REGULATION OF ION CHANNELS IN VASCULAR SMOOTH MUSCLE

血管平滑肌离子通道的调节

• 批准号: 3357833
• 负责人: NICHOLAS SPERELAKIS
• 金额: $ 16.98万
• 依托单位: UNIVERSITY OF CINCINNATI
• 依托单位国家: 美国
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-01 至 1993-06-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/3357833
• 关键词: G protein; angiotensin II; calcium channel; cardiovascular pharmacology; electrophysiology; guinea pigs; hypertension; laboratory rat; neurotransmitters; phosphatidylinositols; phosphorylation; potassium channel; tissue /cell culture; vascular smooth muscle; vasoactive agent; vasomotion

The ion channels in the membrane of vascular smooth muscle cells play an important role in excitation-contraction coupling and in setting vasomotor tone. The activity of these ion channels is controlled by neurotransmitters such as norepinephrine, vasoactive hormones such as angiotensin-II, an clinically useful drugs such as Ca2+ antagonists. The ion channels may be regulated either directly or indirectly by these substances, and the regulatory processes may include the formation or release of intracellular messengers, such as Ca2+, ATP, G-proteins, cyclic AMP, cyclic GMP, inositol phosphates (IP3/IP4), and diacylglycerol. In some disease states, the properties and/or regulation of the ion channels may be altered. Since blood vessels from different regions have different degrees of excitability,k the proportion of various ion channels and/or their regulatory processes may differ also. The objective of this study is to investigate in detail the specific characteristics and regulatory mechanisms for the ion channels, including the various types of Ca2+ and K+ channels, in freshly isolated and cultured vascular smooth muscle cells. Macroscopic and microscopic (single-channel) currents will be recorded using whole-cell voltage clamp and patch-clamp techniques, respectively. The influence of intracellular levels of Ca2+, ATP, and cyclic nucleoties on the activity of Ca2+ and K+ channels will be determined by intracellular perfusion of these substances. A possible role of phosphorylation mediated by various protein kinases (i.e., cyclic nucleotide-dependent, Ca2+/calmodulin-dependent, and Ca2+/phospholipid-dependent) in regulating ion channel activity and cellular excitability will be explored. The mechanism of action of vasoactive substances will be investigated. The possible role of phosphoinositide metabolism (i.e., IP3, IP4, and diacyclglycerol formation) in the electrophysiological actions of agonists such as angiotensin-II will be assessed. The possible gating of ion channels by G-proteins will also be investigated. The results of these studies should provide comprehensive information about how ion channels in vascular smooth muscle function and are regulated and should help to clarify how cellular excitability is altered by important vasoactive substances.

血管平滑肌细胞膜上的离子通道起着 在兴奋-收缩耦合和设置血管舒缩中发挥重要作用 语气。 这些离子通道的活性由以下因素控制 神经递质如去甲肾上腺素、血管活性激素如 血管紧张素-II，一种临床上有用的药物，如Ca2+拮抗剂。 这 离子通道可以直接或间接地受这些调节 物质，监管过程可能包括形成或 释放细胞内信使，如 Ca2+、ATP、G 蛋白、循环 AMP、环 GMP、磷酸肌醇 (IP3/IP4) 和二酰基甘油。 在 某些疾病状态、离子通道的特性和/或调节 可能会被改变。 由于不同部位的血管有不同的 兴奋度，k 各种离子通道的比例和/或 它们的监管流程也可能有所不同。 本研究的目的是 详细调查具体特征和监管 离子通道的机制，包括各种类型的 Ca2+ 和 K+ 通道，在新鲜分离和培养的血管平滑肌细胞中。 将记录宏观和微观（单通道）电流 分别使用全细胞电压钳和膜片钳技术。 细胞内 Ca2+、ATP 和环核水平的影响 Ca2+ 和 K+ 通道的活性由细胞内的 这些物质的灌注。 磷酸化介导的可能作用 通过各种蛋白激酶（即，环核苷酸依赖性， Ca2+/钙调蛋白依赖性和 Ca2+/磷脂依赖性）在调节中的作用 将探讨离子通道活性和细胞兴奋性。 这 将研究血管活性物质的作用机制。 这 磷酸肌醇代谢（即 IP3、IP4 和 二环甘油形成）在激动剂的电生理作用中 将评估血管紧张素-II 等。 离子的可能门控 G 蛋白的通道也将被研究。 这些结果 研究应提供有关离子通道如何参与的全面信息 血管平滑肌功能并受到调节，应该有助于 阐明重要的血管活性物质如何改变细胞兴奋性 物质。