ISSN:
1432-2013
Keywords:
Caffeine Calcium Ryanodine receptor Ion channel Cardiac Ventricular myocyte
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract. The activity of caffeine-activated large conductance channels was recorded in whole-cell, patch-clamped, isolated ventricular myocytes from rabbit heart. The channels were permeable to monovalent and divalent cations and had a unitary monovalent cation conductance of 300–400 pS. Extracellular ruthenium red reduced the unitary conductance of the caffeine-activated channel in a concentration- and voltage-dependent manner. Ryanodine locked the caffeine-activated channels into a subconductance state. Elevating intracellular Ca2+ by photolysis of "caged calcium" increased the number of channel openings. The properties of this caffeine-activated channel were remarkably similar to those of cardiac ryanodine receptors (RyR) and support the novel finding that these channels may also be found on the sarcolemmal membrane.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004240000259
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