Termination of Ca2+ release during Ca2+ sparks in rat ventricular myocytes. Export

@article{citeulike:1137772, abstract = {1. Confocal Ca2+ imaging was used to measure spontaneous release events (Ca2+ sparks) in fluo-3-loaded isolated rat ventricular myocytes. 2. The microscopic Ca2+ release flux underlying Ca2+ sparks was derived by adapting the methods used previously to describe macroscopic Ca2+ release from cell-averaged Ca2+ transients. 3. The magnitude of the local release fluxes varied from 2 to 5 microM ms-1, depending on SR Ca2+ loading conditions. Following spontaneous activation, the release flux rapidly decayed (tau = 6-12 ms). The rate of termination of release flux was found to be directly related to the magnitude of the flux (r2 = 0.88). 4. The rate of termination of local release flux was slowed in the presence of FK506, a compound that is known to reduce inactivation of SR Ca2+ channels in vitro. 5. These results suggest that termination of release flux during sparks is not due to a spontaneous stochastic decay process or local depletion of Ca2+ from the SR, but rather involves an active extinguishing mechanism such as Ca2+-dependent inactivation or adaptation.}, address = {Department of Physiology, Texas Tech University Health Science Center, Lubbock, TX 79430, USA.}, author = {Lukyanenko, V. and Wiesner, T. F. and Gyorke, S.}, citeulike-article-id = {1137772}, citeulike-linkout-0 = {http://jp.physoc.org/cgi/content/abstract/507/3/667}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/9508828}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=9508828}, day = {15}, issn = {0022-3751}, journal = {J Physiol}, keywords = {cicr-termination, confocal, fk506, fluo-3, rat, sparks, sr-fluxes, sr-load, sr-release-flux, ventricular-myocytes}, month = {March}, pages = {667--677}, posted-at = {2008-07-31 01:47:38}, priority = {3}, title = {Termination of Ca2+ release during Ca2+ sparks in rat ventricular myocytes.}, url = {http://jp.physoc.org/cgi/content/abstract/507/3/667}, volume = {507 ( Pt 3)}, year = {1998} }

TY - JOUR ID - citeulike:1137772 L3 - citeulike-article-id:1137772 N2 - 1. Confocal Ca2+ imaging was used to measure spontaneous release events (Ca2+ sparks) in fluo-3-loaded isolated rat ventricular myocytes. 2. The microscopic Ca2+ release flux underlying Ca2+ sparks was derived by adapting the methods used previously to describe macroscopic Ca2+ release from cell-averaged Ca2+ transients. 3. The magnitude of the local release fluxes varied from 2 to 5 microM ms-1, depending on SR Ca2+ loading conditions. Following spontaneous activation, the release flux rapidly decayed (tau = 6-12 ms). The rate of termination of release flux was found to be directly related to the magnitude of the flux (r2 = 0.88). 4. The rate of termination of local release flux was slowed in the presence of FK506, a compound that is known to reduce inactivation of SR Ca2+ channels in vitro. 5. These results suggest that termination of release flux during sparks is not due to a spontaneous stochastic decay process or local depletion of Ca2+ from the SR, but rather involves an active extinguishing mechanism such as Ca2+-dependent inactivation or adaptation. JF - J Physiol SN - 0022-3751 AD - Department of Physiology, Texas Tech University Health Science Center, Lubbock, TX 79430, USA. EP - 677 TI - Termination of Ca2+ release during Ca2+ sparks in rat ventricular myocytes. VL - 507 ( Pt 3) SP - 667 KW - cicr-termination KW - confocal KW - fk506 KW - fluo-3 KW - rat KW - sparks KW - sr-fluxes KW - sr-load KW - sr-release-flux KW - ventricular-myocytes AU - Lukyanenko, V AU - Wiesner, TF AU - Gyorke, S PY - 1998/03/15/ UR - http://jp.physoc.org/cgi/content/abstract/507/3/667 ER -