Department of Physiology, Faculty of Medicine, Bursa Uludag University, 16059, Bursa, Turkey.
Peptides. 2022 Jan;147:170685. doi: 10.1016/j.peptides.2021.170685. Epub 2021 Nov 5.
Irisin, an exercise-induced myokine, has been shown to have a peripheral vasodilator effect. However, little is known about the mechanisms underlying its effects. In this study, it was aimed to investigate the vasoactive effects of irisin on rat thoracic aorta, and the hypothesis that voltage-gated potassium (K) channels, ATP-sensitive potassium (K) channels, small-conductance calcium-activated potassium (SK) channels, large-conductance calcium-activated potassium (BK) channels, intermediate-conductance calcium-activated potassium (IK) channels, inward rectifier potassium (K) channels, and two-pore domain potassium (K) channels may have roles in these effects. Isometric contraction-relaxation responses of isolated thoracic aorta rings were measured with an organ bath model. The steady contraction was induced with both 10 M phenylephrine and 45 mM KCl, and then the concentration-dependent responses of irisin (10-10 M) were examined. Irisin exerted the vasorelaxant effects in both endothelium-intact and -denuded aortic rings at concentrations of 10, 10, and 10 M (p < 0.001). Besides, K channel blocker 4-aminopyridine, K channel blocker glibenclamide, SK channel blocker apamin, BK channel blockers tetraethylammonium and iberiotoxin, IK channel blocker TRAM-34, and K channel blocker barium chloride incubations significantly inhibited the irisin-induced relaxation responses. However, incubation of K TASK-1 channel blocker anandamide did not cause a significant decrease in the relaxation responses of irisin. In conclusion, the first physiological findings were obtained regarding the functional relaxing effects of irisin in rat thoracic aorta. Furthermore, this study is the first to report that irisin-induced relaxation responses are associated with the activity of K, K, SK, BK, IK, and K channels.
鸢尾素是一种运动诱导的肌因子，已被证明具有外周血管舒张作用。然而，其作用机制知之甚少。本研究旨在探讨鸢尾素对大鼠胸主动脉的血管活性作用，并提出假设，即电压门控钾 (K) 通道、ATP 敏感性钾 (K) 通道、小电导钙激活钾 (SK) 通道、大电导钙激活钾 (BK) 通道、中间电导钙激活钾 (IK) 通道、内向整流钾 (K) 通道和双孔域钾 (K) 通道可能在这些作用中发挥作用。采用器官浴模型测量分离的胸主动脉环的等长收缩-舒张反应。用 10 μM 苯肾上腺素和 45 mM KCl 诱导稳定收缩，然后检测鸢尾素 (10-10 M) 的浓度依赖性反应。鸢尾素在有内皮和无内皮的主动脉环中均发挥舒张作用，浓度分别为 10、10 和 10 M（p<0.001）。此外，K 通道阻滞剂 4-氨基吡啶、K 通道阻滞剂格列本脲、SK 通道阻滞剂阿帕米、BK 通道阻滞剂四乙铵和iberiotoxin、IK 通道阻滞剂 TRAM-34 和 K 通道阻滞剂氯化钡孵育均显著抑制鸢尾素诱导的舒张反应。然而，K TASK-1 通道阻滞剂大麻素孵育并没有导致鸢尾素舒张反应的显著下降。总之，本研究首次获得了鸢尾素在大鼠胸主动脉中具有功能性舒张作用的生理发现。此外，本研究首次报道鸢尾素诱导的舒张反应与 K、K、SK、BK、IK 和 K 通道的活性有关。
