The Effect Of Swimming Exercises On The Expression Of Cardiovascular ADMmRNA And RAMP2mRNA In Rats

Based on the structural homogeneity and similarity in physiological effect, adrenomedullin(ADM) and calcitonin gene-related peptide (CGRP) are the important members of the CGRP superfamily, both of which can potently dilate vessel, decrease blood pressure and perhaps play a partial role in the strengthened contraction of cardiac muscle. The mechanism by which ADM and CGRP dilate vessel and potentiate contraction of cardiac muscle is that trans-membrane signal transduction is facilitated by receptors distributing in the membrane of vessel smooth muscle and cardiocyte. To our surprise, modified by different transmembrane activity modifying proteins(RAMPs), the same receptor binds different signal molecules of the CGRP superfamily. For example, calcitonin receptor-like receptors(CRLR) can be modified by RAMP2 to became ADM particular receptor. Published research reports on ADM and receptors areconfined in the fields of medicine and biology. Heretofore, little is known about the effect of acute exercise and long-term training on the expression of ADM and receptors. Long-term sports training induces benign cardiovascular adaptation in every structural level. The main purpose of the research is to survey rats cardiovascular expression of ADMmRNA CGRPmRNA RAMP2mRNA after a eight-week swimming training, and then to elucidate elementarily molecular mechanism of exercise-induced adaptation.24 purebred male Sprague-Dawley rats are divided randomly into three groups: Controlled (CR, n=8) , Exhausted (ER, n=8) ,Trained (TR, n=8) . After swimming training left ventricular muscle and main artery arch are extracted, we are inspecting the expression of ADMmRNA CGRPmRNA RAMP2mRNA by RT-PCR. The results are as follows:1. Comparing with the controlled group,once exhausting exercise has no significant effect on cardiovascular expression of ADMmRNA, RAMP2mRNA and CGRPmRNA.2. Comparing with the controlled group,long-term aerobic swimming training upregulates significantly cardiac expression of ADMmRNA,RAMP2mRNA and CGRPmRNA, suggesting that long-term aerobic training induces benign cardiac adaptation in molecular level; nevertheless, long-term aerobic swimming training downregulates significantly vascular expression of ADMmRNA, and has no significant effect on vascular expression of RAMP2mRNA and CGRPmRNA.