کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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5552476 | 1557946 | 2017 | 11 صفحه PDF | دانلود رایگان |
Previous studies in our lab have shown that tetramethylpyrazine (TMP) could effectively attenuate disuse induced muscle atrophy. In order to screening out the optimal dose of tetramethylpyrazine (TMP) for protection against disuse induced muscle atrophy in hindlimb unloading (HLU) rats, in this study, we compared effects of 4 TMP doses on muscle wet weight (MWW), the ratios of muscle wet weight/body weight (MWW/BW) and muscle wet weight/dry weight (MWW/DW), fiber type composition, as well as cross-sectional area (CSA) in soleus (SOL) muscle. Consequently, we quantified optimal dose effects on both functional properties and protein expression (calpain-1, calpain-2, calpastatin and MuRF1) in SOL and extensor digitorum longus (EDL) muscles. Data indicated that the protective potential of TMP was dose-dependent: 60Â mg/kg TMP was most effective in terms of atrophy prevention. This dose reduced SOL MWW, MWW/BW and CSA muscle loss by 60, 60 and 54% (PÂ <Â 0.001), respectively. HLU-induced slow-to-fast fiber transition was reduced by 17% (PÂ <Â 0.01). 60Â mg/kg TMP also significantly lessened the decrease of contractile force, the increase of shorting velocity and fatigability induced by HLU. Besides, it also attenuated expressions of calpain-1 (SOL â8.6%, PÂ <Â 0.05; EDL â10.9%, PÂ <Â 0.05), calpain-2 (SOL â60%, PÂ <Â 0.001; EDL â32%, PÂ <Â 0.01) and MuRF1 expression (SOL â21%, PÂ <Â 0.001; EDL â10%, PÂ <Â 0.01), promoted the expression of calpastatin by 18% (PÂ <Â 0.05) in SOL muscle. Taken together, present study demonstrated that 60Â mg/kg body weight was the optimal dose of TMP against disuse induced muscle atrophy which effectively protected muscle function by inhibiting calpain-1, calpain-2 and MuRF1 expression, promoted calpastatin expression, especially in slow-twitch muscle.
Journal: Biomedicine & Pharmacotherapy - Volume 96, December 2017, Pages 513-523