Abstract
In frog fast skeletal muscle, we find a decline of twitch, tetanus, and maximum K and caffeine contracture tensions as tonicity of the bathing solution is increased. The decline of tension independent of the method of producing contraction indicates that the major effect of hypertonicity is directly on contractile tension probably because of the increased internal ionic strength. However, there is some apparent disruption of excitation-contraction (E-C) coupling in solutions made three times the normal tonicity (3T solutions) since: (a) in 3T solutions tetanic and K contracture tensions decline to zero from a value near the average maximum caffeine contracture tension at this tonicity (10% of 1T tetanic tension). At this time, caffeine contractures of 10% of 1T tetanic tension can be elicited; (b) once the K contracture tension has declined, elevated [Ca++]o, 19.8 mM, restores K contracture tension to 13% of 1T tetanic tension. This probable disruption is not caused by changes in mechanical threshold since in 2T solutions the mechanical threshold is shifted by 12 mv in the hyperpolarizing direction. This is consistent with neutralization of fixed negative charges on the inside of the membrane. The repriming curve is also shifted in the hyperpolarizing direction in 2T solutions. Shifts of the repriming curve coupled with membrane depolarizations in 3T solutions (about 20 mv) may produce loss of repriming ability at the resting potential and disruption of E-C coupling.
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Selected References
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- April E., Brandt P. W., Reuben J. P., Grundfest H. Muscle contraction: the effect of ionic strength. Nature. 1968 Oct 12;220(5163):182–184. doi: 10.1038/220182a0. [DOI] [PubMed] [Google Scholar]
- BAKER P. F., HODGKIN A. L., MEVES H. THE EFFECT OF DILUTING THE INTERNAL SOLUTION ON THE ELECTRICAL PROPERTIES OF A PERFUSED GIANT AXON. J Physiol. 1964 Apr;170:541–560. doi: 10.1113/jphysiol.1964.sp007348. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caputo C. Caffeine- and potassium-induced contractures of frog striated muscle fibers in hypertonic solutions. J Gen Physiol. 1966 Sep;50(1):129–139. doi: 10.1085/jgp.50.1.129. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Caputo C. Volume and twitch tension changes in single muscle fibers in hypertonic solutions. J Gen Physiol. 1968 Nov;52(5):793–809. doi: 10.1085/jgp.52.5.793. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Carvalho A. P. Binding of cations by microsomes from rabbit skeletal muscle. J Cell Physiol. 1966 Feb;67(1):73–83. doi: 10.1002/jcp.1040670109. [DOI] [PubMed] [Google Scholar]
- Chandler W. K., Hodgkin A. L., Meves H. The effect of changing the internal solution on sodium inactivation and related phenomena in giant axons. J Physiol. 1965 Oct;180(4):821–836. doi: 10.1113/jphysiol.1965.sp007733. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FUJINO M., YAMAGUCHI T., SUZUKI K. 'Glycerol effect' and the mechanism linking excitation of the plasma membrane with contraction. Nature. 1961 Dec 23;192:1159–1161. doi: 10.1038/1921159a0. [DOI] [PubMed] [Google Scholar]
- FUJINO S., FUJINO M. REMOVAL OF THE INHIBITORY EFFECT OF HYPERTONIC SOLUTIONS ON THE CONTRACTIBILITY IN MUSCLE CELLS AND THE EXCITATION-CONTRACTION LINK. Nature. 1964 Mar 28;201:1331–1333. doi: 10.1038/2011331a0. [DOI] [PubMed] [Google Scholar]
- Freygang W. H., Jr, Rapoport S. I., Peachey L. D. Some relations between changes in the linear electrical properties of striated muscle fibers and changes in ultrastructure. J Gen Physiol. 1967 Nov;50(10):2437–2458. doi: 10.1085/jgp.50.10.2437. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Geduldig D. Analysis of membrane permeability coefficient ratios and internal ion concentrations from a constant field equation. J Theor Biol. 1968 Apr;19(1):67–78. doi: 10.1016/0022-5193(68)90005-2. [DOI] [PubMed] [Google Scholar]
- HODGKIN A. L., HOROWICZ P. Potassium contractures in single muscle fibres. J Physiol. 1960 Sep;153:386–403. doi: 10.1113/jphysiol.1960.sp006541. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HODGKIN A. L., HOROWICZ P. The influence of potassium and chloride ions on the membrane potential of single muscle fibres. J Physiol. 1959 Oct;148:127–160. doi: 10.1113/jphysiol.1959.sp006278. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Hill D. K. Tension due to interaction between the sliding filaments in resting striated muscle. The effect of stimulation. J Physiol. 1968 Dec;199(3):637–684. doi: 10.1113/jphysiol.1968.sp008672. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Lorković H. The influence of ionic strength on potassium contractures and calcium movements in frog muscle. J Gen Physiol. 1967 Mar;50(4):883–891. doi: 10.1085/jgp.50.4.883. [DOI] [PMC free article] [PubMed] [Google Scholar]
- MARTONOSI A., FERETOS R. SARCOPLASMIC RETICULUM. I. THE UPTAKE OF CA++ BY SARCOPLASMIC RETICULUM FRAGMENTS. J Biol Chem. 1964 Feb;239:648–658. [PubMed] [Google Scholar]
- Sandow A. Excitation-contraction coupling in skeletal muscle. Pharmacol Rev. 1965 Sep;17(3):265–320. [PubMed] [Google Scholar]
- TIGYI J., SHIH-FANG F. The effect of hypertonic solution on the contraction, resting- and action potential of the muscle fibre. Acta Physiol Acad Sci Hung. 1962;22:293–295. [PubMed] [Google Scholar]
- WEBER A., HERZ R. The binding of calcium to actomyosin systems in relation to their biological activity. J Biol Chem. 1963 Feb;238:599–605. [PubMed] [Google Scholar]
- Weber A., Herz R. The relationship between caffeine contracture of intact muscle and the effect of caffeine on reticulum. J Gen Physiol. 1968 Nov;52(5):750–759. doi: 10.1085/jgp.52.5.750. [DOI] [PMC free article] [PubMed] [Google Scholar]