The passive electrical properties of glycerol-treated muscle fibers, which have virtually no transverse tubules, were determined. Current was passed through one intracellular microelectrode and the time course and spatial distribution of the resulting potential displacement measured with another. The results were analyzed by using conventional cable equations. The membrane resistance of fibers without tubules was 3759 ± 331 ohm-cm2 and the internal resistivity 192 ohm-cm. Both these figures are essentially the same as those found in normal muscle fibers. The capacitance of the fibers without tubules is strikingly smaller than normal, being 2.24 ± 0.14 µF/cm2. Measurements were also made of the passive electrical properties of fibers in a Ringer solution containing 400 mM glycerol (which is used in the preparation of glycerol-treated fibers). The membrane resistance and capacitance are essentially normal, but the internal resistivity is somewhat reduced. These results show that glycerol in this concentration does not directly affect the membrane capacitance. Thus, the figure for the capacitance of glycerol-treated fibers, which agrees well with previous estimates made by different techniques, represents the capacitance of the outer membrane of the fiber. Estimates of the capacitance per unit area of the tubular membrane are made and the significance of the difference between the figures for the capacitance of the surface and tubular membrane is discussed.
Article|
March 01 1969
Capacitance of the Surface and Transverse Tubular Membrane of Frog Sartorius Muscle Fibers
Peter W. Gage,
Peter W. Gage
From the Department of Physiology, Duke University, Durham, North Carolina 27706.
Search for other works by this author on:
Robert S. Eisenberg
Robert S. Eisenberg
From the Department of Physiology, Duke University, Durham, North Carolina 27706.
Search for other works by this author on:
Peter W. Gage
From the Department of Physiology, Duke University, Durham, North Carolina 27706.
Robert S. Eisenberg
From the Department of Physiology, Duke University, Durham, North Carolina 27706.
Dr. Gage's present address is Department of Physiology, University of New South Wales, Kensington, Australia. Dr. Eisenberg's present address is Department of Physiology, University of California at Los Angeles, Los Angeles, California 90024
Received:
October 25 1968
Online ISSN: 1540-7748
Print ISSN: 0022-1295
Copyright © 1969 by The Rockefeller University Press
1969
J Gen Physiol (1969) 53 (3): 265–278.
Article history
Received:
October 25 1968
Citation
Peter W. Gage, Robert S. Eisenberg; Capacitance of the Surface and Transverse Tubular Membrane of Frog Sartorius Muscle Fibers . J Gen Physiol 1 March 1969; 53 (3): 265–278. doi: https://doi.org/10.1085/jgp.53.3.265
Download citation file: