PH REGULATION IN VENTRICULAR CELLS

心室细胞的 PH 调节

• 批准号: 3361212
• 负责人: KENNETH W SPITZER
• 金额: $ 8.04万
• 依托单位: UNIVERSITY OF UTAH
• 依托单位国家: 美国
• 财政年份: 1989
• 资助国家: 美国
• 起止时间: 1989-07-01 至 1992-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3361212
• 关键词: acidity /alkalinity; catecholamines; fluorescent dye /probe; guinea pigs; heart contraction; heart disorder; heart ventricle; hormone regulation /control mechanism; insulin; membrane potentials; microelectrodes; sarcolemma; single cell analysis

The electrical and mechanical properties of mammalian ventricular muscle are markedly affected by changes in local pH. This sensitivity may significantly contribute to the myocardial dysfunction accompanying ventricular ischemia. Hence, the cellular systems for controlling the intracellular acid-base status of ventricular muscle are critically important for maintenance of normal heart function. The mechanism of intracellular pH (pH1) regulation and its modulation by membrane potential and hormones is unresolved in mammalian ventricular muscle and is the principal focus of this project. The secondary objective is to quantify the relationship between pH and contraction. To avoid the problems associated with multicellular cardiac preparations, all experiments will be conducted on single ventricular cells. Fluorescent dyes and ion-selective-microelectrodes will be used to measure intracellular activities of H+, Na, Cl, HCO3 and Ca in individual cells. Membrane potential will be controlled using whole-cell patch clap techniques and a recently developed rapid perfusion system will be used to change external solution composition within 7 msec. Cell contraction will be monitored with a newly developed video motion detector. The results are expected to provide new insight into the ionic requirements, hormonal control and"voltage sensitivity of pH, regulatory systems in mammalian ventricular muscle. The results should also yield new information, obtained under physiologically realistic conditions, concerning the pH1- contraction relationship in ventricular muscle.

哺乳动物心室的电学和机械特性 肌肉明显受到局部 pH 值变化的影响。 这 敏感性可能显着有助于心肌 伴随心室缺血的功能障碍。 因此，蜂窝 控制细胞内酸碱状态的系统 心室肌对于维持 心脏功能正常。 细胞内pH（pH1）的机制 膜电位和激素的调节及其调节 在哺乳动物心室肌中尚未解决，并且是主要的 该项目的重点。 第二个目标是量化 pH 值与收缩的关系。 为了避免出现问题 与多细胞心脏制剂相关，所有实验 将在单个心室细胞上进行。 荧光染料 离子选择性微电极将用于测量 个体细胞内 H+、Na、Cl、HCO3 和 Ca 的活性 细胞。 将使用全细胞控制膜电位 膜片拍技术和最近开发的快速灌注 系统将用于改变内部溶液的外部组成 7 毫秒。 细胞收缩将通过新开发的监测 视频运动探测器。 研究结果预计将提供新的 深入了解离子需求、激素控制和“电压” pH 敏感性、哺乳动物心室调节系统 肌肉。 结果还应该产生新的信息，获得 在实际生理条件下，关于 pH1- 心室肌的收缩关系。