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Electrophysiological Characterization of a TRPC‐like Current in Cerebral Arterial Smooth Muscle
Author(s) -
Anfinogenova Yana,
Welsh Donald G.
Publication year - 2009
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.23.1_supplement.lb75
Subject(s) - trpc , niflumic acid , amiloride , chemistry , electrophysiology , vascular smooth muscle , dids , transient receptor potential channel , biophysics , patch clamp , myograph , neuroscience , medicine , smooth muscle , endocrinology , biology , biochemistry , receptor , contraction (grammar) , organic chemistry , membrane , sodium
The goal of this investigation was to isolate and characterize a TRPC‐like current in cerebral arterial smooth muscle cells (VSMCs). Briefly, VSMCs were enzymatically isolated from rat cerebral arteries and whole cell currents monitored using patch clamp electrophysiology. Our initial experiments revealed two subpopulations of VSMCs that displayed either an outwardly rectifying or a doubly rectifying current. The reversal potential of both currents shifted with the Na(+) equilibrium potential and were potently blocked by micromolar concentrations of Gd(3+). A pharmacological characterization subsequently revealed that the doubly rectifying TRPC‐like current was insensitive to Cl(‐) channels inhibitors (DIDS and niflumic acid), amiloride and flufemamate. In contrast, tamoxifen elicited a dual effect both attenuating and activating this current at submicromolar and micromolar concentrations, respectively. Similar to findings from cultured smooth muscle cells, hyposmotic challenge and vasoconstrictor agonists (UTP) activated this TRPC‐like non selective cation current. To summarize, this study is the first to characterize the electrical and pharmacological properties of a doubly‐rectifying TRPC‐like cation current in cerebral VSMCs. Ongoing investigations continue to define the molecular composition of this TRPC‐like current along with it's mechanisms of physiological regulation.