Loureiro Adriano César Carneiro, do Rêgo-Monteiro Igor Coutinho, Louzada Ruy A, Ortenzi Victor Hugo, de Aguiar Angélica Ponte, de Abreu Ewerton Sousa, Cavalcanti-de-Albuquerque João Paulo Albuquerque, Hecht Fabio, de Oliveira Ariclécio Cunha, Ceccatto Vânia Marilande, Fortunato Rodrigo S, Carvalho Denise P
Laboratório de Expressão Gênica, Instituto Superior de Ciências Biomédicas, Universidade Estadual do Ceará, Fortaleza, CE, Brazil.
Laboratório de Radiobiologia Molecular, Instituto de Biofísica Carlos Chagas Filho, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ, Brazil.
Oxid Med Cell Longev. 2016;2016:6738701. doi: 10.1155/2016/6738701. Epub 2016 Oct 26.
NADPH oxidases (NOX) are important sources of reactive oxygen species (ROS) in skeletal muscle, being involved in excitation-contraction coupling. Thus, we aimed to investigate if NOX activity and expression in skeletal muscle are fiber type specific and the possible contribution of this difference to cellular oxidative stress. Oxygen consumption rate, NOX activity and mRNA levels, and the activity of catalase (CAT), glutathione peroxidase (GPX), and superoxide dismutase (SOD), as well as the reactive protein thiol levels, were measured in the soleus (SOL), red gastrocnemius (RG), and white gastrocnemius (WG) muscles of rats. RG showed higher oxygen consumption flow than SOL and WG, while SOL had higher oxygen consumption than WG. SOL showed higher NOX activity, as well as NOX2 and NOX4 mRNA levels, antioxidant enzymatic activities, and reactive protein thiol contents when compared to WG and RG. NOX activity and NOX4 mRNA levels as well as antioxidant enzymatic activities were higher in RG than in WG. Physical exercise increased NOX activity in SOL and RG, specifically NOX2 mRNA levels in RG and NOX4 mRNA levels in SOL. In conclusion, we demonstrated that NOX activity and expression differ according to the skeletal muscle fiber type, as well as antioxidant defense.
NADPH氧化酶（NOX）是骨骼肌中活性氧（ROS）的重要来源，参与兴奋-收缩偶联。因此，我们旨在研究骨骼肌中NOX的活性和表达是否具有纤维类型特异性，以及这种差异对细胞氧化应激的可能影响。我们测定了大鼠比目鱼肌（SOL）、红色腓肠肌（RG）和白色腓肠肌（WG）的耗氧率、NOX活性和mRNA水平，以及过氧化氢酶（CAT）、谷胱甘肽过氧化物酶（GPX）和超氧化物歧化酶（SOD）的活性，还有活性蛋白巯基水平。RG的耗氧流量高于SOL和WG，而SOL的耗氧量高于WG。与WG和RG相比，SOL的NOX活性、NOX2和NOX4 mRNA水平、抗氧化酶活性以及活性蛋白巯基含量更高。RG的NOX活性、NOX4 mRNA水平以及抗氧化酶活性高于WG。体育锻炼增加了SOL和RG中的NOX活性，特别是RG中的NOX2 mRNA水平和SOL中的NOX4 mRNA水平。总之，我们证明了NOX的活性和表达因骨骼肌纤维类型以及抗氧化防御的不同而存在差异。
