[Effects of verapamil preconditioning on cardiac function in vitro and intracellular free Ca2+ and L-type calcium current in rat cardiomyocytes post ischemia-reperfusion injury].

作者：Wei Yu, Jingjing Wang, Wen-Yun Gan, Guosheng Lin, Cong-Xin Huang · 发表于：PubMed · 年份：2010 · 被引用次数：11 · 研究领域：Medicine、Internal medicine、Cardiology、Anesthesia、Chemistry、Biochemistry

OBJECTIVE: To investigate the influences of verapamil preconditioning on cardiac function in vitro and intracellular free Ca2+ and L-type calcium current (I(Ca-L)) in rat cardiomyocytes post ischemia-reperfusion (I/R) injury. METHODS: The isolated rat hearts in control group (37 degrees C Tyrode solution perfusion for 30 min, n = 6), I/R group (no flow for 30 min followed 30 min reperfusion with 37 degrees C Tyrode solution, n = 7) and verapamil preconditioning group [37 degrees C Tyrode solution perfusion for 10 min, adding verapamil (20 micromol/L) to Tyrode solution and perfusion for another 30 min, followed then by 30 min no flow and 30 min reperfusion, n = 7] using Langendorff perfusion system. The fluorescence intensity of intracellular Ca2+ was detected with Fluo-3/AM loading by the laser scanning confocal microscope. The I(Ca-L) was recorded via whole-cell patch clamp technique in enzymatically dissociated single rat ventricular myocytes. RESULTS: As expected, arrhythmias and cardiac dysfunction were shown post I/R injury. The fluorescence intensities of intracellular free Ca2+ in cardiomyocytes were significantly increased compared with control group (P < 0.01). By voltage clamp protocol, peak current densities of I(Ca-L) was significantly reduced and I-V curve significantly elevated. Post I/R injury compared with control group (P < 0.01) which could be reversed by Verapamil preconditioning. Verapamil preconditioning also significantly improved diastolic and systolic...