Kalsner S
Prostaglandins Med. 1978 Sep;1(3):231-9. doi: 10.1016/0161-4630(78)90109-x.
Strips of beef coronary branch arteries, maintained in vitro, respond to decreased PO2 in the bathing medium with relaxations which are much attenuated by pretreatment with indomethacin or aspirin. It was determined that these hypoxia-induced relaxations are sustained until strips are returned to an environment of high PO2 and that the mechanism involved does not fatigue readily with repetitive exposure to hypoxic stress (53 mm Hg). It was also established that the reduced relaxations observed in the presence of inhibitors of prostaglandin synthesis were not enlarged with time by the development of an alternate process of relaxation independent of prostaglandins. Other experiments showed that when prostaglandin intervention is blocked with inhibitors the strips maintain a given level of tone to potassium chloride under a PO2 of 53 mm Hg, and do so without significant impairment over an observation period of one hour. Similarly, complete concentration-response curves to potassium did not differ under high (515 mm Hg) or low (53 mm Hg) PO2. This confirms that hypoxia-induced relaxation in beef coronary artery strips is a specific process, apparently mediated by a prostaglandin, rather than any consequence of the failure of the energetics of contraction.
在体外保存的牛冠状动脉分支条带，对浴液中PO2降低产生舒张反应，而吲哚美辛或阿司匹林预处理可显著减弱这种舒张反应。已确定这些缺氧诱导的舒张反应会持续到条带恢复到高PO2环境，且所涉及的机制在反复暴露于低氧应激（53 mmHg）时不易疲劳。还证实，在存在前列腺素合成抑制剂的情况下观察到的舒张反应减弱，不会因独立于前列腺素的另一种舒张过程的发展而随时间扩大。其他实验表明，当用抑制剂阻断前列腺素干预时，条带在53 mmHg的PO2下对氯化钾保持给定的张力水平，并且在一小时的观察期内不会受到明显损害。同样，在高（515 mmHg）或低（53 mmHg）PO2下，对钾的完整浓度-反应曲线没有差异。这证实了牛冠状动脉条带中缺氧诱导的舒张是一个特定过程，显然由前列腺素介导，而不是收缩能量学失败的任何结果。
