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The effect of diameter on the electrical constants of frog skeletal muscle fibres
Author(s) -
Hodgkin A. L.,
Nakajima S.
Publication year - 1972
Publication title -
the journal of physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.802
H-Index - 240
eISSN - 1469-7793
pISSN - 0022-3751
DOI - 10.1113/jphysiol.1972.sp009742
Subject(s) - conductance , electrical resistivity and conductivity , membrane , chemistry , materials science , analytical chemistry (journal) , transverse plane , biophysics , anatomy , condensed matter physics , chromatography , physics , biology , biochemistry , quantum mechanics
1. Electrical constants were determined on isolated single fibres or on fibres from bundles from frog's twitch muscles by analysing the low frequency cable properties. 2. The sarcoplasmic conductivity ( G i ) was 5·9 mmho/cm at 20° C, and its temperature coefficient ( Q 10 ) was 1·37. 3. The Q 10 of the membrane conductance ( G M ) was 1·49, and that of the membrane capacity ( C M ) was 1·02. 4. C M increases with diameter ( D ) in an approximately linear manner: the values were 4·6 μF/cm 2 at D = 50 μ, and 8·5 μF/cm 2 at D = 130 μ. 5. G M also increases with diameter, being 0·21 mmho/cm 2 at D = 50 μ and 0·37 mmho/cm 2 at D = 130 μ. 6. These results suggest that the transverse tubular system contributes substantially to the values of low frequency capacity and conductance measured at the surface membrane.