Biomaterial Database

Voltage-dependent calcium release in human malignant hyperthermia muscle fibers. 1998

A Struk, and F Lehmann-Horn, and W Melzer

Abteilung für Angewandte Physiologie, Universität Ulm, D-89069 Ulm, Germany.

Malignant hyperthermia (MH) results from a defect of calcium release control in skeletal muscle that is often caused by point mutations in the ryanodine receptor gene (RYR1). In malignant hyperthermia-susceptible (MHS) muscle, calcium release responds more sensitively to drugs such as halothane and caffeine. In addition, experiments on the porcine homolog of malignant hyperthermia (mutation Arg615Cys in RYR1) indicated a higher sensitivity to membrane depolarization. Here, we investigated depolarization-dependent calcium release under voltage clamp conditions in human MHS muscle. Segments of muscle fibers dissected from biopsies of the vastus lateralis muscle of MHN (malignant hyperthermia negative) and MHS subjects were voltage-clamped in a double vaseline gap system. Free calcium was determined with the fluorescent indicator fura-2 and converted to an estimate of the rate of SR calcium release. Both MHN and MHS fibers showed an initial peak of the release rate, a subsequent decline, and rapid turn-off after repolarization. Neither the kinetics nor the voltage dependence of calcium release showed significant deviations from controls, but the average maximal peak rate of release was about threefold larger in MHS fibers.

UI	MeSH Term	Description	Entries
D007700	Kinetics	The rate dynamics in chemical or physical systems.
D008305	Malignant Hyperthermia	Rapid and excessive rise of temperature accompanied by muscular rigidity following general anesthesia.	Hyperpyrexia, Malignant,Hyperthermia, Malignant,Malignant Hyperpyrexia,Anesthesia Related Hyperthermia,Hyperthermia of Anesthesia,Anesthesia Hyperthermia,Hyperthermia, Anesthesia Related,Malignant Hyperpyrexias
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
D004594	Electrophysiology	The study of the generation and behavior of electrical charges in living organisms particularly the nervous system and the effects of electricity on living organisms.
D005453	Fluorescence	The property of emitting radiation while being irradiated. The radiation emitted is usually of longer wavelength than that incident or absorbed, e.g., a substance can be irradiated with invisible radiation and emit visible light. X-ray fluorescence is used in diagnosis.
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000367	Age Factors	Age as a constituent element or influence contributing to the production of a result. It may be applicable to the cause or the effect of a circumstance. It is used with human or animal concepts but should be differentiated from AGING, a physiological process, and TIME FACTORS which refers only to the passage of time.	Age Reporting,Age Factor,Factor, Age,Factors, Age
D018408	Patch-Clamp Techniques	An electrophysiologic technique for studying cells, cell membranes, and occasionally isolated organelles. All patch-clamp methods rely on a very high-resistance seal between a micropipette and a membrane; the seal is usually attained by gentle suction. The four most common variants include on-cell patch, inside-out patch, outside-out patch, and whole-cell clamp. Patch-clamp methods are commonly used to voltage clamp, that is control the voltage across the membrane and measure current flow, but current-clamp methods, in which the current is controlled and the voltage is measured, are also used.	Patch Clamp Technique,Patch-Clamp Technic,Patch-Clamp Technique,Voltage-Clamp Technic,Voltage-Clamp Technique,Voltage-Clamp Techniques,Whole-Cell Recording,Patch-Clamp Technics,Voltage-Clamp Technics,Clamp Technique, Patch,Clamp Techniques, Patch,Patch Clamp Technic,Patch Clamp Technics,Patch Clamp Techniques,Recording, Whole-Cell,Recordings, Whole-Cell,Technic, Patch-Clamp,Technic, Voltage-Clamp,Technics, Patch-Clamp,Technics, Voltage-Clamp,Technique, Patch Clamp,Technique, Patch-Clamp,Technique, Voltage-Clamp,Techniques, Patch Clamp,Techniques, Patch-Clamp,Techniques, Voltage-Clamp,Voltage Clamp Technic,Voltage Clamp Technics,Voltage Clamp Technique,Voltage Clamp Techniques,Whole Cell Recording,Whole-Cell Recordings
D018482	Muscle, Skeletal	A subtype of striated muscle, attached by TENDONS to the SKELETON. Skeletal muscles are innervated and their movement can be consciously controlled. They are also called voluntary muscles.	Anterior Tibial Muscle,Gastrocnemius Muscle,Muscle, Voluntary,Plantaris Muscle,Skeletal Muscle,Soleus Muscle,Muscle, Anterior Tibial,Muscle, Gastrocnemius,Muscle, Plantaris,Muscle, Soleus,Muscles, Skeletal,Muscles, Voluntary,Skeletal Muscles,Tibial Muscle, Anterior,Voluntary Muscle,Voluntary Muscles