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Aging‐associated down‐regulation of ClC‐1 expression in skeletal muscle: phenotypic‐independent relation to the decrease of chloride conductance
Author(s) -
Pierno Sabata,
De Luca Annamaria,
Beck Carol L.,
George Alfred L.,
Conte Camerino Diana
Publication year - 1999
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/s0014-5793(99)00202-1
Subject(s) - skeletal muscle , phenotype , conductance , chloride , chemistry , chloride channel , microbiology and biotechnology , protein expression , expression (computer science) , biophysics , biology , endocrinology , biochemistry , gene , mathematics , computer science , combinatorics , organic chemistry , programming language
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.