Cardiovascular effects of intermedin1-53 and its mechanism / 中国应用生理学杂志

ABSTRACT

<p><b>AIM</b>The present study was designed to determined the cardiovascular effects of IMD1-53 in rats and its possible mechanism.</p><p><b>METHODS</b>Isolated rat hearts were perfused by Iangendorff mode, and ventricular function was measured after IMD1-53 perfusion. Meanwhere, we investigated the effects of IMDI) on arterial pressure after intravenous administration of IMD. And cAMP content was detected in rat ventricular and aortic tissues.</p><p><b>RESULTS</b>The results showed that perfusion with IMD significantly enhanced cardiac function and resulted in higher LVSP, +dp/dt(max) and -dp/dt(max) 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 perfusion was 131% higher than control. In addition, intravenous administration of IMD induced a potent decrease in arterial pressureand heart rate, and in aortic tissues, IMD incubation resulted in a 236% increase in cAMP content compared with control group.</p><p><b>CONCLUSION</b>The study reveals that IMD can increase cardiac function and decrease arterial pressure in rat and the effects may be related to cAMP pathway.</p>