Biomaterial Database

Potassium contracture in the tonic bundle isolated from the enlarged flexor carpi radialis muscle of the frog. 1981

Y Hayatsu, and I Kosaka, and M Tsutsu-ura, and T Nagai

The flexor carpi radialis muscle (FCRM) of the frog was divided into phasic and tonic bundles, and the properties of the potassium contracture in the tonic bundle were examined. The potassium contracture was tonic and the contracture induced by K higher than 75 mM consisted of the initial phasic component and of the following sustained component. Both components were abolished by the transverse tubule disruption. The curve relating the peak tension to the log[K]o (activation curve) started at about 15 mM K and reached maximum at about 75 mM K. By reducing [Ca]o, the activation curve shifted downward at higher [K]o, being little affected near the mechanical threshold. The time course of inactivation induced by 20 mM K was slow and monophasic, and was markedly accelerated by reducing [Ca]o. The spontaneous relaxation of the contracture induced by high K was little affected by reducing [ca]o.

UI	MeSH Term	Description	Entries
D008297	Male		Males
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
D009129	Muscle Tonus	The state of activity or tension of a muscle beyond that related to its physical properties, that is, its active resistance to stretch. In skeletal muscle, tonus is dependent upon efferent innervation. (Stedman, 25th ed)	Muscle Tension,Muscle Tightness,Muscular Tension,Tension, Muscle,Tension, Muscular,Tightness, Muscle,Tonus, Muscle
D011188	Potassium	An element in the alkali group of metals with an atomic symbol K, atomic number 19, and atomic weight 39.10. It is the chief cation in the intracellular fluid of muscle and other cells. Potassium ion is a strong electrolyte that plays a significant role in the regulation of fluid volume and maintenance of the WATER-ELECTROLYTE BALANCE.
D011898	Ranidae	The family of true frogs of the order Anura. The family occurs worldwide except in Antarctica.	Frogs, True,Rana,Frog, True,True Frog,True Frogs
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
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
D013997	Time Factors	Elements of limited time intervals, contributing to particular results or situations.	Time Series,Factor, Time,Time Factor
D066298	In Vitro Techniques	Methods to study reactions or processes taking place in an artificial environment outside the living organism.	In Vitro Test,In Vitro Testing,In Vitro Tests,In Vitro as Topic,In Vitro,In Vitro Technique,In Vitro Testings,Technique, In Vitro,Techniques, In Vitro,Test, In Vitro,Testing, In Vitro,Testings, In Vitro,Tests, In Vitro,Vitro Testing, In