Fiber type-related changes in rat skeletal muscle calcium homeostasis during aging and restoration by growth hormone

Neurobiology of Disease

Daniela Cocchi¹  Claudia Camerino²  Jean-François Desaphy³  Antonella Liantonio³  Diana Conte Camerino³  Bodvael Fraysse³  Jean-François Rolland³  Annamaria De Luca³  Viviana Giannuzzi³  Sabata Pierno³  M. Paola Didonna³ 

[1] Department of Biomedical Sciences and Biotechnology, Faculty of Medicine, University of Brescia, Brescia I-25124, Italy;Department of Human Anatomy and Histology, Faculty of Medicine, University of Bari, Bari I-70125, Italy;Division of Pharmacology, Department of Pharmaco-Biology, Faculty of Pharmacy, University of Bari, Bari I-70125, Italy;

关键词: Aging;    Skeletal muscle;    Resting calcium concentration;    Fura-2;    Growth hormone;    Sarcolemmal permeability to calcium;   

DOI  :  

来源: DOAJ

【 摘 要 】

The mechanisms by which aging induces muscle impairment are not well understood yet. We studied the impact of aging on Ca2+ homeostasis in the slow-twitch soleus and the fast-twitch extensor digitorum longus (EDL) muscles of aged rats by using the fura-2 fluorescent probe. In both muscles aging increases the resting cytosolic calcium concentration ([Ca2+]i). This effect was independent on calcium influx since a reduced resting permeability of sarcolemma to divalent cations was observed in aged muscles likely due to a reduced activity of leak channels. Importantly the effects of aging on resting [Ca2+]i, fiber diameter, mechanical threshold and sarcolemmal resting conductances were less pronounced in the soleus muscle, suggesting that muscle impairment may be less dependent on [Ca2+]i in the slow-twitch muscle. The treatment of aged rats with growth hormone restored the resting [Ca2+]i toward adult values in both muscles. Thus, an increase of resting [Ca2+]i may contribute to muscle weakness associated with aging and may be considered for developing new therapeutic strategies in the elderly.

【 授权许可】

Unknown