Brum J M, Go V L, Sufan Q, Lane G, Reilly W, Bove A A
Regul Pept. 1986 Mar;14(1):41-55. doi: 10.1016/0167-0115(86)90204-1.
Substance P (SP), a vasoactive neuropeptide detected in animal and human hearts has been reported to increase coronary blood flow in animals. However, no data are available on SP effects on epicardial coronary arteries, the site of coronary disease. To determine the amount and distribution of SP and its action in the large coronary vessels, we studied two groups of dogs. One group was anesthetized for collecting three 1 cm segments of the circumflex coronary artery (CX) and left anterior descending artery (LAD) through a left thoracotomy. These segments represented proximal (I), middle (II), and distal (III) portions of the two arteries. Concentrations (ng/g) of SP-like immunoreactivity (SP-LI) were determined by radioimmunoassay. SP-LI was present in LAD (I: 1.17 +/- 0.20, II: 1.08 +/- 0.36, III: 1.14 +/- 0.25) and CX (I: 1.44 +/- 0.38, II: 1.51 +/- 0.47, III: 0.70 +/- 0.20). SP differences among segments of LAD and segments I and II of CX were not significant, but there was a significant difference between segment III of CX and the others. In the second group of closed chest anesthetized dogs, we examined the effects of intracoronary SP infusion before and during administration of serotonin (5HT). LAD and CX artery responses (% area change) to SP and to SP plus 5HT were examined using quantitative coronary angiography. Intracoronary 133Xe in saline provided coronary flow data. SP infusion produced significant vasodilation in segment II (15% area increase) and III (17%) during the highest dose (1 microgram/min). The three SP doses infused with 5HT (0.05 mg/min) did not produce vasodilation, although LAD segment III constriction from 5HT was abolished during the highest dose of SP infusion. The presence of SP, and its dilatory effect on the coronary arteries, suggests a role in maintaining vasodilator tone in the coronary arteries.
P物质（SP）是一种在动物和人类心脏中检测到的血管活性神经肽，据报道它能增加动物的冠状动脉血流量。然而，关于SP对冠状动脉疾病发生部位——心外膜冠状动脉的影响，目前尚无相关数据。为了确定SP在大冠状动脉中的含量、分布及其作用，我们研究了两组犬。一组犬麻醉后，通过左胸切口收集三段1厘米长的冠状动脉，即旋支冠状动脉（CX）和左前降支动脉（LAD）。这些节段分别代表两条动脉的近端（I）、中段（II）和远端（III）部分。采用放射免疫分析法测定SP样免疫反应性（SP-LI）的浓度（纳克/克）。LAD（I：1.17±0.20，II：1.08±0.36，III：1.14±0.25）和CX（I：1.44±0.38，II：1.51±0.47，III：0.70±0.20）中均存在SP-LI。LAD各节段以及CX的I和II节段之间的SP差异不显著，但CX的III节段与其他节段之间存在显著差异。在第二组闭胸麻醉犬中，我们研究了在给予5-羟色胺（5HT）之前和期间冠状动脉内注入SP的效果。使用定量冠状动脉造影术检查LAD和CX动脉对SP以及对SP加5HT的反应（面积变化百分比）。冠状动脉内注入生理盐水的133Xe可提供冠状动脉血流数据。在最高剂量（1微克/分钟）时，冠状动脉内注入SP可使II节段（面积增加15%）和III节段（面积增加17%）产生显著的血管舒张。尽管在最高剂量的SP注入期间，5HT引起的LAD III节段收缩被消除，但与5HT（0.05毫克/分钟）一起注入的三种SP剂量均未产生血管舒张作用。SP的存在及其对冠状动脉的舒张作用表明其在维持冠状动脉血管舒张张力方面发挥作用。
