Influence of prostacyclin on coronary thrombosis and myocardial ischemia in conscious canine experiments

The effects of intraventricular infusion of prostacyclin (PGI2; 50, 100 ng/kg/min) on hemodynamics, the ECG, coronary thrombosis and myocardial ischemia were studied in chronically equipped, resting conscious dogs and compared to those of intracardiac administration of Tris-HCl as vehicle. Coronary...

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Bibliographic Details
Published inArchives internationales de pharmacodynamie et de thérapie Vol. 278; no. 1; p. 114
Main Authors Fiedler, V B, Mardin, M
Format Journal Article
LanguageEnglish
Published Belgium 01.11.1985
Subjects
Animals
Blood Pressure - drug effects
Coronary Circulation - drug effects
Coronary Disease - physiopathology
Dogs
Electric Stimulation
Electrocardiography
Epoprostenol - pharmacology
Female
Heart Rate - drug effects
Hemodynamics - drug effects
Male
Time Factors
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Summary:The effects of intraventricular infusion of prostacyclin (PGI2; 50, 100 ng/kg/min) on hemodynamics, the ECG, coronary thrombosis and myocardial ischemia were studied in chronically equipped, resting conscious dogs and compared to those of intracardiac administration of Tris-HCl as vehicle. Coronary thrombosis was induced by electrical stimulation of an artery over an implanted wire for 6 hr. PGI2 infusion at 100 ng/kg/min decreased blood pressure by 24 +/- 3% (p less than 0.01) for 5 hr, increased heart rate at 1 hr by 28 +/- 4% (p less than 0.05) followed by a decrement, and elevated cardiac output by 41 +/- 3% (p less than 0.05). Filling pressure and dP/dtmax did not change. Treatment with PGI2 prevented ischemic S-T segment alterations in the ECG and arrhythmias observed in controls. The prostanoid infusion reduced coronary thrombus weight from 64 +/- 7.8 mg (mean +/- S.D.) in controls to 10.7 +/- 6.3 mg and 5.2 +/- 7.1 mg (both p less than 0.001) after 50 and 100 ng/kg/min, respectively. It also reduced myocardial ischemia following occlusive coronary thrombosis from 48 +/- 12% of the left ventricle in controls to 8.8 +/- 8.7% (p less than 0.01) and 2.4 +/- 5.2% (p less than 0.001) in the hearts treated with 50 or 100 ng/kg/min PGI2. The results suggest that PGI2 infusion exerts beneficial effects on heart performance by long-lasting blood pressure reduction and elevation of cardiac output caused by dilation of arterial vessels. PGI2 infusion prevents occlusive coronary artery thrombosis in response to intimal damage by anti-thrombotic properties and vasodilation of coronary arteries. This protects the heart from ischemia observed in controls.
ISSN:0003-9780