Abstract
Potassium contractures were induced in lobster muscle bundles under conditions which produced varying KCl fluxes into the fibers. The presence or absence of chloride fluxes during depolarization by high concentrations of potassium, had no effect on the tensions developed. The curve relating tension to the membrane potential had a typical sigmoid shape with an apparent "threshold" for tension at -60 mv. Soaking the muscles in low (0.1 mM) calcium salines for 30 min completely eliminated the potassium contractures but the caffeine contractures were only slightly reduced under these conditions. The potassium contracture could be completely restored in less than 2 min by return of the calcium ions to the saline. Evidence is presented for independent, superficial, and deep calcium sites; the superficial sites appear to be involved in the coupling mechanisms associated with potassium contractures. These sites are highly selective for Ca++, and attempts to substitute either Cd++, Co++, Mg++, Ba++, or Sr++ for Ca++ were unsuccessful. However, K+ appeared to compete with Ca++ for these sites, and the evoked tension could be reduced by prestimulation of the muscle fibers with high K+ salines. The results of studies on the influx of 45Ca during potassium contractures were compatible with the view of muscle activation by the entry of extracellular calcium.
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Selected References
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- AXELSSON J., THESLEFF S. Activation of the contractile mechanism in striated muscle. Acta Physiol Scand. 1958 Oct 28;44(1):55–66. doi: 10.1111/j.1748-1716.1958.tb01608.x. [DOI] [PubMed] [Google Scholar]
- Ashley C. C. The role of cell calcium in the contraction of single cannulated muscle fibers. Am Zool. 1967 Aug;7(3):647–659. doi: 10.1093/icb/7.3.647. [DOI] [PubMed] [Google Scholar]
- BIANCHI C. P., SHANES A. M. Calcium influx in skeletal muscle at rest, during activity, and during potassium contracture. J Gen Physiol. 1959 Mar 20;42(4):803–815. doi: 10.1085/jgp.42.4.803. [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]
- 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]
- EDWARDS C., CHICHIBU S., HAGIWARA S. RELATION BETWEEN MEMBRANE POTENTIAL CHANGES AND TENSION IN BARNACLE MUSCLE FIBERS. J Gen Physiol. 1964 Nov;48:225–234. doi: 10.1085/jgp.48.2.225. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Edwards C., Lorkovic H. The roles of calcium in excitation-contraction coupling in various muscles of the frog, mouse, and barnacle. Am Zool. 1967 Aug;7(3):615–622. doi: 10.1093/icb/7.3.615. [DOI] [PubMed] [Google Scholar]
- FALK G., FATT P. LINEAR ELECTRICAL PROPERTIES OF STRIATED MUSCLE FIBRES OBSERVED WITH INTRACELLULAR ELECTRODES. Proc R Soc Lond B Biol Sci. 1964 Apr 14;160:69–123. doi: 10.1098/rspb.1964.0030. [DOI] [PubMed] [Google Scholar]
- FRANK G. B. Effects of changes in extracellular calcium concentration on the potassium-induced contracture of frog's skeletal muscle. J Physiol. 1960 Jun;151:518–538. doi: 10.1113/jphysiol.1960.sp006457. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FRANK G. B. Utilization of bound calcium in the action of caffeine and certain multivalent cations on skeletal muscle. J Physiol. 1962 Sep;163:254–268. doi: 10.1113/jphysiol.1962.sp006972. [DOI] [PMC free article] [PubMed] [Google Scholar]
- FUJINO M., FUJINO S. SELECTIVE INHIBITION OF POTASSIUM CONTRACTURE IN PRESENCE OF INTACT TWITCH. J Gen Physiol. 1964 Jul;47:1079–1088. doi: 10.1085/jgp.47.6.1079. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Gainer H., Grundfest H. Permeability of alkali metal cations in lobster muscle. A comparison of electrophysiological and osmometric analyses. J Gen Physiol. 1968 Mar;51(3):399–425. doi: 10.1085/jgp.51.3.399. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HASSELBACH W. RELAXATION AND THE SARCOTUBULAR CALCIUM PUMP. Fed Proc. 1964 Sep-Oct;23:909–912. [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 effect of sudden changes in ionic concentrations on the membrane potential of single muscle fibres. J Physiol. 1960 Sep;153:370–385. doi: 10.1113/jphysiol.1960.sp006540. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HOYLE G., SMYTH T., Jr NEUROMUSCULAR PHYSIOLOGY OF GIANT MUSCLE FIBERS OF A BARNACLE, BALANUS NUBILUS DARWIN. Comp Biochem Physiol. 1963 Dec;10:291–314. doi: 10.1016/0010-406x(63)90229-9. [DOI] [PubMed] [Google Scholar]
- JENDEN D. J., REGER J. F. THE ROLE OF RESTING POTENTIAL CHANGES IN THE CONTRACTILE FAILURE OF FROG SARTORIUS MUSCLES DURING CALCIUM DEPRIVATION. J Physiol. 1963 Dec;169:889–901. doi: 10.1113/jphysiol.1963.sp007302. [DOI] [PMC free article] [PubMed] [Google Scholar]
- KIKU-IRI T. DISSOCIATION OF ELECTRICAL AND MECHANICAL EVENTS IN DENERVATED FROG SKELETAL MUSCLE. Jpn J Physiol. 1964 Aug 15;14:400–410. doi: 10.2170/jjphysiol.14.400. [DOI] [PubMed] [Google Scholar]
- Lorković H. Effects of some divalent cations on frog twitch muscles. Am J Physiol. 1967 Mar;212(3):623–628. doi: 10.1152/ajplegacy.1967.212.3.623. [DOI] [PubMed] [Google Scholar]
- ORKAND R. K. The relation between membrane potential and contraction in single crayfish muscle fibres. J Physiol. 1962 Apr;161:143–159. doi: 10.1113/jphysiol.1962.sp006878. [DOI] [PMC free article] [PubMed] [Google Scholar]
- PARRISH R. G., MOMMAERTS W. F. Studies on myosin. II. Some molecular-kinetic data. J Biol Chem. 1954 Aug;209(2):901–913. [PubMed] [Google Scholar]
- PORTZEHL H., CALDWELL P. C., RUEEGG J. C. THE DEPENDENCE OF CONTRACTION AND RELAXATION OF MUSCLE FIBRES FROM THE CRAB MAIA SQUINADO ON THE INTERNAL CONCENTRATION OF FREE CALCIUM IONS. Biochim Biophys Acta. 1964 May 25;79:581–591. doi: 10.1016/0926-6577(64)90224-4. [DOI] [PubMed] [Google Scholar]
- Reuben J. P., Brandt P. W., Garcia H., Grundfest H. Excitation-contraction coupling in crayfish. Am Zool. 1967 Aug;7(3):623–645. doi: 10.1093/icb/7.3.623. [DOI] [PubMed] [Google Scholar]
- Sandow A. Excitation-contraction coupling in skeletal muscle. Pharmacol Rev. 1965 Sep;17(3):265–320. [PubMed] [Google Scholar]
- Van der Kloot W. G., Glovsky J. The uptake of Ca2+ and Sr2+ by fractions from lobster muscle. Comp Biochem Physiol. 1965 Aug;15(4):547–565. doi: 10.1016/0010-406x(65)90154-4. [DOI] [PubMed] [Google Scholar]
- Zachar J., Zacharová D. Potassium contractures in single muscle fibres of the crayfish. J Physiol. 1966 Oct;186(3):596–618. doi: 10.1113/jphysiol.1966.sp008058. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Zacharová D., Zachar J. The effect of external calcium ions on the excitation-contraction coupling in single muscle fibres of the crayfish. Physiol Bohemoslov. 1967;16(3):191–207. [PubMed] [Google Scholar]