Zohreh Shanazari; Mohammad Faramarzi; Mohammadreza kordi
Abstract
Background and Aim: Muscle atrophy is an active process controlled by specific signaling pathways and transcriptional programs. Atrogin-1/MAFbx and MuRF1 are up-regulated in different models of muscle atrophy and is responsible for increased protein degradation through the ubiquitin proteasome pathway. ...
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Background and Aim: Muscle atrophy is an active process controlled by specific signaling pathways and transcriptional programs. Atrogin-1/MAFbx and MuRF1 are up-regulated in different models of muscle atrophy and is responsible for increased protein degradation through the ubiquitin proteasome pathway. The purpose of this study was to investigate the effect of moderate and high intensity resistance training on miR-23a, Atrogin-1 and MuRF gene expression in fast and slow twitch muscles in elderly rats. Materials and Methods: Thirty male Wistar rats (23 months old) were randomly divided into three groups (n=10) including moderate-intensity resistance training, high-intensity resistance training and the control groups. Resistance training were performed during eight weeks of climbing a ladder with high intensity (80% Maximum voluntary carrying capacity/MVCC) and moderate intensity (60% of MVCC) for 5 days a week. Isolation of Soleus muscle and Flexor halluces longus (FHL) was performed immediately after blood sampling in sterile conditions. MiR-23a, Atrogin-1 and MuRF expression were measured by RT-PCR method in Soleus and FHL muscles. The statistical analysis was performed by One-way & Two-way ANOVA tests with significance level of p<0.05. Results: The results showed that the expression of MuRF and Atrogin-1 genes in both resistance groups were significantly lower than those the control group and miR-23a expression expression in both high and moderate resistance groups was significantly higher than the control group (p<0.05). But there was no significant difference between the effect of high and moderate intensity resistance training on miR-23a, MuRF, and Atrogin-1 expression in both muscles (p>0.05). Conclusion: It seems that resistance training with moderate and high-intensity can decrease the resting levels and gene expression of factors associated with muscular atrophy (miR-23a) and its target genes (Atrogin-1, MuRF) in older rats, and these exercises could lead to the prevention of sarcopenia.
Shirin Banitalebi dehkordi; Mohammad Faramarzi; Mostafa Rahimi; Afrasiab Sadeghi
Abstract
Background and Aim: Beach soccer as a new exciting and popular field of sport is spreading rapidly around the world. However, so far, limited accurate and documented information is available about the physical and physiological needs of this sport. The purpose of this study was to investigate the changes ...
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Background and Aim: Beach soccer as a new exciting and popular field of sport is spreading rapidly around the world. However, so far, limited accurate and documented information is available about the physical and physiological needs of this sport. The purpose of this study was to investigate the changes in resting levels of some inflammatory, muscle damage, aerobic and anaerobic indices of beach soccer players in the pre-season, mid-season and end of the premier league season. Materials and Methods: In this quasi-experimental study with repeated measures design, 13 elite beach soccer players (Mean± SD: age 24.64±4.01 year, body mass index 22.76±2.36 kg/m2 and maximum oxygen consumption 38.60±5.48 ml/kg/min) were selected. Measurements of aerobic and anaerobic power and alanin amino teransferase (ALT), aspartat amino teransferse (AST), certain phosphokinase (CPK) and lactate dehydrogenase (LDH) indices were measured in the 98-99 pro league in pre-season, mid-season and also at the end of the season. The repeated measure analysis of variance and Bonferroni tests were used to examine the changes at the significant level of p<0.05. Results: Significant increase in ALT (p=0.04) and also decrease in anaerobic power (p=0.001) was observed from pre-season to the end of the season. LDH levels showed a significant increase in the mid-season compared to the pre-season (p=0.04) and as the same the significant decrease also was found at the end of the season compared to the mid-season (p=0.01). However, no significant changes were observed in AST (p=0.50), CPK (p=0.15) and aerobic power (p=0.11) during the competition season. Conclusion: Due to the physiological pressure for beach soccer players at different stages, it is recommended that players in this field should be monitored for biochemical and functional parameters during the competition season, and based on that, training, nutrition and recovery programs could be optimized.
