Biomaterial Database

Termination of Ca2+ release during Ca2+ sparks in rat ventricular myocytes. 1998

V Lukyanenko, and T F Wiesner, and S Gyorke

Department of Physiology, Texas Tech University Health Science Center, Lubbock, TX 79430, USA.

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.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008956	Models, Chemical	Theoretical representations that simulate the behavior or activity of chemical processes or phenomena; includes the use of mathematical equations, computers, and other electronic equipment.	Chemical Models,Chemical Model,Model, Chemical
D002118	Calcium	A basic element found in nearly all tissues. It is a member of the alkaline earth family of metals with the atomic symbol Ca, atomic number 20, and atomic weight 40. Calcium is the most abundant mineral in the body and combines with phosphorus to form calcium phosphate in the bones and teeth. It is essential for the normal functioning of nerves and muscles and plays a role in blood coagulation (as factor IV) and in many enzymatic processes.	Coagulation Factor IV,Factor IV,Blood Coagulation Factor IV,Calcium-40,Calcium 40,Factor IV, Coagulation
D002478	Cells, Cultured	Cells propagated in vitro in special media conducive to their growth. Cultured cells are used to study developmental, morphologic, metabolic, physiologic, and genetic processes, among others.	Cultured Cells,Cell, Cultured,Cultured Cell
D005456	Fluorescent Dyes	Chemicals that emit light after excitation by light. The wave length of the emitted light is usually longer than that of the incident light. Fluorochromes are substances that cause fluorescence in other substances, i.e., dyes used to mark or label other compounds with fluorescent tags.	Flourescent Agent,Fluorescent Dye,Fluorescent Probe,Fluorescent Probes,Fluorochrome,Fluorochromes,Fluorogenic Substrates,Fluorescence Agents,Fluorescent Agents,Fluorogenic Substrate,Agents, Fluorescence,Agents, Fluorescent,Dyes, Fluorescent,Probes, Fluorescent,Substrates, Fluorogenic
D006321	Heart	The hollow, muscular organ that maintains the circulation of the blood.	Hearts
D006352	Heart Ventricles	The lower right and left chambers of the heart. The right ventricle pumps venous BLOOD into the LUNGS and the left ventricle pumps oxygenated blood into the systemic arterial circulation.	Cardiac Ventricle,Cardiac Ventricles,Heart Ventricle,Left Ventricle,Right Ventricle,Left Ventricles,Right Ventricles,Ventricle, Cardiac,Ventricle, Heart,Ventricle, Left,Ventricle, Right,Ventricles, Cardiac,Ventricles, Heart,Ventricles, Left,Ventricles, Right
D000465	Algorithms	A procedure consisting of a sequence of algebraic formulas and/or logical steps to calculate or determine a given task.	Algorithm
D000814	Aniline Compounds	Compounds that include the aminobenzene structure.	Phenylamine,Phenylamines,Anilines,Compounds, Aniline
D000818	Animals	Unicellular or multicellular, heterotrophic organisms, that have sensation and the power of voluntary movement. Under the older five kingdom paradigm, Animalia was one of the kingdoms. Under the modern three domain model, Animalia represents one of the many groups in the domain EUKARYOTA.	Animal,Metazoa,Animalia