The rate and capacity of calcium uptake by sarcoplasmic reticulum in fast, slow, and cardiac muscle: effects of ryanodine and ruthenium red.
Arch Biochem Biophys
; 265(1): 171-82, 1988 Aug 15.
Article
en En
| MEDLINE
| ID: mdl-2458069
ABSTRACT
The rate and capacity of oxalate-supported calcium uptake was measured in homogenates of rat fast, slow, and cardiac muscle. The contribution of the releasing fraction of the sarcoplasmic reticulum (SR) to the calcium uptake abilities was estimated using ruthenium red or ryanodine to block the release channel. A relatively small fraction (12-20%) of the calcium pumping activity was associated with the release channel in skeletal muscle compared to 50% or more in cardiac muscle. The total capacity of the SR in the muscle types was in the ratio 10.751.5 for cardiac, slow, and fast muscle, respectively, while the rates of uptake were in the ratio 13.814.4. The major difference in the muscle types appears to be the density of pumping activity in the SR rather than the volume of the SR. The difference in the density of pumping activity is due to intrinsic differences in the kinetics of the calcium pump units and in their surface density.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Rutenio
/
Rojo de Rutenio
/
Rianodina
/
Retículo Sarcoplasmático
/
Calcio
/
Alcaloides
/
Músculos
/
Miocardio
Límite:
Animals
Idioma:
En
Revista:
Arch Biochem Biophys
Año:
1988
Tipo del documento:
Article