Hashimoto M, Ishida Y, Naruse I, Paul R J
Department of Physiology and Biophysics, College of Medicine, University of Cincinnati, Ohio 45267-0676.
J Vasc Res. 1992 Mar-Apr;29(2):64-70. doi: 10.1159/000158934.
In the presence of potassium (K+), A23187 and substance P elicited endothelium-dependent relaxations of porcine coronary arteries. Isoproterenol or hypoxia elicited endothelium-independent relaxations. Rubbing the artery potentiated the contractile response to a low K+ concentration (15.4 mM). After intact arteries had been stored at 5 degrees C for 3 days, K(+)-induced maximal tension was not affected, but contractile responses to 15 mM K+ were potentiated with a decrease in ED50, suggesting that cold storage produces a supersensitivity to K+. Endothelium-dependent relaxations were abolished after 3 days of cold storage, while endothelium-independent relaxations were not inhibited. Cold storage of arteries with l-arginine (1 mM) for 3 days did not alter the relaxation responses to substance P and A23187, indicating that l-arginine does not prevent the loss of endothelium-dependent relaxation. Cold storage for 5 days inhibited the maximal tension to K+ and abolished the supersensitivity. Scanning electron micrographs showed that endothelial cells can be damaged by prolonged cold storage. The changes in tension response of the artery were correlated with the time course of endothelial cell loss resulting from cold storage.
在有钾离子（K+）存在的情况下，A23187和P物质可引起猪冠状动脉的内皮依赖性舒张。异丙肾上腺素或缺氧引起非内皮依赖性舒张。摩擦动脉可增强对低钾浓度（15.4 mM）的收缩反应。完整动脉在5℃下储存3天后，K+诱导的最大张力不受影响，但对15 mM K+的收缩反应增强，ED50降低，表明冷藏会产生对K+的超敏感性。冷藏3天后内皮依赖性舒张消失，而非内皮依赖性舒张未受抑制。用L-精氨酸（1 mM）将动脉冷藏3天并未改变对P物质和A23187的舒张反应，表明L-精氨酸不能防止内皮依赖性舒张的丧失。冷藏5天会抑制对K+的最大张力并消除超敏感性。扫描电子显微镜照片显示，长时间冷藏会损伤内皮细胞。动脉张力反应的变化与冷藏导致的内皮细胞丧失的时间进程相关。
