Putative ryanodine receptors in the sarcolemma of ventricular myocytes
RP Kondo, JN Weiss, JI Goldhaber - Pflügers Archiv, 2000 - Springer
RP Kondo, JN Weiss, JI Goldhaber
Pflügers Archiv, 2000•SpringerThe 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 …
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 …
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.
Springer
