Altered elementary calcium release events and enhanced calcium release by thymol in rat skeletal muscle. 2004

Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
Department of Physiology, Research Center for Molecular Medicine, Medical and Health Science Center, University of Debrecen, Debrecen, Hungary.

The effects of thymol on steps of excitation-contraction coupling were studied on fast-twitch muscles of rodents. Thymol was found to increase the depolarization-induced release of calcium from the sarcoplasmic reticulum, which could not be attributed to a decreased calcium-dependent inactivation of calcium release channels/ryanodine receptors or altered intramembrane charge movement, but rather to a more efficient coupling of depolarization to channel opening. Thymol increased ryanodine binding to heavy sarcoplasmic reticulum vesicles, with a half-activating concentration of 144 micro M and a Hill coefficient of 1.89, and the open probability of the isolated and reconstituted ryanodine receptors, from 0.09 +/- 0.03 to 0.22 +/- 0.04 at 30 micro M. At higher concentrations the drug induced long-lasting open events on a full conducting state. Elementary calcium release events imaged using laser scanning confocal microscopy in the line-scan mode were reduced in size, 0.92 +/- 0.01 vs. 0.70 +/- 0.01, but increased in duration, 56 +/- 1 vs. 79 +/- 1 ms, by 30 micro M thymol, with an increase in the relative proportion of lone embers. Higher concentrations favored long events, resembling embers in control, with duration often exceeding 500 ms. These findings provide direct experimental evidence that the opening of a single release channel will generate an ember, rather than a spark, in mammalian skeletal muscle.

UI MeSH Term Description Entries
D008564 Membrane Potentials The voltage differences across a membrane. For cellular membranes they are computed by subtracting the voltage measured outside the membrane from the voltage measured inside the membrane. They result from differences of inside versus outside concentration of potassium, sodium, chloride, and other ions across cells' or ORGANELLES membranes. For excitable cells, the resting membrane potentials range between -30 and -100 millivolts. Physical, chemical, or electrical stimuli can make a membrane potential more negative (hyperpolarization), or less negative (depolarization). Resting Potentials,Transmembrane Potentials,Delta Psi,Resting Membrane Potential,Transmembrane Electrical Potential Difference,Transmembrane Potential Difference,Difference, Transmembrane Potential,Differences, Transmembrane Potential,Membrane Potential,Membrane Potential, Resting,Membrane Potentials, Resting,Potential Difference, Transmembrane,Potential Differences, Transmembrane,Potential, Membrane,Potential, Resting,Potential, Transmembrane,Potentials, Membrane,Potentials, Resting,Potentials, Transmembrane,Resting Membrane Potentials,Resting Potential,Transmembrane Potential,Transmembrane Potential Differences
D009119 Muscle Contraction A process leading to shortening and/or development of tension in muscle tissue. Muscle contraction occurs by a sliding filament mechanism whereby actin filaments slide inward among the myosin filaments. Inotropism,Muscular Contraction,Contraction, Muscle,Contraction, Muscular,Contractions, Muscle,Contractions, Muscular,Inotropisms,Muscle Contractions,Muscular Contractions
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
D002462 Cell Membrane The lipid- and protein-containing, selectively permeable membrane that surrounds the cytoplasm in prokaryotic and eukaryotic cells. Plasma Membrane,Cytoplasmic Membrane,Cell Membranes,Cytoplasmic Membranes,Membrane, Cell,Membrane, Cytoplasmic,Membrane, Plasma,Membranes, Cell,Membranes, Cytoplasmic,Membranes, Plasma,Plasma Membranes
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
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
D012519 Sarcoplasmic Reticulum A network of tubules and sacs in the cytoplasm of SKELETAL MUSCLE FIBERS that assist with muscle contraction and relaxation by releasing and storing calcium ions. Reticulum, Sarcoplasmic,Reticulums, Sarcoplasmic,Sarcoplasmic Reticulums
D013943 Thymol A phenol obtained from thyme oil or other volatile oils used as a stabilizer in pharmaceutical preparations, and as an antiseptic (antibacterial or antifungal) agent. 2-Isopropyl-5-Methyl-Phenol,2-Isopropyl-5-Methylphenol,Phenol, 5-methyl-2-(1-methylethyl)-,Apiguard,2 Isopropyl 5 Methyl Phenol,2 Isopropyl 5 Methylphenol
D015640 Ion Channel Gating The opening and closing of ion channels due to a stimulus. The stimulus can be a change in membrane potential (voltage-gated), drugs or chemical transmitters (ligand-gated), or a mechanical deformation. Gating is thought to involve conformational changes of the ion channel which alters selective permeability. Gating, Ion Channel,Gatings, Ion Channel,Ion Channel Gatings
D051381 Rats The common name for the genus Rattus. Rattus,Rats, Laboratory,Rats, Norway,Rattus norvegicus,Laboratory Rat,Laboratory Rats,Norway Rat,Norway Rats,Rat,Rat, Laboratory,Rat, Norway,norvegicus, Rattus

Related Publications

Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
September 1995, Science (New York, N.Y.),
Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
January 2008, The Journal of membrane biology,
Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
August 2021, Scientific reports,
Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
January 2006, Journal of muscle research and cell motility,
Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
April 1993, The Journal of physiology,
Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
May 2006, Biophysical journal,
Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
January 2001, American journal of physiology. Cell physiology,
Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
October 2009, Physiological reviews,
Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
September 2002, European biophysics journal : EBJ,
Péter Szentesi, and Henrietta Szappanos, and Csaba Szegedi, and Monika Gönczi, and István Jona, and Julianna Cseri, and László Kovács, and László Csernoch
December 2001, The Journal of physiology,
Copied contents to your clipboard!