| Objective:In this study,we established rat model in vivo to observe:1.the influence of calcium sensitizer MCI-154 to the hemodynamic in rats after myocardial stunning;2.the influence of calcium sensitizer MCI-154 to the cardiac function and structure in rats after acute myocardial infarction,and provide information for further clinical practice.Methods:This study included two parts:1.To observe the influence of MCI-154 in rats after myocardial stunning:thirty-six male Wistar rats were divided into four groups randomly:sham operation group(n=6),operation group(n=10),low-dose MCI-154 injection group(lmg/kg)(n=10)and high-dose MCI-154 group(2mg/kg)(n=10).All rats were anesthetized with intraperitoneal injection of 25%urethane (1ml/kg).The latter three groups were occluded anterior descending branch of left coronary artery with a ligation for 15 minutes and then released to reperfusion 120 minutes to be myocardial stunning models.At the same time of the reperfusion,N.S,or MCI-154 were injected via femoral vein respectively.The parameters of hemodynamics were measured before ligation,at the end of 15 minutes ischemia and at the minutes of 10min,30min,60min,90min,120min after reperfusion.2.To observe the influence of MCI-154 in rats after acute myocardial infarction:in accordance with the methods of the rirst part.Acute myocardial infarction was produced by ligation of the anterior descending branch of left coronary artery for 3 hours.After ligation for 5 minutes,N.S.or MCI-154 were injected via femoral vein respectively.The parameters of hemodynamics were measured before ligation and at the end of 3 hours ischemia.Blood sample was taken at the end of 3 hours to detect the activity of creatine kinase in serum.Myocardial tissue was taken for optical microscope examination in some rats.Reasults:1.Compared with sham operation group,the operation group had notable deterioration in LVSP,+dp/dt max,-dp/dt max(p＜0.05)and increasing in LVEDP(p＜0.01)after reperfusion.MCI-154 significantly increased LVSP,+dp/dt max,-dp/dt max(p＜0.05)and decreased LVEDP(p＜0.05)in a dose-dependent manner compared with the operation group.The HR had no significant difference between the four groups. 2.①:Compared with sham operation group,the operation group had notable deterioration in LVSP,+dp/dt max,-dp/dt max(p＜0.05)and increasing in LVEDP(p＜0.05)at the end of ischemia.The low-dose MCI-154 injection group(1mg/kg)had no significant difference in the parameters of hemodynamics compared with the operation group.The high-dose MCI-154 injection group(2mg/kg)significantly increased LVSP,+dp/dt max,-dp/dt max(p＜0.05)and decreased LVEDP(p＜0.05).The HR had no significant difference between the four groups.②:The activity of creatine kinase in serum was higher in operation group and injection groups than in sham operation group(p＜0.01).The low-dose MCI-154 injection group(1mg/kg)had no significant difference in the activity of creatine kinase in serum compared with the operation group. The activity of creatine kinase in serum was lower in the high-dose MCI-154 injection group(2mg/kg) than in operation group(p＜0.05).③The damage of myocardial cell structure was lighter in the high-dose MCI-154 group than that of the operation group.Conclusions:1.Calcium sensitizer MCI-154 can improve cardiac function in rats with myocardial stunning under the circumstances of having no influence of HR.2.Calcium sensitizer MCI-154 can improve cardiac function and lighten structure damage in rats after acute myocardial infarction under the circumstances of having no influence of HR.3.The protective effects of MCI-154 to heart have a dose-dependent manner. |
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