Sakaino N, Araki H, Nishi K, Kimura T, Yasue H
Department of Pharmacology, Kumamoto University Medical School, Japan.
Cardiovasc Res. 1988 Aug;22(8):555-61. doi: 10.1093/cvr/22.8.555.
Constriction of epicardial coronary arteries induces severe flow reduction causing myocardial ischaemia in patients with vasospastic angina. Whether such constriction is inherent in coronary arteries in general was determined by perfusing isolated epicardial coronary segments of humans and pigs at a constant perfusion pressure. Mean flow reduction after perfusion with potassium chloride (60 mmol.litre-1), acetylcholine (10(-9)-10(-5) mol.litre-1), and histamine (10(-8)-10(-4) mol.litre-1) was not different between humans and pigs. Prostaglandin F2 alpha (PGF2 alpha; 3 X 10(-6) mol.litre-1) decreased the flow more substantially in humans (by 74(9)%) than in pigs (by 6(1)%) (p less than 0.01). A pronounced flow reduction to 0 ml.min-1 was observed in eight of 17 human coronary arteries after potassium chloride, histamine, or PGF2 alpha perfusion but in none of the pigs. Histological examination of the coronary arteries showed no atherosclerotic lesions in the pigs but various lesions in humans, ranging from intimal thickening to 96% luminal stenosis in cross sectional area. Flow reduction after PGF2 alpha was significantly greater in human coronary arteries with stenoses greater than 50% (94(4)%) than in those with stenoses less than 25% (55(14)%) (p less than 0.05). Complete cessation of flow was observed more often in the stenotic arteries (greater than 50% stenosis) than in others (p less than 0.05). A substantial reduction in flow, which may cause myocardial ischaemia in vivo, was not seen in normal pig coronary arteries even after strong vasoconstrictor stimuli but was present in human coronary arteries with atherosclerosis.
心外膜冠状动脉收缩会导致严重的血流减少，从而引起变异性心绞痛患者的心肌缺血。通过在恒定灌注压力下灌注人和猪的离体心外膜冠状动脉节段，来确定这种收缩是否普遍存在于冠状动脉中。用氯化钾（60 mmol·L⁻¹）、乙酰胆碱（10⁻⁹ - 10⁻⁵ mol·L⁻¹）和组胺（10⁻⁸ - 10⁻⁴ mol·L⁻¹）灌注后，人和猪的平均血流减少情况并无差异。前列腺素F2α（PGF2α；3×10⁻⁶ mol·L⁻¹）使人类冠状动脉血流减少的幅度（74(9)%）比猪（6(1)%）更大（p<0.01）。在17条人类冠状动脉中，有8条在灌注氯化钾、组胺或PGF2α后出现明显的血流减少至0 ml·min⁻¹，但猪的冠状动脉中未出现这种情况。冠状动脉的组织学检查显示，猪的冠状动脉无动脉粥样硬化病变，而人类的冠状动脉有各种病变，从内膜增厚到横截面积管腔狭窄96%不等。PGF2α灌注后，狭窄大于50%的人类冠状动脉血流减少幅度（94(4)%）显著大于狭窄小于25%的冠状动脉（55(14)%）（p<0.05）。狭窄动脉（狭窄大于50%）比其他动脉更常出现血流完全停止的情况（p<0.05）。即使在强烈的血管收缩刺激后，正常猪冠状动脉中也未出现可能导致体内心肌缺血的明显血流减少，但在有动脉粥样硬化的人类冠状动脉中则存在这种情况。
