Abstract
In order to clarify the mechanism underlying the reduction of resting membrane chloride conductance (g(Cl)) during aging, the levels of mRNA encoding the principal skeletal muscle chloride channel, ClC-1, were measured. Total RNA samples isolated from tibialis anterior muscles of aged (24-29 months old) and adult (3-4 months old) rats were examined for ClC-1 expression using Northern blot analysis, and macroscopic g(Cl) was recorded from extensor digitorum longus muscle fibers from each adult and aged rat in vitro using a two intracellular microelectrode technique. Although interindividual variability was observed, aged rats exhibited a parallel reduction of both g(Cl) and ClC-1 mRNA expression as compared to adult rats. A linear correlation exists between individual values of ClC-1 mRNA and g(Cl). These results provide evidence that ClC-1 is the main determinant of sarcolemmal g(Cl) and demonstrate that the decrease of g(Cl) observed during aging is associated with a down-regulation of ClC-1 expression in muscle. Copyright (C) 1999 Federation of European Biochemical Societies.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 12-16 |
| Number of pages | 5 |
| Journal | FEBS Letters |
| Volume | 449 |
| Issue number | 1 |
| DOIs | |
| State | Published - Apr 16 1999 |
Funding
The authors wish to thank Dr. Jean-François Desaphy for helpful discussion throughout the course of the study. This work was supported by grants from the Muscular Dystrophy Association (A.L.G.) and C.E.E. No. CI1*-CT 94-0037 (D.C.C.). C.L.B. is a recipient of the Louis and Emma Benzak Neuromuscular Disease Research Fellowship from the Muscular Dystrophy Association.
Keywords
- Aging
- ClC-1 chloride channel
- Electrophysiology
- Northern blot analysis
- Skeletal muscle
ASJC Scopus subject areas
- Genetics
- Molecular Biology
- Biophysics
- Structural Biology
- Biochemistry
- Cell Biology