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Both membrane stretch and fatty acids directly activate large conductance Ca(2+)-activated K+ channels in vascular smooth muscle cells.
- Source :
-
FEBS letters [FEBS Lett] 1992 Feb 03; Vol. 297 (1-2), pp. 24-8. - Publication Year :
- 1992
-
Abstract
- Large conductance Ca(2+)-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 of 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.
- Subjects :
- Animals
Arachidonic Acid pharmacology
Cations
Cell Membrane drug effects
Cell Membrane physiology
Membrane Potentials drug effects
Muscle, Smooth, Vascular cytology
Muscle, Smooth, Vascular drug effects
Myristic Acid
Myristic Acids pharmacology
Potassium Channels drug effects
Pulmonary Artery cytology
Pulmonary Artery drug effects
Rabbits
Calcium metabolism
Fatty Acids pharmacology
Muscle, Smooth, Vascular metabolism
Potassium Channels metabolism
Pulmonary Artery metabolism
Subjects
Details
- Language :
- English
- ISSN :
- 0014-5793
- Volume :
- 297
- Issue :
- 1-2
- Database :
- MEDLINE
- Journal :
- FEBS letters
- Publication Type :
- Academic Journal
- Accession number :
- 1551431
- Full Text :
- https://doi.org/10.1016/0014-5793(92)80319-c