%0 Journal Article %1 Soel_2002_2396 %A Soeller, Christian %A Cannell, Mark B %D 2002 %J Biophys. J. %K Acid, Action Adaptation, Algorithms, Analysis, Animals, Antibodies, Array Bilayers, Biological, Biosensing Butyric C57BL, Calcium Calcium, Cardiac, Cardiovascular, Carrier Cell Cells, Channel Channels, Communication, Comparative Computer Computer-Assisted, Conductivity, Confocal, Connexins, Contraction, Crystalline, Crystallins, Culture Cultured, Diagnostic Differentiation, Diffusion, Dyes, Electric Electrochemistry, Electrophysiology, Enhancement, Epithelial Epitopes, Feasibility Feedback, Fluorescein, Fluorescein-5-isothiocyanate, Fluorescence, Fluorescent Gap Gating, Gov't, Heart, Humans, Hybridization, I, Image Imaging, In Inbred Ion Ions, Junctions, Kinetics, L-Type, Lasers, Lens, Lipid Membrane Membrane, Mice, Microscopy, Models, Multiphoto, Multiphoton, Muscle Muscles, Myocardial Myocardium, Myocytes, Non-P.H.S., Non-U.S. Oligonucleotide Oligonucleotides, Oocytes, P.H.S., Photolysis, Photons, Physiological, Potentials, Processing, Propidium, Proteins, Sequence Signaling, Simulation, Situ Studies, Study, Techniques, %N 5 %P 2396-414 %T Estimation of the sarcoplasmic reticulum Ca$^2+$ release flux underlying Ca$^2+$ sparks. %U http://www.biophysj.org/cgi/content/full/82/5/2396 %V 82 %X Using a combination of experimental and numerical approaches, we have tested two different approaches to calculating the sarcoplasmic reticulum (SR) Ca$^2+$ release flux, which gives rise to cardiac muscle Ca$^2+$ sparks. By using two-photon excited spot photolysis of DM-Nitrophen, known Ca$^2+$ release flux time courses were generated to provide the first experimental validation of spark flux reconstruction algorithms. These artificial Ca$^2+$ sparks show that it is possible to calculate the SR Ca$^2+$ release waveform with reasonable accuracy, provided the flux equations reasonably reflect the properties of the experimental system. Within cardiac muscle cells, we show that Ca$^2+$ flux reconstruction is complicated by the substantial dye binding to proteins, a factor that has not been adequately addressed in previous flux reconstruction algorithms. Furthermore, our numerical experiments suggest that the calculated time course of release flux inactivation based on conventional flux reconstruction algorithms is likely to be in error. We therefore developed novel algorithms based on an explicit dye binding scheme. When these algorithm were applied to evoked Ca$^2+$ sparks in rat cardiac ventricular myocytes, the reconstructed Ca$^2+$ release waveform peaked in ~5 ms and decayed with a halftime of approximately 5 ms. The peak flux magnitude was 7-12 pA, suggesting that sparks must arise from clusters of >15 ryanodine receptors.

@article{Soel_2002_2396, abstract = {Using a combination of experimental and numerical approaches, we have tested two different approaches to calculating the sarcoplasmic reticulum (SR) {C}a$^{2+}$ release flux, which gives rise to cardiac muscle {C}a$^{2+}$ sparks. By using two-photon excited spot photolysis of DM-Nitrophen, known {C}a$^{2+}$ release flux time courses were generated to provide the first experimental validation of spark flux reconstruction algorithms. These artificial {C}a$^{2+}$ sparks show that it is possible to calculate the SR {C}a$^{2+}$ release waveform with reasonable accuracy, provided the flux equations reasonably reflect the properties of the experimental system. Within cardiac muscle cells, we show that {C}a$^{2+}$ flux reconstruction is complicated by the substantial dye binding to proteins, a factor that has not been adequately addressed in previous flux reconstruction algorithms. Furthermore, our numerical experiments suggest that the calculated time course of release flux inactivation based on conventional flux reconstruction algorithms is likely to be in error. We therefore developed novel algorithms based on an explicit dye binding scheme. When these algorithm were applied to evoked {C}a$^{2+}$ sparks in rat cardiac ventricular myocytes, the reconstructed {C}a$^{2+}$ release waveform peaked in ~5 ms and decayed with a halftime of approximately 5 ms. The peak flux magnitude was 7-12 pA, suggesting that sparks must arise from clusters of >15 ryanodine receptors.}, added-at = {2009-06-03T11:20:58.000+0200}, author = {Soeller, Christian and Cannell, Mark B}, biburl = {https://www.bibsonomy.org/bibtex/24bf54c0775f08851e1a5a8d22497b674/hake}, description = {The whole bibliography file I use.}, file = {Soel_2002_2396.pdf:Soel_2002_2396.pdf:PDF}, interhash = {bc5b6b1f8abc32589913a0363d0ffe58}, intrahash = {4bf54c0775f08851e1a5a8d22497b674}, journal = {Biophys. J.}, key = 294, keywords = {Acid, Action Adaptation, Algorithms, Analysis, Animals, Antibodies, Array Bilayers, Biological, Biosensing Butyric C57BL, Calcium Calcium, Cardiac, Cardiovascular, Carrier Cell Cells, Channel Channels, Communication, Comparative Computer Computer-Assisted, Conductivity, Confocal, Connexins, Contraction, Crystalline, Crystallins, Culture Cultured, Diagnostic Differentiation, Diffusion, Dyes, Electric Electrochemistry, Electrophysiology, Enhancement, Epithelial Epitopes, Feasibility Feedback, Fluorescein, Fluorescein-5-isothiocyanate, Fluorescence, Fluorescent Gap Gating, Gov't, Heart, Humans, Hybridization, I, Image Imaging, In Inbred Ion Ions, Junctions, Kinetics, L-Type, Lasers, Lens, Lipid Membrane Membrane, Mice, Microscopy, Models, Multiphoto, Multiphoton, Muscle Muscles, Myocardial Myocardium, Myocytes, Non-P.H.S., Non-U.S. Oligonucleotide Oligonucleotides, Oocytes, P.H.S., Photolysis, Photons, Physiological, Potentials, Processing, Propidium, Proteins, Sequence Signaling, Simulation, Situ Studies, Study, Techniques,}, month = May, number = 5, pages = {2396-414}, timestamp = {2009-06-03T11:21:31.000+0200}, title = {Estimation of the sarcoplasmic reticulum {C}a$^{2+}$ release flux underlying {C}a$^{2+}$ sparks.}, url = {http://www.biophysj.org/cgi/content/full/82/5/2396}, volume = 82, year = 2002 }