Amplification by phenylephrine and serotonin of coronary vasoconstriction induced by a high arterial blood oxygen tension

• Published in: Cardiovascular research 1994-09, Vol.28 (9), p.1326-1330
• Main Authors: Mouren, Stéphane, Vicaut, Eric, Charansonney, Olivier, Duvelleroy, Michel
• Format: Article
• Language: English
• Subjects: Animals; Biological and medical sciences; Cardiovascular system; coronary perfusion pressure; Coronary Vessels - drug effects; Coronary Vessels - physiopathology; Equipment and Supplies; high arterial oxygen tension; Hyperoxia - physiopathology; Investigative techniques of hemodynamics; Investigative techniques, diagnostic techniques (general aspects); Male; Medical sciences; Perfusion; phenylephrine; Phenylephrine - pharmacology; Rabbits; serotonin; Serotonin - pharmacology; Space life sciences; Stimulation, Chemical; Swine; Vasoconstriction - drug effects
• ISSN: 0008-6363; 1755-3245
• DOI: 10.1093/cvr/28.9.1326

Objective: The aim was to investigate the effect on the coronary network of the interaction between high arterial blood oxygen tension (Pao2) and stimulation by the α adrenergic agonist phenylephrine or by serotonin in an isolated, blood perfused rabbit heart preparation. Methods: Fresh pig erythrocytes in Krebs-Henseleit buffer were oxygenated to reach normal Pao2 [19.4(SEM 0.7) kPa] or high Pao2 [53.2(5.5) kPa]. Blood oxygen content was kept constant despite the higher Pao2, by slightly reducing the haemoglobin concentration from 9.3(0.2) to 8.8(0.2) g·100 ml−1 (p < 0.01). Coronary blood flow was kept constant throughout the study, so that the oxygen supply would not vary with the rise in Pao2. Increases in coronary resistance were therefore reflected by increased perfusion pressure. Results: Switching from normal to high Pao2 induced coronary vasoconstriction, reflected by enhanced perfusion pressure of +21(5)%. After pretreatment with the α adrenergic agonist phenyleprine, perfusion of a high Pao2 solution increased coronary resistance by +35(7)% (p