Angus J A, Cocks T M, Satoh K
Br J Pharmacol. 1986 Aug;88(4):767-77. doi: 10.1111/j.1476-5381.1986.tb16249.x.
Ring preparations from the carotid, coronary, renal, mesenteric and femoral arteries of the dog were precontracted with the thromboxane mimetic U46619, after ensuring that the resting conditions were comparable from the Laplace relationship. In the presence of prazosin (1 microM) and propranolol (3 microM), noradrenaline (NA) relaxed the arteries in the order coronary greater than carotid greater than femoral greater than renal = mesenteric. When maximum relaxation to nitroglycerin (10 microM) was taken to be 100% the maximum relaxation to noradrenaline in each artery was: coronary 70%; carotid 34%; femoral 19%; renal 7% and mesenteric 2%. In endothelium-intact arteries UK14304 mimicked the relaxation responses to NA and idazoxan shifted the curves to both agonists to the right, consistent with an alpha 2-adrenoceptor classification. Substance P relaxed the arteries in the same order as for NA but showed higher efficacy i.e.: coronary 100%; carotid 80%; femoral 71% renal 49%; and mesenteric 41%. Removal of the endothelium abolished the relaxation to NA. We conclude that endothelium-dependent relaxation to NA and substance P varies greatly across 5 large arteries of the dog. This may indicate that endothelium-derived relaxing factor (EDRF) release is site-dependent or that the efficacy of EDRF on smooth muscle varies; being greatest in the coronary and weakest in the renal and mesenteric arteries.
在确保根据拉普拉斯关系得出的静息状态具有可比性之后，用血栓素类似物U46619对犬的颈动脉、冠状动脉、肾动脉、肠系膜动脉和股动脉的环行标本进行预收缩。在存在哌唑嗪（1微摩尔）和普萘洛尔（3微摩尔）的情况下，去甲肾上腺素（NA）使各动脉舒张，其舒张顺序为：冠状动脉＞颈动脉＞股动脉＞肾动脉 = 肠系膜动脉。当将对硝酸甘油（10微摩尔）的最大舒张反应设定为100%时，各动脉对去甲肾上腺素的最大舒张反应分别为：冠状动脉70%；颈动脉34%；股动脉19%；肾动脉7%；肠系膜动脉2%。在完整内皮的动脉中，UK14304模拟了对NA的舒张反应，咪唑克生使两种激动剂的曲线均右移，这与α2 -肾上腺素能受体分类一致。P物质使动脉舒张的顺序与NA相同，但显示出更高的效能，即：冠状动脉100%；颈动脉80%；股动脉71%；肾动脉49%；肠系膜动脉41%。去除内皮后，对NA的舒张反应消失。我们得出结论，犬的5条大动脉对NA和P物质的内皮依赖性舒张反应差异很大。这可能表明内皮源性舒张因子（EDRF）的释放具有部位依赖性，或者EDRF对平滑肌的效能有所不同；在冠状动脉中最大，在肾动脉和肠系膜动脉中最弱。
