Department of Biophysics and Human Physiology, Medical University of Warsaw.
Tohoku J Exp Med. 2013 Dec;231(4):321-9. doi: 10.1620/tjem.231.321.
Renalase is a newly discovered amine oxidase and may lower blood pressure by metabolizing catecholamines. We have hypothesized that exercise and training may regulate renalase expression to control blood pressure. In this study, we investigated changes in renalase expression after exercise and training in white and red portion of the gastrocnemius muscle, kidney, and serum in rats. Rats were either untrained or subjected to six weeks of endurance training, which predominantly recruits red fibers. Rats from each group were sacrificed before (n = 10), immediately after (n = 10), or three hours (n = 10) following exercise. Renalase mRNA and protein levels were measured by RT-PCR and ELISA, respectively. There were no significant changes in renalase expression after prolonged training or acute exercise in the serum or red muscle of rats. However, in white muscle, renalase mRNA and protein levels decreased after acute exercise in untrained rats, whereas, in trained rats, its protein level remained unchanged, despite a decrease in mRNA. Thus, exercise influenced renalase expression only in white muscle fibers that are not predominantly recruited during exercise. The reduction of renalase protein in white muscle suggests that renalase may contribute to blood redistribution between contracting and non-contracting fibers during exercise. In the kidney, renalase protein levels decreased after training, while mRNA levels increased. The reduction in renalase protein levels may contribute to functional kidney hypoperfusion, which has been observed after training. In conclusion, exercise differentially regulates renalase expression in skeletal muscle and kidney.
肾酶是一种新发现的胺氧化酶，可能通过代谢儿茶酚胺来降低血压。我们假设运动和训练可能会调节肾酶的表达来控制血压。在这项研究中，我们研究了运动和训练后大鼠腓肠肌红白部、肾脏和血清中肾酶表达的变化。大鼠分为未训练组或进行六周的耐力训练组，耐力训练主要募集红肌纤维。每组大鼠在运动前（n = 10）、运动后即刻（n = 10）或运动后 3 小时（n = 10）处死。通过 RT-PCR 和 ELISA 分别测量肾酶 mRNA 和蛋白水平。在血清或红肌中，长时间训练或急性运动后肾酶表达没有明显变化。然而，在白肌中，未训练大鼠急性运动后肾酶 mRNA 和蛋白水平降低，而训练大鼠尽管 mRNA 减少，但其蛋白水平保持不变。因此，运动仅影响非运动时主要募集的白肌纤维中的肾酶表达。白肌中肾酶蛋白的减少表明，肾酶可能有助于运动时收缩和非收缩纤维之间的血液再分配。在肾脏中，训练后肾酶蛋白水平降低，而 mRNA 水平升高。肾酶蛋白水平的降低可能导致功能性肾脏低灌注，这在训练后观察到。总之，运动对骨骼肌和肾脏中的肾酶表达有差异调节作用。
