%0 Journal Article %1 Ritt_2000_H666 %A Ritter, M. %A Su, Z. %A Spitzer, K. W. %A Ishida, H. %A Barry, W. H. %D 2000 %J Am. J. Physiol. Heart Circ. Physiol. %K 10666100 ATPase, Animal, Animals, Aortic BALB C, Caffeine, Calcium Calcium, Cardiac Cardiomegaly, Cells, Channels, Confocal, Contraction, Cultured, Disease Diseases, Dyes, Dysfunction, Exchanger, Female, Fluorescence, Fluorescent Gov't, Heart Heart, Homeostasis, Humans, Inbred Intracellular L-Type, Left, Low, Male, Membranes, Mice, Microscopy, Models, Muscle Muscles, Myocardial Myocardium, Non-P.H.S., Non-U.S. Output, P.H.S., Research Reticulum, Sarcoplasmic Sodium, Sodium-Calcium Stenosis, Support, U.S. Valve Ventricles, Ventricular {C}a$^{2+}$-Transporting %N 2 %P H666-9 %T Caffeine-induced Ca$^2+$ sparks in mouse ventricular myocytes. %U http://ajpheart.physiology.org/cgi/content/full/278/2/H666 %V 278 %X Ca$^2+$ sparks are spatially localized intracellular Ca$^2+$ release events that were first described in 1993. Sparks have been ascribed to sarcoplasmic reticulum Ca$^2+$ release channel (ryanodine receptor, RyR) opening induced by Ca$^2+$ influx via L-type Ca$^2+$ channels or by spontaneous RyR openings and have been thought to reflect Ca$^2+$ release from a cluster of RyR. Here we describe a pharmacological approach to study sparks by exposing ventricular myocytes to caffeine with a rapid solution-switcher device. Sparks under these conditions have properties similar to naturally occurring sparks in terms of size and intracellular Ca$^2+$ concentration (Ca$^2+$(i)) amplitude. However, after the diffusion of caffeine, sparks first appear close to the cell surface membrane before coalescing to produce a whole cell transient. Our results support the idea that a whole cell Ca$^2+$(i) transient consists of the summation of sparks and that Ca$^2+$ sparks consist of the opening of a cluster of RyR and confirm that characteristics of the cluster rather than the L-type Ca$^2+$ channel-RyR relation determine spark properties.

@article{Ritt_2000_H666, abstract = {{C}a$^{2+}$ sparks are spatially localized intracellular {C}a$^{2+}$ release events that were first described in 1993. Sparks have been ascribed to sarcoplasmic reticulum {C}a$^{2+}$ release channel (ryanodine receptor, RyR) opening induced by {C}a$^{2+}$ influx via L-type {C}a$^{2+}$ channels or by spontaneous RyR openings and have been thought to reflect {C}a$^{2+}$ release from a cluster of RyR. Here we describe a pharmacological approach to study sparks by exposing ventricular myocytes to caffeine with a rapid solution-switcher device. Sparks under these conditions have properties similar to naturally occurring sparks in terms of size and intracellular {C}a$^{2+}$ concentration ([{C}a$^{2+}$](i)) amplitude. However, after the diffusion of caffeine, sparks first appear close to the cell surface membrane before coalescing to produce a whole cell transient. Our results support the idea that a whole cell [{C}a$^{2+}$](i) transient consists of the summation of sparks and that {C}a$^{2+}$ sparks consist of the opening of a cluster of RyR and confirm that characteristics of the cluster rather than the L-type {C}a$^{2+}$ channel-RyR relation determine spark properties.}, added-at = {2009-06-03T11:20:58.000+0200}, author = {Ritter, M. and Su, Z. and Spitzer, K. W. and Ishida, H. and Barry, W. H.}, biburl = {https://www.bibsonomy.org/bibtex/2d803390554f8fd01438fd306ccdd720d/hake}, description = {The whole bibliography file I use.}, file = {Ritt_2000_H666.pdf:Ritt_2000_H666.pdf:PDF}, interhash = {330b22e877ba1eaad9dbc09572e18604}, intrahash = {d803390554f8fd01438fd306ccdd720d}, journal = {Am. J. Physiol. Heart Circ. Physiol.}, keywords = {10666100 ATPase, Animal, Animals, Aortic BALB C, Caffeine, Calcium Calcium, Cardiac Cardiomegaly, Cells, Channels, Confocal, Contraction, Cultured, Disease Diseases, Dyes, Dysfunction, Exchanger, Female, Fluorescence, Fluorescent Gov't, Heart Heart, Homeostasis, Humans, Inbred Intracellular L-Type, Left, Low, Male, Membranes, Mice, Microscopy, Models, Muscle Muscles, Myocardial Myocardium, Non-P.H.S., Non-U.S. Output, P.H.S., Research Reticulum, Sarcoplasmic Sodium, Sodium-Calcium Stenosis, Support, U.S. Valve Ventricles, Ventricular {C}a$^{2+}$-Transporting}, month = Feb, number = 2, pages = {H666-9}, timestamp = {2009-06-03T11:21:27.000+0200}, title = {Caffeine-induced {C}a$^{2+}$ sparks in mouse ventricular myocytes.}, url = {http://ajpheart.physiology.org/cgi/content/full/278/2/H666}, volume = 278, year = 2000 }