Intermedin1-53对大鼠心血管功能的影响及机制探讨

目的：研究Intermedin1-53（IMD1—53）对大鼠心脏及血管功能的影响及其作用机制。方法：采用Langendorff方法灌流离体心脏,记录IMD1—53灌流下心功能的变化,并以静脉注射给药方法观察IMD1—53对动脉血压的影响,同时检测心脏及血管组织cAMP含量。结果：IMD1—53灌注明显增强心功能,LVSP,＋dp／dtmax和．dp／dtmax较对照组分别增加45％,51％和37％,并增加冠脉流量。IMD1—53增强心功能的作用可被PKA抑制刺H-89阻断。IMD1-53灌流后的心肌组织cAMP含量升高131％。此外,IMD1—53静脉注射可降低大鼠动脉血压和心率,同时经IMD1-53孵育的血管组织cAMP含量升高236％。结论：IMD1—53有明显的增强心功能及降压作用,该作用可能与cAMP途径有关。

Cardiovascular effects of intermedin1-53 and its mechanism

Aim： The present study was designed to determined the cardiovasctdar effects of IMD1-53 in rats and its possible mechanism. Methods： Isolated rat hearts were peffused by Langendorff mode, and ventrieular function was measured after IMD1-53 perfusion. Meanwhere, we investigated the effects of liVID on arterial pressure after intravenous administration of IMD. And cAMP content was detected in rat ventricular and aortic tissues. Results： The results showed that perfusion with IMD significantly enhanced cardiac function and resulted in higher LVSP, ＋ dp/dtmax and -dp/dtmax by 45%, 51% and 37%, respectively, compared with control and increased coronary infusion flow. The effects of IMD1-53 on cardiac function were antagonized by H-89, an inhibitor of PKA. The content of cAMP in the ventricular tissues after IMD peffusion was 131% higher than control. In addition, intravenous administration of IMD induced a potent decrease in arterial pressure and heart rate, and in aortic tissues , IMD incubation restdted in a 236% increase in cAMP content compared with control group. Conclusion： The study reveals that IMD can increase cardiac function and decrease arterial pressure in rat and the effects may be related to cAMP pathway.