He G W, Angus J A, Rosenfeldt F L
Baker Medical Research Institute, Prahran, Victoria, Australia.
J Cardiovasc Pharmacol. 1988 Jul;12(1):12-22. doi: 10.1097/00005344-198807000-00003.
The internal mammary artery (IMA) and saphenous vein (SV) are used routinely in coronary artery (CA) bypass graft surgery. The IMA may develop spasm during surgery, and the SV often develops spasm during removal from the leg. We sought to determine the relative reactivity of the canine CA, IMA, and SV to potential vasoconstrictor substances and especially to determine which vasodilator agents were effective in these different blood vessels. All vessels were arranged as ring segments suspended at optimal stretch in organ baths. Glyceryl trinitrate (GTN) caused relaxation of the three vessels but was less sensitive, less potent (as determined by EC50 values), and had a reduced range of relaxation in the IMA. Papaverine was less sensitive in the IMA as compared with the CA and SV. Nifedipine, verapamil, and diltiazem were potent relaxing agents in all three vessels when precontracted by K+, but were less potent in vessels contracted by the thromboxane mimetic U46619 or phenylephrine, especially in the SV. These studies highlight the marked differences in the response of IMA and CA to constrictor and dilator agents and reinforce the notion that calcium antagonists of different chemical classes have widely differing activities in vascular tissue.
乳内动脉（IMA）和大隐静脉（SV）在冠状动脉（CA）旁路移植手术中经常被使用。IMA在手术过程中可能会发生痉挛，而SV在从腿部取出时经常会发生痉挛。我们试图确定犬类CA、IMA和SV对潜在血管收缩物质的相对反应性，特别是确定哪些血管扩张剂对这些不同的血管有效。所有血管均被制成环形节段，以最佳张力悬浮于器官浴槽中。硝酸甘油（GTN）可使这三种血管舒张，但敏感性较低、效力较弱（由半数有效浓度值确定），且在IMA中的舒张范围减小。与CA和SV相比，罂粟碱在IMA中的敏感性较低。硝苯地平、维拉帕米和地尔硫䓬在被钾离子预收缩的所有三种血管中均为强效舒张剂，但在被血栓素类似物U46619或去氧肾上腺素收缩的血管中效力较弱，尤其是在SV中。这些研究突出了IMA和CA对收缩剂和舒张剂反应的显著差异，并强化了不同化学类别的钙拮抗剂在血管组织中具有广泛不同活性的观点。
