title: Potential benefits of taurine in the prevention of skeletal muscle impairment induced by disuse in the hindlimb-unloaded rat.
abstract: Hindlimb unloading (HU) in rats induces severe atrophy and a slow-to-fast phenotype transition in postural slow-twitch muscles, as occurs in human disuse conditions, such as spaceflight or bed rest. In rats, a reduction of soleus muscle weight and a decrease of cross-sectional area (CSA) were observed as signs of atrophy. An increased expression of the fast-isoform of myosin heavy chain (MHC) showed the phenotype transition. In parallel the resting cytosolic calcium concentration (restCa) was decreased and the resting chloride conductance (gCl), which regulates muscle excitability, was increased toward the values of the fast-twitch muscles. Here, we investigated the possible role of taurine, which is known to modulate calcium homeostasis and gCl, in the restoration of muscle impairment due to 14-days-HU. We found elevated taurine content and higher expression of the taurine transporter TauT in the soleus muscle as compared to the fast-twitch extensor digitorum longus (EDL) muscle of control rats. Taurine level was reduced in the HU soleus muscle, although, TauT expression was not modified. Taurine oral supplementation (5 g/kg) fully prevented this loss, and preserved resting gCl and restCa together with the slow MHC phenotype. Taurine supplementation did not prevent the HU-induced drop of muscle weight or fiber CSA, but it restored the expression of MURF-1, an atrophy-related gene, suggesting a possible early protective effect of taurine. In conclusion, taurine prevented the HU-induced phenotypic transition of soleus muscle and might attenuate the atrophic process. These findings argue for the beneficial use of taurine in the treatment of disuse-induced muscle dysfunction.
authors: Section of Pharmacology, Department of Pharmacobiology, University of Bari Aldo Moro, Via Orabona 4, 70124, Bari, Italy. spierno@farmbiol.uniba.it
authors: Sabata
authors: S
authors: Pierno
authors: Antonella
authors: A
authors: Liantonio
authors: Giulia M
authors: GM
authors: Camerino
authors: Michela
authors: M
authors: De Bellis
authors: Maria
authors: M
authors: Cannone
authors: Gianluca
authors: G
authors: Gramegna
authors: Antonia
authors: A
authors: Scaramuzzi
authors: Simonetta
authors: S
authors: Simonetti
authors: Grazia Paola
authors: GP
authors: Nicchia
authors: Davide
authors: D
authors: Basco
authors: Maria
authors: M
authors: Svelto
authors: Jean-François
authors: JF
authors: Desaphy
authors: Diana Conte
authors: DC
authors: Camerino
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D018118:Chloride Channels / Q000378:metabolism; D019417:Hindlimb Suspension; D008297:Male; D009119:Muscle Contraction; D018656:Muscle Fibers, Fast-Twitch / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D018657:Muscle Fibers, Slow-Twitch / Q000187:drug effects* / Q000378:metabolism / Q000473:pathology; D009124:Muscle Proteins / Q000096:biosynthesis; D009133:Muscular Atrophy / Q000188:drug therapy* / Q000473:pathology / Q000503:physiopathology; D018995:Myosin Heavy Chains / Q000378:metabolism; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D013654:Taurine / Q000008:administration & dosage / Q000378:metabolism / Q000494:pharmacology*; D000070584:Tripartite Motif Proteins; D044767:Ubiquitin-Protein Ligases / Q000096:biosynthesis
chemical_list: D018118:Chloride Channels; D009124:Muscle Proteins; D000070584:Tripartite Motif Proteins; D013654:Taurine; C499086:Trim63 protein, rat; D044767:Ubiquitin-Protein Ligases; D018995:Myosin Heavy Chains; D002118:Calcium