Smitherman T C, Popma J J, Said S I, Krejs G J, Dehmer G J
Medical Services, Veterans Administration Medical Center, Dallas 75216.
Am J Physiol. 1989 Oct;257(4 Pt 2):H1254-62. doi: 10.1152/ajpheart.1989.257.4.H1254.
Vasoactive intestinal polypeptide (VIP), a probable neurotransmitter, is present in the hearts of experimental animals and is a coronary vasodilator in dogs. We evaluated the coronary hemodynamic effects of intravenously infused VIP in 11 men at two rates that modestly raised circulating VIP concentrations. The decreases in coronary and systemic vascular resistances during the second infusion, 33 and 31%, respectively, were slightly but insignificantly greater than the 24% decrease in pulmonary vascular resistance. Coronary sinus levels of 6-keto-prostaglandin F1 alpha were not elevated during the infusions, and cyclooxygenase inhibition did not significantly blunt coronary vasodilation. However, myocardial oxygen uptake rose significantly during both infusions. To test for a direct coronary vasodilator effect, we infused VIP into the left coronary artery of four other men at four levels. The maximum decline in coronary vascular resistance was 46% and was not associated with an increase in myocardial oxygen uptake. We conclude that 1) intravenous administration of low to intermediate doses of VIP in humans is associated with substantial coronary vasodilation, 2) the coronary bed appears to be at least as responsive as other vascular beds, 3) the coronary vasodilation is due to both direct and indirect effects, and 4) the coronary vasodilation does not appear to be mediated by prostaglandins.
血管活性肠肽（VIP）可能是一种神经递质，存在于实验动物的心脏中，是犬类的冠状动脉扩张剂。我们以两种适度提高循环中VIP浓度的速率，评估了静脉输注VIP对11名男性冠状动脉血流动力学的影响。第二次输注期间冠状动脉和全身血管阻力分别下降了33%和31%，略高于肺血管阻力下降的24%，但差异无统计学意义。输注期间冠状窦6-酮-前列腺素F1α水平未升高，环氧化酶抑制也未显著减弱冠状动脉扩张。然而，两次输注期间心肌氧摄取均显著增加。为了测试直接冠状动脉扩张作用，我们在另外四名男性的左冠状动脉中以四个水平输注VIP。冠状动脉血管阻力的最大下降为46%，且与心肌氧摄取增加无关。我们得出以下结论：1）在人类中静脉注射低至中等剂量的VIP与显著的冠状动脉扩张有关；2）冠状动脉床似乎至少与其他血管床一样敏感；3）冠状动脉扩张是直接和间接作用共同导致的；4）冠状动脉扩张似乎不是由前列腺素介导的。
