CELLULAR ADAPTATIONS OF MYOCARDIUM TO EXERCISE TRAINING

描述(摘自申请者的摘要)：训练诱导的心肌收缩机制的适应所涉及的细胞机制还不是很清楚。该提案中的工作是在单个心肌细胞水平上测试有关收缩适应的假说。从运动训练的大鼠和久坐不动的对照组的心脏中分离的单个心肌细胞的收缩特性将被测量。将确定训练对等长力的钙敏感性和力的动力学性质(力的发展速率和松弛速率)的影响。运动训练对心肌细胞最大缩短速度和力速关系的影响也将被测定。心肌细胞收缩功能的改变将与收缩蛋白的异构体组成及其磷酸化状态相关。

DESCRIPTION (Adapted from the applicant's abstract): The cellular mechanisms that are involved in training-induced adaptations of the contractile machinery of the myocardium are not well understood. Work in this proposal tests hypotheses regarding contractile adaptations at the level of the single cardiac myocyte. The contractile properties of single cardiac myocytes isolated from the hearts of both exercise trained rats and sedentary controls will be measured. The effect of training on the calcium sensitivity of isometric force and kinetic properties of force (rate of force development and rate of relaxation) will be determined. The effect of exercise training on the maximal shortening velocity and the force-velocity relationship of cardiac myocytes will also be determined. Changes in contractile function of the myocytes will be correlated with the isoform composition of contractile proteins and their phosphorylation state.