Biomaterial Database

Radiocalcium release by stimulated and potassium-treated sartorius muscles of the frog. 1960

A M SHANES, and C P BIANCHI

Stimulation of frog (Rana pipiens) sartorius muscle accelerates release of Ca(45), but only during the period of stimulation. No appreciable difference is obtained in the calcium released per impulse whether stimulation is at a rate of 20/sec. or 0.5/sec. However, prior stimulation may appreciably increase the loss per impulse. In unfatigued muscles, the minimum amount of calcium liberated during an isotonic twitch is estimated to be about that previously calculated to enter, viz. 0.2 micromicromole/cm(2). The time course of radiocalcium release during potassium depolarization depends on the nature of the contracture. When contracture is isometric, the rate of escape is doubled and declines only slowly; if isotonic, the rate is quadrupled but declines in a few minutes to a level maintained at about double that before potassium. The minimal calcium release during the first 10 minutes of potassium treatment is estimated to be about the same in both cases and about one-half to one-third the uptake. This, and especially the close equality of calcium entry and exit during electrical stimulation, are pointed out as not necessarily inconsistent with a transitory net entry of calcium, comparable to the influx, into restricted regions of the individual fibers.

UI	MeSH Term	Description	Entries
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, 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.
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
D001001	Anura	An order of the class Amphibia, which includes several families of frogs and toads. They are characterized by well developed hind limbs adapted for jumping, fused head and trunk and webbed toes. The term "toad" is ambiguous and is properly applied only to the family Bufonidae.	Bombina,Frogs and Toads,Salientia,Toad, Fire-Bellied,Toads and Frogs,Anuras,Fire-Bellied Toad,Fire-Bellied Toads,Salientias,Toad, Fire Bellied,Toads, Fire-Bellied
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