The Influence of Hydrogen Ion Concentration on Calcium Binding and Release by Skeletal Muscle Sarcoplasmic Reticulum (original) (raw)

Abstract

Calcium release and binding produced by alterations in pH were investigated in isolated sarcoplasmic reticulum (SR) from skeletal muscle. When the pH was abruptly increased from 6.46 to 7.82, after calcium loading for 30 sec, 80–90 nanomoles (nmole) of calcium/mg protein were released. When the pH was abruptly decreased from 7.56 to 6.46, after calcium loading for 30 sec, 25–30 nmole of calcium/mg protein were rebound. The calcium release process was shown to be a function of pH change: 57 nmole of calcium were released per 1 pH unit change per mg protein. The amount of adenosine triphosphate (ATP) bound to the SR was not altered by the pH changes. The release phenomenon was not due to alteration of ATP concentration by the increased pH. Native actomyosin was combined with SR in order to study the effectiveness of calcium release from the SR by pH change in inducing super-precipitation of actomyosin. It was found that SR, in an amount high enough to inhibit superprecipitation at pH 6.5, did not prevent the process when the pH was suddenly increased to 7.3, indicating that the affinity of SR for calcium depends specifically on pH. These data suggest the possible participation of hydrogen ion concentration in excitation-contraction coupling.

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Selected References

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  1. Alonso G., Walser M. ATP splitting and calcium binding by brain microsomes measured with a rapid perfusion method. J Gen Physiol. 1968 Jul;52(1):111–135. doi: 10.1085/jgp.52.1.111. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. CONWAY E. J. Nature and significance of concentration relations of potassium and sodium ions in skeletal muscle. Physiol Rev. 1957 Jan;37(1):84–132. doi: 10.1152/physrev.1957.37.1.84. [DOI] [PubMed] [Google Scholar]
  3. Carter N. W., Rector F. C., Jr, Campion D. S., Seldin D. W. Measurement of intracellular pH of skeletal muscle with pH-sensitive glass microelectrodes. J Clin Invest. 1967 Jun;46(6):920–933. doi: 10.1172/JCI105598. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Carvalho A. P., Leo B. Effects of ATP on the interaction of Ca++, Mg++, and K+ with fragmented sarcoplasmic reticulum isolated from rabbit skeletal muscle. J Gen Physiol. 1967 May;50(5):1327–1352. doi: 10.1085/jgp.50.5.1327. [DOI] [PMC free article] [PubMed] [Google Scholar]
  5. Duggan P. F., Martonosi A. Sarcoplasmic reticulum. IX. The permeability of sarcoplasmic reticulum membranes. J Gen Physiol. 1970 Aug;56(2):147–167. doi: 10.1085/jgp.56.2.147. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. EBASHI S. Calcium binding activity of vesicular relaxing factor. J Chir (Paris) 1961 Sep;82:236–244. doi: 10.1093/oxfordjournals.jbchem.a127439. [DOI] [PubMed] [Google Scholar]
  7. HUXLEY A. F. Muscle structure and theories of contraction. Prog Biophys Biophys Chem. 1957;7:255–318. [PubMed] [Google Scholar]
  8. HUXLEY A. F., TAYLOR R. E. Local activation of striated muscle fibres. J Physiol. 1958 Dec 30;144(3):426–441. doi: 10.1113/jphysiol.1958.sp006111. [DOI] [PMC free article] [PubMed] [Google Scholar]
  9. Harigaya S., Schwartz A. Rate of calcium binding and uptake in normal animal and failing human cardiac muscle. Membrane vesicles (relaxing system) and mitochondria. Circ Res. 1969 Dec;25(6):781–794. doi: 10.1161/01.res.25.6.781. [DOI] [PubMed] [Google Scholar]
  10. Katz A. M., Repke D. I. Sodium and potassium sensitivity of calcium uptake and calcium binding by dog cardiac microsomes. Circ Res. 1967 Nov;21(5):767–775. doi: 10.1161/01.res.21.5.767. [DOI] [PubMed] [Google Scholar]
  11. Nakamaru Y., Schwartz A. Possible control of intracellular calcium metabolism by [H+]: sarcoplasmic reticulum of skeletal and cardiac muscle. Biochem Biophys Res Commun. 1970 Nov 25;41(4):830–836. doi: 10.1016/0006-291x(70)90157-9. [DOI] [PubMed] [Google Scholar]
  12. PORTER K. R., PALADE G. E. Studies on the endoplasmic reticulum. III. Its form and distribution in striated muscle cells. J Biophys Biochem Cytol. 1957 Mar 25;3(2):269–300. doi: 10.1083/jcb.3.2.269. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Palmer R. F., Posey V. A. Ion effects on calcium accumulation by cardiac sarcoplasmic reticulum. J Gen Physiol. 1967 Sep;50(8):2085–2095. doi: 10.1085/jgp.50.8.2085. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Robinson J. D. Sodium-induced efflux of calcium from brain microsomes. Biphasic effect of sulphydryl reagents. J Neurochem. 1969 Apr;16(4):587–598. doi: 10.1111/j.1471-4159.1969.tb06858.x. [DOI] [PubMed] [Google Scholar]
  15. Sandow A. Skeletal muscle. Annu Rev Physiol. 1970;32:87–138. doi: 10.1146/annurev.ph.32.030170.000511. [DOI] [PubMed] [Google Scholar]
  16. Sreter F. A. Temperature, pH and seasonal dependence of Ca-uptake and ATPase activity of white and red muscle microsomes. Arch Biochem Biophys. 1969 Oct;134(1):25–33. doi: 10.1016/0003-9861(69)90246-x. [DOI] [PubMed] [Google Scholar]
  17. Stephens W. G. Hydrogen ion and the activation of electrically excitable membranes. Nature. 1969 Nov 8;224(5219):547–549. doi: 10.1038/224547a0. [DOI] [PubMed] [Google Scholar]
  18. Waddell W. J., Bates R. G. Intracellular pH. Physiol Rev. 1969 Apr;49(2):285–329. doi: 10.1152/physrev.1969.49.2.285. [DOI] [PubMed] [Google Scholar]
  19. Weber A. Regulatory mechanisms of the calcium transport system of fragmented rabbit sarcoplasmic rticulum. I. The effect of accumulated calcium on transport and adenosine triphosphate hydrolysis. J Gen Physiol. 1971 Jan;57(1):50–63. doi: 10.1085/jgp.57.1.50. [DOI] [PMC free article] [PubMed] [Google Scholar]