Abstract
Changes in volume of crayfish single muscle fibers in response to changes in ionic or electrical conditions have been studied in conjunction with electrophysiological measurements and electron microscopic examinations. The occurrence of at least three mechanisms of water movements is revealed, two being processes which are superimposed on the normal osmotic water movement that results from a change in the concentration of solute in the medium. Differences between the time courses of the changes in volume and potential on changing Ki/Ko indicate that water may be distributed unequally for a time within compartments of the fiber. Electron micrographs reveal a selective accumulation of water at the periphery of the fiber under certain conditions. A correlation of H2O transfer with a change in membrane potential is apparent in crayfish muscle fibers and is probably due to electroosmotic effects. Electrokinetic water movements are produced whenever the membrane potential is changed to a considerable degree by changing the level of K and/or Cl in the medium, or by applying currents with an intracellular microelectrode. Depolarizations cause shrinkage. Hyperpolarizations or repolarizations cause swelling. The volume changes are independent of the occurrence or absence of swelling in the anion-permselective transverse tubular system. They indicate that the fiber membrane along the surface is heterogeneous, not only with respect to the signs of its fixed charge sites, but also with respect to the sizes and relative permselectivities of these charged channels.
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Selected References
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- ADRIAN R. H. Potassium chloride movement and the membrane potential of frog muscle. J Physiol. 1960 Apr;151:154–185. [PMC free article] [PubMed] [Google Scholar]
- CHARLEY P., SALTMAN P. Chelation of calcium by lactose: its role in transport mechanisms. Science. 1963 Mar 22;139(3560):1205–1206. doi: 10.1126/science.139.3560.1205. [DOI] [PubMed] [Google Scholar]
- 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]
- DIAMOND J. M. The mechanism of water transport by the gall-bladder. J Physiol. 1962 May;161:503–527. doi: 10.1113/jphysiol.1962.sp006900. [DOI] [PMC free article] [PubMed] [Google Scholar]
- Finkelstein A., Mauro A. Equivalent Circuits as Related to Ionic Systems. Biophys J. 1963 May;3(3):215–237. doi: 10.1016/s0006-3495(63)86817-4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GARRELS R. M., SATO M., THOMPSON M. E., TRUESDELL A. H. Glass electrodes sensitive to divalent cations. Science. 1962 Mar 23;135(3508):1045–1048. doi: 10.1126/science.135.3508.1045. [DOI] [PubMed] [Google Scholar]
- GIRARDIER L., REUBEN J. P., BRANDT P. W., GRUNDFEST H. EVIDENCE FOR ANION-PERMSELECTIVE MEMBRANE IN CRAYFISH MUSCLE FIBERS AND ITS POSSIBLE ROLE IN EXCITATION-CONTRACTION COUPLING. J Gen Physiol. 1963 Sep;47:189–214. doi: 10.1085/jgp.47.1.189. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GRIM E., SOLLNER K. The contributions of normal and anomalous osmosis to the osmotic effects arising across charged membranes with solutions of electrolytes. J Gen Physiol. 1957 Jul 20;40(6):887–899. doi: 10.1085/jgp.40.6.887. [DOI] [PMC free article] [PubMed] [Google Scholar]
- GRIM E., SOLLNER K. True anomalous osmosis in multi-solute model membrane systems. J Gen Physiol. 1960 Nov;44:381–392. doi: 10.1085/jgp.44.2.381. [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]
- KEDEM O., KATCHALSKY A. A physical interpretation of the phenomenological coefficients of membrane permeability. J Gen Physiol. 1961 Sep;45:143–179. doi: 10.1085/jgp.45.1.143. [DOI] [PMC free article] [PubMed] [Google Scholar]
- NEIHOF R., SOLLNER K. A quantitative electrochemical theory of the electrolyte permeability of mosaic membranes composed of selectively anion-permeable and selectively cation-permeable parts, and its experimental verification. II. A quantitative test of the theory in model systems which do not involve the use of auxiliary electrodes. J Gen Physiol. 1955 May 20;38(5):613–622. doi: 10.1085/jgp.38.5.613. [DOI] [PMC free article] [PubMed] [Google Scholar]
- REUBER J. P., LOPEZ E., BRANDT P. W., GRUNDFEST H. MUSCLE: VOLUME CHANGES IN ISOLATED SINGLE FIBERS. Science. 1963 Oct 11;142(3589):246–248. doi: 10.1126/science.142.3589.246. [DOI] [PubMed] [Google Scholar]