Both membrane stretch and fatty acids directly activate large conductance Ca2+‐activated K+ channels in vascular smooth muscle cells

FEBS Letters

Kirber, Michael T.¹  Clapp, Lucie H.²  Ordway, Richard W.¹  Walsh, John V.¹  Singer, Joshua J.¹ 

[1] Department of Physiology, University of Massachusetts Medical School, Worcester, MA, USA;Department of Pharmacology, United Medical and Dental Schools, St Thomas's Hospital, London, UK

关键词: Ca2+-activated K+ channel;    Stretch-activated channel;    Fatty acid;    Vascular smooth muscle;    Rabbit pulmonary artery;   

DOI  :  10.1016/0014-5793(92)80319-C

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Large conductance Ca²⁺-activated K⁺ channels in rabbit pulmonary artery smooth muscle cells are activated by membrane stretch and by arachidonic acid and other fatty acids. Activation by stretch appears to occur by a direct effect of stretch on the channel itself or a closely associated component. In excised inside-out patches stretch activation was seen under conditions which precluded possible mechanisms involving cytosolic factors, release of Ca²⁺ from intracellular stores, or stretch induced transmembrane flux of Ca²⁺ or other ions potentially capable or activating the channel, Fatty acids also directly activate this channel. Like stretch activation, fatty acid activation occurs in excised inside-out patches in the absence of cytosolic constituents. Moreover, the channel is activated by fatty acids which, unlike arachidonic acid, are not substrates for the cyclo-oxygenase or lypoxygenase pathways, indicating that oxygenated metabolites do not mediate the response. Thus, four distinct types of stimuli (cytosolic Ca²⁺, membrane potential, membrane stretch, and fatty acids) can directly affect the activity of this channel.

【 授权许可】

Unknown