MYOCARDIAL RESPONSE TO EXERCISE DURING SENESCENCE

衰老期间心肌对运动的反应

• 批准号: 3117142
• 负责人: CHARLOTTE A TATE
• 金额: $ 15.53万
• 依托单位: UNIVERSITY OF HOUSTON
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-06 至 1995-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3117142
• 关键词: actins; adenosinetriphosphatase; aging; calcium flux; calcium transporting ATPase; cell biology; cytochrome c; exercise; heart circulation; heart contraction; laboratory rat; membrane proteins; messenger RNA; oxygen consumption; protein biosynthesis; recombinant DNA; ribosomal proteins; sarcoplasmic reticulum

The overall aim of the proposed work is to delineate the mechanisms by which exercise training alters the function of the heart in senescent rats. In the senescent rat there is an impaired relaxation of the isolated heart which is associated with a diminished rate of calcium transport by the calcium pump (CaATPase) of the sarcoplasmic reticulum (SR). Endurance exercise training of old rats improves the rate of calcium transport by cardiac SR which is accompanied by a faster relaxation of the isolated heart muscle. Our specific objective is to determine the mechanisms underlying the diminished calcium transport of cardiac SR from old rats and to evaluate the impact exercise training has on those mechanisms. The isometric contractile properties of the isolated papillary muscle and maximal oxygen consumption (maximal capacity) of the rats will be assessed in conjunction with these studies. This objective will be approached by determining the content of the mRNA specific for the CaATPase, total content of the CaATPase protein, and the synthesis rate of the CaATPase protein in the heart through recombinant DNA, immunoprecipitation, and labelling techniques, respectively. Factors at the level of the membrane important to the calcium transport process will be determined in the isolated cardiac SR using a variety of biochemical and antibody techniques. After the cessation of training, the regression of the exercise-induced improvement of the intrinsic contractile properties and calcium transport in the heart will be determined. The impact that exercise has on the aging-related rate of decline in intrinsic contractile performance and calcium transport by cardiac SR will be addressed. The effect of agents and conditions known to modulate calcium movements in the heart will be monitored in isolated cardiac muscle. Finally, the role that phospholamban in cardiac SR has on calcium transport and muscle mechanics will be determined. These studies will give insight into the cellular mechanisms underlying the diminished cardiac function during senescence and the improvement by exercise training which leads to an enhanced quality of life.

拟议工作的总体目标是通过以下方式描述机制： 运动训练会改变衰老大鼠的心脏功能。 衰老大鼠的离体心脏舒张功能受损 这与钙转运速率降低有关 肌浆网 (SR) 的钙泵 (CaATPase)。 耐力 老年大鼠的运动训练通过以下方式提高钙转运速率 心脏 SR 伴随着孤立的更快的松弛 心肌。 我们的具体目标是确定机制 老年大鼠心脏 SR 钙转运减少的潜在原因 评估运动训练对这些机制的影响。 这 离体乳头肌的等长收缩特性和 将评估大鼠的最大耗氧量（最大容量） 结合这些研究。 这一目标将通过 确定 CaATPase 特异性 mRNA 的含量，总含量 CaATPase蛋白含量及CaATPase合成率 通过重组 DNA、免疫沉淀和 分别是标记技术。 膜层面的因素 对于钙转运过程的重要性将在 使用各种生化和抗体技术分离心脏 SR。 停止训练后，运动诱发的回归 改善内在收缩特性和钙转运 心中就会下定决心。 运动对身体的影响 与衰老相关的内在收缩性能下降率和 将讨论心脏 SR 的钙转运问题。 药剂的效果 已知调节心脏钙运动的条件将是 在离体心肌中进行监测。 最后，受磷蛋白的作用 在心脏中 SR 对钙转运和肌肉力学的影响 决定。 这些研究将深入了解细胞机制 衰老过程中心脏功能下降的潜在原因 通过运动训练改善，从而提高质量 生活。