Mechanism of the stimulation of Ca2+-dependent ATPase of skeletal muscle sarcoplasmic reticulum by protein kinase

1983 ◽  
Vol 731 (1) ◽  
pp. 79-87 ◽  
Author(s):  
Evangelia G. Kranias ◽  
Frederick J. Samaha ◽  
Arnold Schwartz
Keyword(s):  
Skeletal Muscle ◽  
Protein Kinase ◽  
Sarcoplasmic Reticulum ◽  
Dependent Atpase ◽  
Stimulation Of

scholarly journals Ca-ATPase isozyme expression in sarcoplasmic reticulum is altered by chronic stimulation of skeletal muscle

FEBS Letters ◽  
1990 ◽  
Vol 259 (2) ◽  
pp. 269-272 ◽  
Author(s):  
F.Norman Briggs ◽  
K.Francis Lee ◽  
Joseph J. Feher ◽  
Andrew S. Wechsler ◽  
Kay Ohiendieck ◽  
...  
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Chronic Stimulation ◽  
Stimulation Of

Ca2+ Uptake Coupled to Glycogen Phosphorolysis in the Glycogenolytic-Sarcoplasmic Reticulum Complex from Rat Skeletal Muscle

1996 ◽  
Vol 51 (7-8) ◽  
pp. 591-598 ◽  
Author(s):  
M. Nogues ◽  
A. Cuenda ◽  
F. Henao ◽  
C. Gutiérrez-Merino
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Glycogen Phosphorylase ◽  
Rat Skeletal Muscle ◽  
Subcellular Structure ◽  
Sequential Action ◽  
Physiological Conditions ◽  
Low Concentrations ◽  
Ischemic Muscle ◽  
Stimulation Of

Abstract The glycogenolytic-sarcoplasmic reticulum complex from rat skeletal muscle accumulates Ca2+ upon stimulation of glycogen phosphorolysis in the absence of added ATP. It is shown that an efficient Ca2+ uptake involves the sequential action of glycogen phosphorylase, phosphoglucomutase and hexokinase, which generate low concentrations of ATP (approximately 1 -2 μм) compartmentalized in the immediate vicinity of the sarcoplasmic reticulum Ca2+, Mg2+-ATPase (the Ca2+ pump). The Ca2+ uptake supported by glycogenolysis in this subcellular structure is strongly stimulated by micromolar concentrations of AMP, showing that the glycogen phosphorylase associated with this complex is in the dephosphorylated b form. The results point out that the flux through this compartmentalized metabolic pathway should be enhanced in physiological conditions leading to increased AMP concentrations in the sarcoplasm, such as long-lasting contractions and in ischemic muscle.

Ca(2+)- and pH-dependent halothane stimulation of Ca2+ release in sarcoplasmic reticulum from frog muscle

1996 ◽  
Vol 271 (2) ◽  
pp. C540-C546 ◽  
Author(s):  
M. Beltran ◽  
R. Bull ◽  
P. Donoso ◽  
C. Hidalgo
Keyword(s):  
Skeletal Muscle ◽  
Sarcoplasmic Reticulum ◽  
Calcium Release ◽  
Release Kinetics ◽  
Frog Muscle ◽  
Time Range ◽  
Frog Skeletal Muscle ◽  
Open Probability ◽  
Filtration System ◽  
Stimulation Of

The effect of halothane on calcium release kinetics was studied in triad-enriched sarcoplasmic reticulum vesicles from frog skeletal muscle. Release from vesicles passively equilibrated with 3 mM 45CaCl2 was measured in the millisecond time range by use of a fast-filtration system. Halothane (400 microM) increased release rate constants at pH 7.1 and 7.4 as a function of extravesicular pCa. In contrast, halothane at pH 6.8 produced the same stimulation of release from pCa 7.0 to 3.0; no release took place in these conditions in the absence of halothane. Halothane shifted the calcium activation curve at pH 7.1, but not at pH 7.4, to the left and increased channel open probability at pH 7.1 in the cis pCa range of 7.0 to 5.0. These results indicate that cytosolic pCa and pH modulate the stimulatory effects of halothane on calcium release. Furthermore, halothane stimulated release in frog skeletal muscle at low pH and resting calcium concentration, indicating that in frog muscle halothane can override the closing of the release channels produced by these conditions, as it does in malignant hyperthermia-susceptible porcine muscle.

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