA ratio increased. It was inhibited by the treatments of Shenmai injections, not by the corresponding concentration of Rgl. SERCA mRNA and protein expression in I/R+TSPG group are significantly higher than those in I/R group, but be lower than I/R+SM group.It has been showed similar results in the apoptosis rate and intracellular calcium, except the failure in inhibiting cardiomyocytes apoptosis by TSPG treatments during I/R. There were no significant differences in p-PLB protein expression and PLB/SERCA ratio between I/R group and I/R+TSPG group. The difference in mRNA and protein expressions of PLB in all groups was not found between groups.Conclusion:1. The myocardial protection of Shenmai injections during I/R is partially due to its effect in intracellular calcium homeostasis by relieving phospholamban inhibition;2. Total Saponins Of Panax Ginseng can increase [Ca2+]i following ischemia/reperfusion in cardiomyocytes, which may contribute to the upregulation of SERCA expression, rather than phospholamban phosphorylation;3.The pharmacodynamic actions of Shenmai injections may be superior to that of the ginseng saponins pure compound.