Premium
Influence of various growth factors and conditions on development of resting membrane potential and its electrogenic pump component of cultured rat skeletal myotubes
Author(s) -
Brodie Chaya,
Sampson S.R.
Publication year - 1986
Publication title -
international journal of developmental neuroscience
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.761
H-Index - 88
eISSN - 1873-474X
pISSN - 0736-5748
DOI - 10.1016/0736-5748(86)90050-x
Subject(s) - myogenesis , component (thermodynamics) , microbiology and biotechnology , membrane potential , chemistry , biophysics , membrane , biology , myocyte , biochemistry , physics , thermodynamics
The effects of different growth factors and growth conditions were studied on the development of resting membrane potential and its electrogenic—ouabain‐sensitive—pump component in cultured rat myotubes. Resting potential and its electrogenic pump component were dependent on the initial plating density of the myotubes, both values increasing with increasing density. Medium from cells plated at high density, when used to replace the medium of low density cells, increased both the resting potential and its electrogenic pump component of low density myotubes. Treatment of myotubes with cytosine‐arabinoside delayed the appearance of [ 3 H]ouabain binding sites and electrogenic pump component of resting potential, but by 8 days in culture there was no difference between treated and control cells. Similarly, cells plated initially in 5% horse serum developed resting potential and its electrogenic pump component more slowly than those in 15% horse serum, but by 8–10 days in vitro , the differences were no longer apparent. Chick embryo extract was found to have little, if any, influence on development of resting potential and its electrogenic pump component. We conclude that the different growth conditions and factors to the extent that they influence membrane potential, do so by altering the time of appearance of Na‐K ATPase, the activity of which contributes a considerable component to resting potential.