Selective hypercontraction caused by ergonovine in the canine coronary artery under conditions of induced atherosclerosis.
Selective hypercontraction caused by ergonovine in the canine coronary artery under conditions of induced atherosclerosis.
复制标题
在诱发动脉粥样硬化的条件下，麦角新碱引起犬冠状动脉选择性过度收缩。
作者：
Y. Kawachi;H. Tomoike;Y. Maruoka;Y. Kikuchi;H. Araki;Y. Ishii;K. Tanaka;M. Nakamura
通过动脉造影（原位）和机械图（体外）方法，研究了局部冠状动脉对麦角新碱的过度收缩反应与内皮剥脱和高胆固醇饮食后诱导的血管变化之间的关系。在15只杂种犬中，通过冠状动脉导管重复两次选择性冠状动脉左回旋支（LCX）或左前降支（LAD）内皮剥脱，间隔1个月。此后给予高胆固醇饮食（20 g/天）3个月（n = 15）和6个月（n = 8）。尽管在内皮剥脱之前或之后即刻，LAD和LCX之间的冠状动脉血管收缩程度没有差异，但在长期阶段（1至6个月），动脉造影显示麦角新碱静脉给药后，冠状动脉收缩沿着剥脱部分显著增加。在体内研究结束时，裸露和对侧完整冠状动脉条的等长张力在麦角新碱，5-羟色胺，或苯丙氨酸的器官浴的累积添加过程中进行测量;激动剂的反应标准化的35 mM KCl的反应。虽然苯乙哌啶（10（-9）M至10（-5）M）的浓度-反应关系在完整和裸露动脉之间没有显著差异，裸露部分对累积加入麦角新碱（10（-10）M）或5-羟色胺（10（-9）M至10（-5）M）的反应显示出明显降低的阈值浓度，沿着出现明显降低的负对数（pD2）产生50%最大效果的剂量。在累积添加麦角新碱的过程中，裸露部分的张力也比对侧冠状动脉中的张力增强，但在应用苯丙氨酸时没有。因此，动脉造影记录的收缩增强可能来自局部对麦角新碱的超敏反应。显微镜下，内皮剥脱和长期高胆固醇饮食导致局部内膜增厚伴纤维增生，但几乎没有脂质沉积。因此，动脉粥样硬化动脉中的平滑肌可能对特定激动剂过敏，例如犬制剂中的麦角新碱和5-羟色胺。这些结果表明，麦角新碱诱导的冠状动脉痉挛与血管壁中存在动脉粥样硬化变化有关。
The relationship between the hypercontractile response of the regional coronary artery to ergonovine and induced vascular change after endothelial denudation and a high-cholesterol diet was examined in dogs by arteriographic (in situ) and mechanographic (in vitro) methods. In 15 mongrel dogs, selective endothelial denudation of either the left circumflex coronary artery (LCX) or left anterior descending coronary artery (LAD) was repeated twice 1 month apart by means of coronary arterial catheterization. A high-cholesterol diet (20 g/day) was given thereafter for 3 (n = 15) and 6 (n = 8) months. Although there was no difference in the extent of coronary vasoconstriction between the LAD and LCX before or immediately after endothelial denudation, after intravenous administration of ergonovine a significant augmentation of coronary constriction along the denuded portion was noted arteriographically in the long-term phase (1 to 6 months). At the end of the study in vivo, isometric tension of the strips of the denuded and contralateral intact coronary arteries was measured during the cumulative addition of ergonovine, serotonin, or phenylephrine to the organ bath; agonist responses were standardized by the response to 35 mM KCl. Although the concentration-response relations for phenylephrine (10(-9) M to 10(-5) M) were not significantly different between intact and denuded arteries, responses of the denuded portion to cumulative addition of ergonovine (10(-10) M) or serotonin 10(-9) M to 10(-5) M) exhibited markedly depressed threshold concentrations along with a significantly lowered negative logarithm (pD2) of the dose producing 50% of the maximum effect. The tension developed in the denuded portion was also enhanced over that noted in the contralateral coronary artery during the cumulative addition of ergonovine but not during application of phenylephrine. Thus enhanced constriction documented arteriographically may be derived from the localized hypersensitivity to ergonovine. Microscopically, the endothelial denudation and a long-term high-cholesterol diet resulted in a regional intimal thickening with fibrous proliferation but little lipid deposition. Therefore smooth muscle in atherosclerotic arteries may be hypersensitive to specific agonists such as ergonovine and serotonin in a canine preparation. These results suggest that coronary spasm induced by ergonovine in humans is relevant to the presence of atherosclerotic changes in the vascular wall.