What question did this study set out to answer?

Investigate how ATP regulates the binding and stoichiometric exchange of calcium, magnesium, potassium, and hydrogen ions across isolated skeletal muscle sarcoplasmic reticulum membranes.

May 1, 1967The Journal of General PhysiologyOpen Access

Effects of ATP on the Interaction of Ca++, Mg++, and K+ with Fragmented Sarcoplasmic Reticulum Isolated from Rabbit Skeletal Muscle

View Full Paper

Ask AI

Bookmark

Authors

ACArsélio P. CarvalhoUniversity of Coimbra BLBarbara LeoWestchester Institute for Human Development

Discussion

Member takes

Implication

No immediate clinical implications; hypothesis-generating for ATP-dependent SR cation exchange in skeletal muscle.

Key Points

Investigate how ATP regulates the binding and stoichiometric exchange of calcium, magnesium, potassium, and hydrogen ions across isolated skeletal muscle sarcoplasmic reticulum membranes.
Isolated fragmented sarcoplasmic reticulum from rabbit skeletal muscle to evaluate cation-binding capacity at neutral and acidic pH conditions.
Assayed ion exchange and calcium binding across varying calcium concentrations in the presence and absence of ATP.
Tested the modulatory effects of caffeine (10 mM), procaine (5 mM), acetylcholine, and epinephrine on calcium release and binding.
Isolated sarcoplasmic reticulum exhibited a total cation-binding capacity of ~350 µeq/g of protein at neutral pH, maintaining a constant sum of bound calcium, magnesium, and potassium that confirms stoichiometric exchange.
ATP selectively enhanced calcium uptake, requiring roughly 1,000-fold lower free calcium concentrations to achieve cation exchange compared to ATP-free conditions.
Caffeine (10 mM) provoked the release of a labile calcium fraction without altering membrane-bound calcium, an effect antagonized by 5 mM procaine, while acetylcholine and epinephrine had no effect.

Cite This Study

Carvalho et al. (1967) studied this question.

synapsesocial.com/papers/6a709d33ce524a4339c454fd https://doi.org/10.1085/jgp.50.5.1327

View Full Paper

Ask AI

Bookmark

Effects of ATP on the Interaction of Ca++, Mg++, and K+ with Fragmented Sarcoplasmic Reticulum Isolated from Rabbit Skeletal Muscle

Discussion

Member takes

Implication

Key Points

Cite This Study

Effects of ATP on the Interaction of Ca++, Mg++, and K+ with Fragmented Sarcoplasmic Reticulum Isolated from Rabbit Skeletal Muscle

Discussion

Member takes

Implication

Key Points

Cite This Study

Also Consider

Also Consider