Aging‐associated down‐regulation of ClC‐1 expression in skeletal muscle: phenotypic‐independent relation to the decrease of chloride conductance

FEBS Letters

George, Alfred L.¹  Pierno, Sabata²  Beck, Carol L.¹  De Luca, Annamaria²  Conte Camerino, Diana² 

[1] Departments of Medicine and Pharmacology, Vanderbilt University School of Medicine, Nashville, TN 37232-2372, USA;Unit of Pharmacology, Department of Pharmacobiology, Faculty of Pharmacy, University of Bari, Via Orabona 4, I-70125 Bari, Italy

关键词: Aging;    Skeletal muscle;    Electrophysiology;    ClC-1 chloride channel;    Northern blot analysis;    g Cl;    resting membrane chloride conductance;    ClC-1;    muscular chloride channel-1;    9-AC;    9-anthracene carboxylic acid;    EDL;    extensor digitorum longus;    TA;    tibialis anterior;    UV;    ultraviolet;    G6PD;    glucose 6-phosphate dehydrogenase;    Rm;    membrane resistance;    g m;    total membrane conductance;    g K;    resting membrane potassium conductance;    R;    rheobase voltage;   

DOI  :  10.1016/S0014-5793(99)00202-1

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

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.

【 授权许可】

Unknown