- Title
- Modulation of baroreflex gain regulating coronary vasodilator responses by the central μ-opioid receptor agonist fentanyl
- Creator
- Moore, P. G.; Gazibarich, G. J.; White, Saxon William; Porges, W. L.
- Relation
- Blood Vessels Vol. 23, Issue 2
- Publisher Link
- http://dx.doi.org/10.1159/000158626
- Publisher
- S. Karger AG
- Resource Type
- journal article
- Date
- 1986
- Description
- In man and rabbit, anesthetic doses of the μ-opioid receptor agonist fentanyl cause systemic vasoconstriction. In unsedated dogs, intravenous infusion of fentanyl at 0.55 μg·kg⁻¹·min⁻¹ causes initial mild coronary vasodilatation but later vasoconstriction. Possible differential effects on baroreflex coronary vasodilator gain (ratio of percent change in circumflex conductance (CC) to aortic pressure induced by thoracic aorta balloon inflation) were studied in unsedated dogs in heart block (paced ventricles: Doppler probe on circumflex artery) during intravenous fentanyl infusion rates of 0.14, 0.28, 0.55 and 1.10 μg·kg⁻¹·min⁻¹. Fifteen minutes of fentanyl caused a rise in resting CC at the two lowest infusion rates, but a dose-dependent fall in CC and rise in aortic pressure at higher infusion rates. Gain of the vasodilator baroreflex increased at the two lowest infusion rates, but fell below pre-infusion gain at the highest infusion rates, suggesting that a physiological rise in μ-opioid receptor activity in the central nervous system may enhance baroreflex augmentation of CC in response to sudden rises in cardiac afterload. The effect is offset by coronary vasoconstriction induced during anesthetic doses.
- Subject
- vasodilatation; μ-opioid; fentanyl
- Identifier
- http://hdl.handle.net/1959.13/939338
- Identifier
- uon:12783
- Identifier
- ISSN:0303-6847
- Language
- eng
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