Effects of atherosclerosis on the coronary microcirculation

W. M. Chilian, Kevin C Dellsperger, S. M. Layne, C. L. Eastham, M. A. Armstrong, M. L. Marcus, D. D. Heistad

Research output: Contribution to journalArticlepeer-review

102 Scopus citations


We tested the hypothesis that atherosclerosis potentiates coronary vasoconstriction to serotonin and ergonovine. Coronary microvascular pressures and diameters were measured in the beating left ventricle in normal and atherosclerotic cynomolgus monkeys. Pressures were measured in arteries (190-350 μm diam) that were distal to atherosclerotic lesions. Microvascular pressure and simultaneous measurements of aortic pressure and myocardial blood flow were used to calculate segmental vascular resistance (large artery resistance and microvascular resistance) during serotonin, phenylephrine, and ergonovine dosages. Aortic pressure was maintained constant during all interventions. Administration of phenylephrine (50 μg·kg-1·min-1 iv) produced a similar increase in microvascular resistance from base line (P < 0.05) in atherosclerotic and normal animals, 26 ± 5 and 14 ± 9 mmHg·min·g·ml-1, respectively. Serotonin (50 μg/min) did not influence coronary resistance in normal animals but produced a significant increase in both large artery (8 ± 3 mmHg·min·g·ml-1) and microvascular resistance (21 ± 6 mmHg·min·g·ml-1) in atherosclerotic animals (P < 0.05). A higher dose of serotonin (200 μg/min) produced a modest increase in large artery resistance from base line in normal animals (3 ± 1 mmHg·min·g·ml-1) and a greater increase in atherosclerotic animals (9 ± 4 mmHg·min·g·ml-1) (P < 0.05) vs. normals). Ergonovine (10 μg·kg-1·min-1 iv elevated microvascular resistance in both normal and atherosclerotic animals (P < 0.05) but increased large artery resistance only in atherosclerotic animals (10 ± 4 mmHg·min·g·ml-1) (P < 0.05). In summary, coronary vasoconstrictor responses to serotonin and ergonovine were potentiated by atherosclerosis. Because augmented constrictor responses to serotonin were observed in both the diseased arteries and the microcirculation of atherosclerotic animals, we speculate that the pathophysiological consequences of atherosclerosis extend into the microcirculation.

Original languageEnglish (US)
Pages (from-to)H529-H539
JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
Issue number2 27-2
StatePublished - 1990


  • coronary resistance
  • phenylephrine
  • serotonin
  • α-adrenoceptors

ASJC Scopus subject areas

  • Physiology
  • Cardiology and Cardiovascular Medicine
  • Physiology (medical)


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