Skip to main content
PMC home page
The Journal of Physiology logoLink to The Journal of Physiology
. 1994 Feb 1;474(3):463–471. doi: 10.1113/jphysiol.1994.sp020037

Local control of excitation-contraction coupling in rat heart cells.

W G Wier 1, T M Egan 1, J R López-López 1, C W Balke 1
PMCID: PMC1160337  PMID: 8014907

Abstract

1. Cytosolic free calcium ion concentration ([Ca2+]i) and whole-cell L-type Ca2+ channel currents were measured during excitation-contraction (E-C) coupling in single voltage-clamped rat cardiac ventricular cells. The measurements were used to compute the total cellular efflux of calcium ions through sarcoplasmic reticulum (SR) Ca2+ release channels (FSR,rel) and the influx of Ca2+ via L-type Ca2+ channels (FICa). 2. FSR,rel was elicited by depolarizing voltage-clamp pulses 200 ms in duration to membrane potentials from -30 to +80 mV. Over this range, peak FSR,rel had a bell-shaped dependence on clamp pulse potential. In all cells, the 'gain' of the system, measured as the ratio, FSR,rel(max)/FICa(max), declined from about 16, at 0 mV, to much lower values as clamp pulse voltage was made progressively more positive. We named this phenomenon of change in gain as a function of membrane potential, 'variable gain'. At clamp pulse potentials in the range -30 to 0 mV, the gain differed from cell to cell, being constant at about 16 in some cells, but decreasing from high values (approximately 65) at -20 mV in others. 3. At clamp pulse potentials at which Ca2+ influx (FICa) was maintained, FSR,rel also had a small maintained component. When macroscopic Ca2+ influx was brief (1-2 ms, during 'tails' of FICa), FSR,rel rose rapidly to a peak after repolarization and then declined with a half-time of about 9 ms (typically). 4. The rising phase of [Ca2+]i transients could be interrupted by stopping Ca2+ influx rapidly (by voltage clamp). We therefore termed this phenomenon 'interrupted SR Ca2+ release'.(ABSTRACT TRUNCATED AT 250 WORDS)

Full text

PDF
463

Selected References

These references are in PubMed. This may not be the complete list of references from this article.

  1. Ashley R. H., Williams A. J. Divalent cation activation and inhibition of single calcium release channels from sheep cardiac sarcoplasmic reticulum. J Gen Physiol. 1990 May;95(5):981–1005. doi: 10.1085/jgp.95.5.981. [DOI] [PMC free article] [PubMed] [Google Scholar]
  2. Balke C. W., Egan T. M., Wier W. G. Processes that remove calcium from the cytoplasm during excitation-contraction coupling in intact rat heart cells. J Physiol. 1994 Feb 1;474(3):447–462. doi: 10.1113/jphysiol.1994.sp020036. [DOI] [PMC free article] [PubMed] [Google Scholar]
  3. Balke C. W., Rose W. C., Marban E., Wier W. G. Macroscopic and unitary properties of physiological ion flux through T-type Ca2+ channels in guinea-pig heart cells. J Physiol. 1992 Oct;456:247–265. doi: 10.1113/jphysiol.1992.sp019335. [DOI] [PMC free article] [PubMed] [Google Scholar]
  4. Barcenas-Ruiz L., Wier W. G. Voltage dependence of intracellular [Ca2+]i transients in guinea pig ventricular myocytes. Circ Res. 1987 Jul;61(1):148–154. doi: 10.1161/01.res.61.1.148. [DOI] [PubMed] [Google Scholar]
  5. Bers D. M., Peskoff A. Diffusion around a cardiac calcium channel and the role of surface bound calcium. Biophys J. 1991 Mar;59(3):703–721. doi: 10.1016/S0006-3495(91)82284-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  6. Beuckelmann D. J., Wier W. G. Mechanism of release of calcium from sarcoplasmic reticulum of guinea-pig cardiac cells. J Physiol. 1988 Nov;405:233–255. doi: 10.1113/jphysiol.1988.sp017331. [DOI] [PMC free article] [PubMed] [Google Scholar]
  7. Cannell M. B., Allen D. G. Model of calcium movements during activation in the sarcomere of frog skeletal muscle. Biophys J. 1984 May;45(5):913–925. doi: 10.1016/S0006-3495(84)84238-1. [DOI] [PMC free article] [PubMed] [Google Scholar]
  8. Cannell M. B., Berlin J. R., Lederer W. J. Effect of membrane potential changes on the calcium transient in single rat cardiac muscle cells. Science. 1987 Dec 4;238(4832):1419–1423. doi: 10.1126/science.2446391. [DOI] [PubMed] [Google Scholar]
  9. Cleemann L., Morad M. Role of Ca2+ channel in cardiac excitation-contraction coupling in the rat: evidence from Ca2+ transients and contraction. J Physiol. 1991 Jan;432:283–312. doi: 10.1113/jphysiol.1991.sp018385. [DOI] [PMC free article] [PubMed] [Google Scholar]
  10. Fabiato A. Calcium-induced release of calcium from the cardiac sarcoplasmic reticulum. Am J Physiol. 1983 Jul;245(1):C1–14. doi: 10.1152/ajpcell.1983.245.1.C1. [DOI] [PubMed] [Google Scholar]
  11. Fabiato A. Simulated calcium current can both cause calcium loading in and trigger calcium release from the sarcoplasmic reticulum of a skinned canine cardiac Purkinje cell. J Gen Physiol. 1985 Feb;85(2):291–320. doi: 10.1085/jgp.85.2.291. [DOI] [PMC free article] [PubMed] [Google Scholar]
  12. Fabiato A. Time and calcium dependence of activation and inactivation of calcium-induced release of calcium from the sarcoplasmic reticulum of a skinned canine cardiac Purkinje cell. J Gen Physiol. 1985 Feb;85(2):247–289. doi: 10.1085/jgp.85.2.247. [DOI] [PMC free article] [PubMed] [Google Scholar]
  13. Klein M. G., Kovacs L., Simon B. J., Schneider M. F. Decline of myoplasmic Ca2+, recovery of calcium release and sarcoplasmic Ca2+ pump properties in frog skeletal muscle. J Physiol. 1991 Sep;441:639–671. doi: 10.1113/jphysiol.1991.sp018771. [DOI] [PMC free article] [PubMed] [Google Scholar]
  14. Leblanc N., Hume J. R. Sodium current-induced release of calcium from cardiac sarcoplasmic reticulum. Science. 1990 Apr 20;248(4953):372–376. doi: 10.1126/science.2158146. [DOI] [PubMed] [Google Scholar]
  15. Mazzanti M., DeFelice L. J. Ca channel gating during cardiac action potentials. Biophys J. 1990 Oct;58(4):1059–1065. doi: 10.1016/S0006-3495(90)82448-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  16. Meissner G., Henderson J. S. Rapid calcium release from cardiac sarcoplasmic reticulum vesicles is dependent on Ca2+ and is modulated by Mg2+, adenine nucleotide, and calmodulin. J Biol Chem. 1987 Mar 5;262(7):3065–3073. [PubMed] [Google Scholar]
  17. Niggli E., Lederer W. J. Voltage-independent calcium release in heart muscle. Science. 1990 Oct 26;250(4980):565–568. doi: 10.1126/science.2173135. [DOI] [PubMed] [Google Scholar]
  18. Näbauer M., Callewaert G., Cleemann L., Morad M. Regulation of calcium release is gated by calcium current, not gating charge, in cardiac myocytes. Science. 1989 May 19;244(4906):800–803. doi: 10.1126/science.2543067. [DOI] [PubMed] [Google Scholar]
  19. Näbauer M., Morad M. Ca2(+)-induced Ca2+ release as examined by photolysis of caged Ca2+ in single ventricular myocytes. Am J Physiol. 1990 Jan;258(1 Pt 1):C189–C193. doi: 10.1152/ajpcell.1990.258.1.C189. [DOI] [PubMed] [Google Scholar]
  20. O'Neill S. C., Mill J. G., Eisner D. A. Local activation of contraction in isolated rat ventricular myocytes. Am J Physiol. 1990 Jun;258(6 Pt 1):C1165–C1168. doi: 10.1152/ajpcell.1990.258.6.C1165. [DOI] [PubMed] [Google Scholar]
  21. Orchard C. H., Eisner D. A., Allen D. G. Oscillations of intracellular Ca2+ in mammalian cardiac muscle. Nature. 1983 Aug 25;304(5928):735–738. doi: 10.1038/304735a0. [DOI] [PubMed] [Google Scholar]
  22. Rose W. C., Balke C. W., Wier W. G., Marban E. Macroscopic and unitary properties of physiological ion flux through L-type Ca2+ channels in guinea-pig heart cells. J Physiol. 1992 Oct;456:267–284. doi: 10.1113/jphysiol.1992.sp019336. [DOI] [PMC free article] [PubMed] [Google Scholar]
  23. Sham J. S., Cleemann L., Morad M. Gating of the cardiac Ca2+ release channel: the role of Na+ current and Na(+)-Ca2+ exchange. Science. 1992 Feb 14;255(5046):850–853. doi: 10.1126/science.1311127. [DOI] [PubMed] [Google Scholar]
  24. Sipido K. R., Wier W. G. Flux of Ca2+ across the sarcoplasmic reticulum of guinea-pig cardiac cells during excitation-contraction coupling. J Physiol. 1991 Apr;435:605–630. doi: 10.1113/jphysiol.1991.sp018528. [DOI] [PMC free article] [PubMed] [Google Scholar]
  25. Stern M. D. Buffering of calcium in the vicinity of a channel pore. Cell Calcium. 1992 Mar;13(3):183–192. doi: 10.1016/0143-4160(92)90046-u. [DOI] [PubMed] [Google Scholar]
  26. Stern M. D. Theory of excitation-contraction coupling in cardiac muscle. Biophys J. 1992 Aug;63(2):497–517. doi: 10.1016/S0006-3495(92)81615-6. [DOI] [PMC free article] [PubMed] [Google Scholar]
  27. Valdeolmillos M., O'Neill S. C., Smith G. L., Eisner D. A. Calcium-induced calcium release activates contraction in intact cardiac cells. Pflugers Arch. 1989 Apr;413(6):676–678. doi: 10.1007/BF00581820. [DOI] [PubMed] [Google Scholar]
  28. Wier W. G. Cytoplasmic [Ca2+] in mammalian ventricle: dynamic control by cellular processes. Annu Rev Physiol. 1990;52:467–485. doi: 10.1146/annurev.ph.52.030190.002343. [DOI] [PubMed] [Google Scholar]
  29. Wier W. G., Kort A. A., Stern M. D., Lakatta E. G., Marban E. Cellular calcium fluctuations in mammalian heart: direct evidence from noise analysis of aequorin signals in Purkinje fibers. Proc Natl Acad Sci U S A. 1983 Dec;80(23):7367–7371. doi: 10.1073/pnas.80.23.7367. [DOI] [PMC free article] [PubMed] [Google Scholar]
  30. Wier W. G., Yue D. T. Intracellular calcium transients underlying the short-term force-interval relationship in ferret ventricular myocardium. J Physiol. 1986 Jul;376:507–530. doi: 10.1113/jphysiol.1986.sp016167. [DOI] [PMC free article] [PubMed] [Google Scholar]

Articles from The Journal of Physiology are provided here courtesy of The Physiological Society

RESOURCES