Ryanodine sensitive calcium release channel from left ventricle, septum, and atrium of canine heart.
OBJECTIVE
The aim was to consider the possibility that functionally distinct forms of the ryanodine sensitive calcium release channel are expressed in different regions of heart.


METHODS
Membranous fractions enriched in ryanodine binding activity were isolated from canine left ventricular free wall, interventricular septum, and atrium. Ryanodine receptors (RyR) were purified by sucrose density gradient centrifugation, following solubilisation of sarcoplasmic reticular membranes with the detergent Chaps. Single channel currents were measured, upon reconstitution of sarcoplasmic reticular vesicles and the purified RyR into planar lipid bilayers.


RESULTS
Ryanodine sensitive Ca2+ release channels from three different regions of canine heart displayed the same [3H]ryanodine binding and single channel characteristics.


CONCLUSIONS
The left ventricular free wall, septum, and atrium of canine heart may express functionally related, if not identical, ryanodine receptor/Ca2+ release channels.
Xu
L
L
University of North Carolina at Chapel Hill 27599-7260.
Cohn
A H
AH
Meissner
G
G
D000818:Animals; D002110:Caffeine / Q000494:pharmacology; D015220:Calcium Channels / Q000032:analysis* / Q000187:drug effects / Q000378:metabolism; D002462:Cell Membrane / Q000378:metabolism; D004285:Dogs; D006325:Heart Atria; D006346:Heart Septum; D006352:Heart Ventricles; D008051:Lipid Bilayers; D009124:Muscle Proteins / Q000378:metabolism; D012430:Ruthenium Red / Q000494:pharmacology; D012433:Ryanodine / Q000378:metabolism* / Q000494:pharmacology; D019837:Ryanodine Receptor Calcium Release Channel; D012519:Sarcoplasmic Reticulum / Q000378:metabolism*
D015220:Calcium Channels; D008051:Lipid Bilayers; D009124:Muscle Proteins; D019837:Ryanodine Receptor Calcium Release Channel; D012430:Ruthenium Red; D012433:Ryanodine; D002110:Caffeine