Quayle J M, Nelson M T, Standen N B
Department of Cell Physiology and Pharmacology, University of Leicester, United Kingdom.
Physiol Rev. 1997 Oct;77(4):1165-232. doi: 10.1152/physrev.1997.77.4.1165.
The properties and roles of ATP-sensitive (KATP) and inwardly rectifying (KIR) potassium channels are reviewed. Potassium channels regulate the membrane potential of smooth muscle, which controls calcium entry through voltage-dependent calcium channels, and thereby contractility through changes in intracellular calcium. The KATP channel is likely to be composed of members of the inward rectifier channel gene family (Kir6) and sulfonylurea receptor proteins. The KIR channels do not appear to be as widely distributed as KATP channels in smooth muscle and may provide a mechanism by which changes in extracellular K+ can alter smooth muscle membrane potential, and thereby arterial diameter. The KATP channels contribute to the resting membrane conductance of some types of smooth muscle and can open under situations of metabolic compromise. The KATP channels are targets of a wide variety of vasodilators and constrictors, which act, respectively, through adenosine 3',5'-cyclic monophosphate/protein kinase A and protein kinase C. The KATP channels are also activated by a number of synthetic vasodilators (e.g., diazoxide and pinacidil) and are inhibited by the oral hypoglycemic sulfonylurea drugs (e.g., glibenclamide). Together, KATP and KIR channels are important regulators of smooth muscle function and represent important therapeutic targets.
本文综述了ATP敏感性（KATP）钾通道和内向整流（KIR）钾通道的特性与作用。钾通道调节平滑肌的膜电位，而膜电位控制着通过电压依赖性钙通道的钙内流，进而通过细胞内钙的变化来调控收缩性。KATP通道可能由内向整流通道基因家族（Kir6）的成员和磺脲类受体蛋白组成。KIR通道在平滑肌中的分布似乎不如KATP通道广泛，它可能提供了一种机制，使细胞外K+的变化能够改变平滑肌膜电位，从而改变动脉直径。KATP通道对某些类型平滑肌的静息膜电导有贡献，并且在代谢受损的情况下能够开放。KATP通道是多种血管舒张剂和血管收缩剂的作用靶点，它们分别通过3',5'-环磷酸腺苷/蛋白激酶A和蛋白激酶C发挥作用。KATP通道还可被多种合成血管舒张剂（如二氮嗪和平卡地尔）激活，并被口服降糖磺脲类药物（如格列本脲）抑制。总之，KATP和KIR通道是平滑肌功能的重要调节因子，也是重要的治疗靶点。
