de Sousa Neto Ivo V, Durigan João L Q, Guzzoni Vinicius, Tibana Ramires A, Prestes Jonato, de Araujo Heloisa S Selistre, Marqueti Rita de Cássia
Graduate Program of Sciences and Technology of Health, University of Brasilia, Brasília, Brazil.
Department of Physiological Sciences, Federal University of São Carlos, São Carlos, Brazil.
Front Physiol. 2018 Mar 12;9:190. doi: 10.3389/fphys.2018.00190. eCollection 2018.
Aging is a complex, multifactorial process characterized by the accumulation of deleterious effects, including biochemical adaptations of the extracellular matrix (ECM). The purpose of this study was to investigate the effects of 12 weeks of resistance training (RT) on metalloproteinase 2 (MMP-2) activity in skeletal muscles and, MMP-2 and MMP-9 activity in the blood circulation of young and old rats. Twenty-eight Wistar rats were randomly divided into four groups ( = 7 per group): young sedentary (YS); young trained (YT), old sedentary (OS), and old trained (OT). The stair climbing RT consisted of one training session every 2 other day, with 8-12 dynamic movements per climb. The animals were euthanized 48 h after the end of the experimental period. MMP-2 and MMP-9 activity was measured by zymography. There was higher active MMP-2 activity in the lateral gastrocnemius and flexor digitorum profundus muscles in the OT group when compared to the OS, YS, and YT groups ( ≤ 0.001). Moreover, there was higher active MMP-2 activity in the medial gastrocnemius muscle in the OT group when compared to the YS and YT groups ( ≤ 0.001). The YS group presented lower active MMP-2 activity in the soleus muscle than the YT, OS, OT groups ( ≤ 0.001). With respect to active MMP-2/9 activity in the bloodstream, the OT group displayed significantly reduced activity ( ≤ 0.001) when compared to YS and YT groups. In conclusion, RT up-regulates MMP-2 activity in aging muscles, while down-regulating MMP-2 and MMP-9 in the blood circulation, suggesting that it may be a useful tool for the maintenance of ECM remodeling.
衰老 是一个复杂的多因素过程，其特征是有害影响的积累，包括细胞外基质（ECM）的生化适应。本研究的目的是调查12周抗阻训练（RT）对年轻和老年大鼠骨骼肌中基质金属蛋白酶2（MMP-2）活性以及血液循环中MMP-2和MMP-9活性的影响。28只Wistar大鼠被随机分为四组（每组 = 7只）：年轻久坐组（YS）；年轻训练组（YT）、老年久坐组（OS）和老年训练组（OT）。爬楼梯抗阻训练每两天进行一次，每次攀爬进行8 - 12次动态动作。实验期结束后48小时对动物实施安乐死。通过酶谱法测量MMP-2和MMP-9活性。与OS、YS和YT组相比，OT组腓肠肌外侧头和趾长屈肌中的活性MMP-2活性更高（P≤0.001）。此外，与YS和YT组相比，OT组腓肠肌内侧头中的活性MMP-2活性更高（P≤0.001）。YS组比目鱼肌中的活性MMP-2活性低于YT、OS、OT组（P≤0.001）。关于血液中活性MMP-2/9活性，与YS和YT组相比，OT组的活性显著降低（P≤0.001）。总之，抗阻训练上调衰老肌肉中的MMP-2活性，同时下调血液循环中的MMP-2和MMP-9，表明它可能是维持细胞外基质重塑的有用工具。
