Biomaterial Database

Ca2+ capacity and uptake rate in skinned fibers of myodystrophic muscle. 1985

B A Mobley

Parameters related to the capacity and the rate of uptake of calcium ions by the sarcoplasmic reticulum were measured in skinned extensor digitorum longus fibers of control and myodystrophic mice. Single fibers were isolated and skinned in a relaxing solution and mounted on a force transducer and apparatus for changing the bathing solution (T = 25 degrees C). To test the capacity of the sarcoplasmic reticulum, fibers were placed in a solution for maximal loading and then moved to a test solution in which the major anion in the relaxing solution, gluconate, was replaced by chloride. In the resulting contractures, the means of the forces produced by 10 control and myodystrophic fibers were not significantly different. The conclusion is that the capacities of sarcoplasmic reticulum for calcium in control and myodystrophic fibers are equivalent. To test the rate of loading of sarcoplasmic reticulum, 11 control and myodystrophic fibers were depleted of calcium with caffeine and EGTA. Then they were placed in a solution with pCa = 5.5, and the delay before a contracture began was recorded. The delay was the time required for the sarcoplasmic reticulum to load calcium and attain a threshold for calcium-induced calcium release. The mean delay for the control fibers was significantly less than the mean delay in myodystrophic for the control fibers was significantly less than the mean delay in myodystrophic fibers. The disparity of loading times probably reflected a difference in the activities of the calcium pumps or a difference in the number of pump sites; 5 microM valinomycin did not significantly alter the loading times of either type or fiber.

UI	MeSH Term	Description	Entries
D008815	Mice, Inbred Strains	Genetically identical individuals developed from brother and sister matings which have been carried out for twenty or more generations, or by parent x offspring matings carried out with certain restrictions. All animals within an inbred strain trace back to a common ancestor in the twentieth generation.	Inbred Mouse Strains,Inbred Strain of Mice,Inbred Strain of Mouse,Inbred Strains of Mice,Mouse, Inbred Strain,Inbred Mouse Strain,Mouse Inbred Strain,Mouse Inbred Strains,Mouse Strain, Inbred,Mouse Strains, Inbred,Strain, Inbred Mouse,Strains, Inbred Mouse
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
D009137	Muscular Dystrophy, Animal	MUSCULAR DYSTROPHY that occurs in VERTEBRATE animals.	Animal Muscular Dystrophies,Animal Muscular Dystrophy,Dystrophies, Animal Muscular,Dystrophy, Animal Muscular,Muscular Dystrophies, Animal
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
D000251	Adenosine Triphosphatases	A group of enzymes which catalyze the hydrolysis of ATP. The hydrolysis reaction is usually coupled with another function such as transporting Ca(2+) across a membrane. These enzymes may be dependent on Ca(2+), Mg(2+), anions, H+, or DNA.	ATPases,Adenosinetriphosphatase,ATPase,ATPase, DNA-Dependent,Adenosine Triphosphatase,DNA-Dependent ATPase,DNA-Dependent Adenosinetriphosphatases,ATPase, DNA Dependent,Adenosinetriphosphatases, DNA-Dependent,DNA Dependent ATPase,DNA Dependent Adenosinetriphosphatases,Triphosphatase, Adenosine
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
D051379	Mice	The common name for the genus Mus.	Mice, House,Mus,Mus musculus,Mice, Laboratory,Mouse,Mouse, House,Mouse, Laboratory,Mouse, Swiss,Mus domesticus,Mus musculus domesticus,Swiss Mice,House Mice,House Mouse,Laboratory Mice,Laboratory Mouse,Mice, Swiss,Swiss Mouse,domesticus, Mus musculus