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Pressure‐dependent vasoactive effects of histamine in the coronary circulation
Author(s) -
Merrill Gary F.,
Kang Young Hee,
Wei Hwu Meei,
Fisher Hans
Publication year - 1987
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.1.4.3653582
Subject(s) - vasoactive , histamine , cardiology , circulation (fluid dynamics) , medicine , blood pressure , mechanics , physics
Twenty‐one isolated, perfused, spontaneously rhythmic guinea pig hearts (Langendorff preparation) were used to investigate the effects of coronary perfusion pressure (CPP) on the coronary vasoactive response to a continuous infusion of histamine. Heart rate (HR), coronary perfusate flow (CPF), left ventricular pressure, dp/dt max , oxygen extraction, and myocardial oxygen consumption ( MV ˙O 2) were measured at constant CPP of 40 ( n = 9), 53 ( n = 6), and 65 cm H 2 O ( n = 6) in the absence and presence of continuous intracoronary infusion of histamine [0.9 ± 0.2 μg/(min · g)]. At 40 cm H 2 O histamine caused significant coronary vasodilation. At 65 cm H 2 O histamine caused significant coronary vasoconstriction. At an intermediate pressure of 53 cm H 2 O histamine had no effect on CPF. At all three pressures HR, left ventricular pressure, dp/dt max , and oxygen extraction increased significantly in response to histamine. MV ˙O 2was unchanged by histamine at 65 cm H 2 O (flow was reduced but extraction increased). MV ˙O 2, increased modestly but significantly at 53 cm H 2 O (12% increase; flow unchanged but extraction increased), and increased prominently at 40 cm H 2 O (50% increase; flow and extraction increased). We conclude that the coronary vascular effects of continuously infused histamine are dependent on the preexisting, steady‐state level of CPP in the isolated perfused guinea pig heart.— M errill , G. F.; K ang , Y. H.; W ei , H. M.; F isher , H. Pressure‐dependent vasoactive effects of histamine in the coronary circulation. FASEB J. 1: 308‐311; 1987.