Watanabe Nozomi, Akasaka Takashi, Fujimoto Katsukuni, Kajita Tatsuya, Shigeto Fumiyuki, Neishi Yoji, Ogasawara Yasuo, Yoshida Kiyoshi
Departments of Cardiology, Kawasaki Medical School, Matsushima, Kurashiki, Japan.
Circ J. 2004 Dec;68(12):1210-4. doi: 10.1253/circj.68.1210.
Previous experimental and clinical studies have reported that nicorandil, an adenosine triphosphate (ATP)-sensitive K+ channel opener, exerts a beneficial effect on microvascular function and clinical outcome after myocardial ischemia. The present study assessed whether intravenous administration of nicorandil affects the 3-dimensional (3-D) architectural characteristics of capillaries and their volume after early myocardial reperfusion.
Using the hearts of open-chest anesthetized rats, the left anterior descending artery was occluded for 7 min followed by reperfusion. Nicorandil or saline was infused intravenously during occlusion and reperfusion. The entire coronary microvasculature was filled with contrast medium after the hearts were arrested. Capillaries were observed 3-dimensionally by confocal laser scanning microscopy in both the control area and reperfused area of all samples. The capillary volume fraction was computed from the 3-D images. The reperfused area in both the nicorandil and saline groups showed characteristic architectural changes of the capillaries. Capillary volume fraction in the reperfused area was significantly reduced in saline group, compared with nicorandil group [12.7+/-7.2% vs 18.1 +/-5.3% (p<0.01)].
Intravenous nicorandil administration has a beneficial effect on capillary damage after reperfusion.
既往实验和临床研究报道，三磷酸腺苷（ATP）敏感性钾通道开放剂尼可地尔对心肌缺血后的微血管功能和临床结局具有有益作用。本研究评估了静脉注射尼可地尔是否会影响早期心肌再灌注后毛细血管的三维（3-D）结构特征及其容积。
使用开胸麻醉大鼠的心脏，将左前降支动脉闭塞7分钟后再灌注。在闭塞和再灌注期间静脉输注尼可地尔或生理盐水。心脏停搏后，整个冠状动脉微血管充满造影剂。通过共聚焦激光扫描显微镜对所有样本的对照区域和再灌注区域的毛细血管进行三维观察。根据三维图像计算毛细血管容积分数。尼可地尔组和生理盐水组的再灌注区域均显示出毛细血管的特征性结构变化。与尼可地尔组相比，生理盐水组再灌注区域的毛细血管容积分数显著降低[12.7±7.2% 对 18.1±5.3%（p<0.01）]。
静脉注射尼可地尔对再灌注后的毛细血管损伤具有有益作用。
