Nagata Y, Araki H, Tomoike H, Nakamura M
Basic Res Cardiol. 1985 Mar-Apr;80(2):210-7. doi: 10.1007/BF01910469.
Outer diameter of the isolated pig coronary artery was measured under isotonic conditions using a sonomicrometer, and tension development of a ring preparation was assessed isometrically by a strain gauge transducer. Potassium chloride (KCl), acetylcholine (ACh) and 5-hydroxytryptamine dose-dependently reduced the coronary outer diameter. There was a direct linear relation between the reduction of diameter and tension development by these agents (r = 0.91, n = 15, p less than 0.001). KCl was one of the most potent vasoconstrictors tested and reduced the outer diameter by 35 +/- 1% (n = 15, mean +/- SEM) at 120 mM. ACh produced a transient increase in isometric tension and the reduction of the coronary diameter by ACh was smaller than that seen with KCl, even with a dose which produced the similar peak level of isometric tension by KCl and ACh. It is concluded that changes in the coronary diameter do closely correlate with those in tension development, however, the reduction of coronary diameter after exposure to vasoconstrictive agents is less in phasic than tonic contraction. The latter evidence suggests the importance of both the strength and duration of active vasoconstriction in eliciting coronary spasm.
使用超声测量仪在等张条件下测量分离的猪冠状动脉外径，并用应变片传感器等长评估血管环标本的张力变化。氯化钾（KCl）、乙酰胆碱（ACh）和5-羟色胺均呈剂量依赖性地减小冠状动脉外径。这些药物引起的管径减小与张力变化之间存在直接线性关系（r = 0.91，n = 15，p < 0.001）。KCl是所测试的最有效的血管收缩剂之一，在120 mM时可使外径减小35±1%（n = 15，平均值±标准误）。ACh使等长张力短暂增加，且ACh引起的冠状动脉管径减小幅度小于KCl，即使给予能产生与KCl相似等长张力峰值水平的剂量时也是如此。结论是，冠状动脉管径变化与张力变化密切相关，然而，暴露于血管收缩剂后冠状动脉管径的减小在相性收缩中比在紧张性收缩中更小。后一证据表明，主动血管收缩的强度和持续时间在引发冠状动脉痉挛中均很重要。
