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Sodium and potassium currents in freshly isolated and in proliferating human muscle satellite cells.
Author(s) -
Hamann M,
Widmer H,
Baroffio A,
Aubry J P,
Krause R M,
Kaelin A,
Bader C R
Publication year - 1994
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.1994.sp020071
Subject(s) - electrophysiology , potassium , population , staining , biophysics , potassium channel , conductance , biology , myocyte , membrane potential , sodium , patch clamp , chemistry , microbiology and biotechnology , anatomy , neuroscience , genetics , medicine , mathematics , environmental health , organic chemistry , combinatorics
1. Human muscle satellite cells (SC) were studied either immediately after dissociation of muscle biopsies or later, as they proliferated in culture. A purification procedure combined with clonal cultures ensured that electrophysiological recordings were done in myogenic cells. Hoechst staining for the DNA attested that cells were mononucleated. 2. The goals of this study were to examine (i) whether the electrophysiological properties of freshly isolated SC resembled those of SC that proliferated in culture for several weeks, (ii) whether freezing and thawing affected these properties, and (iii) whether SC constituted a homogeneous population. 3. We found that there were only subtle differences between the electrophysiological results obtained in freshly isolated SC and in proliferating SC with or without previous freezing and thawing. Most SC expressed two voltage‐gated currents, a TTX‐resistant Na+ current and a calcium‐activated potassium current (IK, Ca). 4. The level of expression of the Na+ current and of IK, Ca was affected in a different way by cellular proliferation; the normalized Na+ conductance (pS pF‐1) of proliferating cells resembled that of freshly isolated SC, whereas the IK, Ca conductance increased 10 times. The analysis of the amplitude distributions of the Na+ current and of IK, Ca in the various SC preparations suggested that there was only one class of SC.