Biomaterial Database

Osmotic changes of sarcoplasmic reticulum vesicles during Ca2+ uptake. 1983

T Beeler

The ATP-dependent accumulation of Ca2+ by sarcoplasmic reticulum vesicles at 37 degrees reaches a peak after approximately 100 sec. The Ca2+-loading level then declines until a steady-state level is reached which is 20% less than the peak value. This spontaneous release of Ca2+ is enhanced by inclusion of maleate in the Ca2+ uptake medium. Increasing the extravesicular osmolarity by the addition of sucrose to the Ca2+ uptake medium prevents spontaneous Ca2+ release and increases the steady-state Ca2+-loading capacity of sarcoplasmic reticulum vesicles. Swelling of sarcoplasmic reticulum vesicles during Ca2+ uptake in medium containing sucrose is indicated by changes in the light-scattering intensity. These experiments indicate that the capacity of sarcoplasmic reticulum vesicles to accumulate Ca2+ is limited by the osmotic gradient generated by the increase in intravesicular Ca2+. Swelling of sarcoplasmic reticulum vesicles during Ca2+ uptake causes spontaneous Ca2+ release.

UI	MeSH Term	Description	Entries
D008298	Maleates	Derivatives of maleic acid (the structural formula (COO-)-C
D009132	Muscles	Contractile tissue that produces movement in animals.	Muscle Tissue,Muscle,Muscle Tissues,Tissue, Muscle,Tissues, Muscle
D009995	Osmosis	Tendency of fluids (e.g., water) to move from the less concentrated to the more concentrated side of a semipermeable membrane.	Osmoses
D011817	Rabbits	A burrowing plant-eating mammal with hind limbs that are longer than its fore limbs. It belongs to the family Leporidae of the order Lagomorpha, and in contrast to hares, possesses 22 instead of 24 pairs of chromosomes.	Belgian Hare,New Zealand Rabbit,New Zealand Rabbits,New Zealand White Rabbit,Rabbit,Rabbit, Domestic,Chinchilla Rabbits,NZW Rabbits,New Zealand White Rabbits,Oryctolagus cuniculus,Chinchilla Rabbit,Domestic Rabbit,Domestic Rabbits,Hare, Belgian,NZW Rabbit,Rabbit, Chinchilla,Rabbit, NZW,Rabbit, New Zealand,Rabbits, Chinchilla,Rabbits, Domestic,Rabbits, NZW,Rabbits, New Zealand,Zealand Rabbit, New,Zealand Rabbits, New,cuniculus, Oryctolagus
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
D000252	Calcium-Transporting ATPases	Cation-transporting proteins that utilize the energy of ATP hydrolysis for the transport of CALCIUM. They differ from CALCIUM CHANNELS which allow calcium to pass through a membrane without the use of energy.	ATPase, Calcium,Adenosinetriphosphatase, Calcium,Ca(2+)-Transporting ATPase,Calcium ATPase,Calcium Adenosinetriphosphatase,Adenosine Triphosphatase, Calcium,Ca2+ ATPase,Calcium-ATPase,ATPase, Ca2+,ATPases, Calcium-Transporting,Calcium Adenosine Triphosphatase,Calcium Transporting ATPases,Triphosphatase, Calcium 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
D001693	Biological Transport, Active	The movement of materials across cell membranes and epithelial layers against an electrochemical gradient, requiring the expenditure of metabolic energy.	Active Transport,Uphill Transport,Active Biological Transport,Biologic Transport, Active,Transport, Active Biological,Active Biologic Transport,Transport, Active,Transport, Active Biologic,Transport, Uphill
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
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