MYOCARDIAL PROTEIN KINASE C & B-ADRENOCEPTORS IN CHF

心肌蛋白激酶C

• 批准号: 3355990
• 负责人: Chang-Seng Liang
• 金额: $ 11.12万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 1988
• 资助国家: 美国
• 起止时间: 1988-04-01 至 1991-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3355990
• 关键词: adenylate cyclase; beta adrenergic receptor; congestive heart failure; disease /disorder model; dogs; fluorescent dye /probe; heart contraction; phosphorylation; protein kinase C; sarcolemma

Protein kinase C, a Ca2+- and phospholipid-dependent protein phosphorylation enzyme present in myocardium, has been shown recently to induce cardiac beta-adrenergic desensitization by phosphorylation of beta-adrenoceptors. To study whether activation of protein kinase C is responsible for cardiac beta-adrenergic desensitization in congestive heart failure, we propose 1) to compare the number and/or activity of cardiac sarcolemmal protein kinase C in heart failure and sham-operated dogs, 2) to characterize the protein kinase C-catalyzed phosphorylation of endogenous substrate proteins in the myocardium of the heart failure and sham-operated dogs, 3) to study the effect of congestive heart failure on protein kinase C-mediated cellular functions in vitro, using isolated myocyte preparations, 4) to determine whether changes in protein kinase C occur only in the pressure-overloaded right ventricle (chamber-specific) or they are also found in the left ventricle and circulating lymphocytes, and 5) to study whether inhibition of protein kinase C in vivo normalizes myocardial beta-receptor density, adenylate cyclase activity and beta-adrenergic responsiveness in heart failure dogs. Congestive right heart failure will be produced by tricuspid avulsion and progressive pulmonary artery constriction in dogs. Hemodynamic measurements will be taken to characterize the degree of heart failure before the animals are sacrificed. Intrinsic contractile function and inotropic responsiveness of the right ventricle to beta-agonists will be studied, using an isolated right ventricular papillary muscle preparation. Samples will be taken from the right and left ventricles for measuring (3H)-phorbol- 12,13-dibutyrate binding, protein kinase C activity, protein kinase C-catalyze phosphorylation of endogenous substrate proteins, beta- receptor density and adenylate cyclase activity. Isolated myocyte preparations will be used to study the effects of protein kinase C as influenced by congestive heart failure on intracellular hydrogen and calcium concentrations, using fluorescent indicators and spectrofluorimetry. The study incorporates physiological, biochemical and cellular measurements in a conscious animal model. This integrative study will not only further our understanding of the fundamental cellular mechanisms responsible for the decreased sensitivity of the heart to sympathetic stimulation in congestive heart failure, but also may provide us a new modality for the treatment of congestive heart failure.

蛋白激酶C，A Ca2+和磷脂依赖性蛋白 已经显示出在心肌中存在的磷酸化酶 最近通过 β-肾上腺素受体的磷酸化。 研究是否激活 蛋白质激酶C的心脏β-肾上腺素能负责 充血性心力衰竭的脱敏，我们建议1） 比较心脏肌膜蛋白的数量和/或活性 激酶C在心力衰竭和假手术的狗中，2） 表征蛋白激酶C催化的磷酸化的磷酸化 心肌心肌内的内源性底物蛋白 失败和假手术狗，3）研究 蛋白激酶C介导的细胞的充血性心力衰竭 在体外功能，使用孤立的肌细胞制剂，4） 确定蛋白激酶C的变化是否仅发生在 右心室压力过多（特定于室）或它们是 也发现在左心室和循环淋巴细胞中，以及 5）研究是否在体内抑制蛋白激酶C 将心肌β受体密度，腺苷酸环化酶归一化 心力衰竭犬的活性和β-肾上腺素能反应。 充血的心力衰竭将由三尖瓣产生 狗的撕裂和进行性肺动脉收缩。 将采取血液动力学测量以表征该度 牺牲动物之前的心力衰竭。 固有的 权利的收缩功能和肌力响应能力 将使用隔离的右侧研究β-激动剂的心室 心室乳头状肌肉制剂。 样品将被取 从左右心室进行测量（3H） - phorbol- 12,13-二丁酸酯结合，蛋白激酶C活性，蛋白激酶 C催化内源性底物蛋白的磷酸化，β- 受体密度和腺苷酸环化酶活性。 孤立的心肌细胞 制剂将用于研究蛋白激酶的作用 C受细胞内充血性心力衰竭的影响 使用荧光指示剂的氢和钙浓度 和频谱荧光法。 该研究结合了生理学 有意识的动物模型中的生化和细胞测量。 这项综合研究不仅会进一步我们对 负责减少的基本细胞机制 心脏对交通充血中的同情刺激的敏感性 心力衰竭，但也可能为我们提供一种新的方式 充血性心力衰竭的治疗。