To investigate prostaglandin biosynthesis by the heart, 21 patients undergoing cardiac catheterization and coronary angiography for congenital or acquired heart diseases other than coronary artery disease were investigated. Prostacyclin (as 6-keto-PGF1α), PGE2, PGF2α and TxA2 (as TxB2) were measured by specific radioimmunoassay in blood from coronary sinus, aorta, and a peripheral vein under resting conditions and following cold pressor test (CPT). PGF2α was always found undetectable. In resting conditions, no significant differences in plasma 6-keto-PGF1α, PGE2, or TxB2 concentrations were found among coronary sinus, aorta, and peripheral venous blood and no transcardiac gradient existed (mean: +0.4 ± 1.2 pg/ml for 6-keto-PGF1α, + 0.1 ± 0.6 pg/ml for PGE2, and -0.4 ± 9.9 pg/ml for TxB2). CPT was able to induce a significant increase in 6-keto-PGF1α and PGE2 concentration in blood from the different sampling sites and a significant transcardiac gradient was found following CPT (+11.6 ± 7.4 pg/ml for 6-keto-PGF1α (p <0.01) and +5.2 ± 3.6 pg/ml for PGE2 (p <0.001). TxB2 levels significantly increased in peripheral venous blood (from 18.3 ± 6.2 to 29.2 ± 20.3 pg/ml, p <0.05), but they did not increase either in coronary sinus (from 21.9 ± 9.7 to 22.9 ± 9.8 pg/ml) or in aorta (from 22.3 ± 4.7 to 19.1 ± 6.5 pg/ml). Present results indicate that a cardiocoronary prostacyclin and PGE2 synthesis is inappreclable under resting conditions but it becomes remarkable following sympathetic stimulation. On the contrary, no TxA2 cardiocoronary biosynthesis seems to occur in patients free from coronary artery disease.
ASJC Scopus subject areas
- Cardiology and Cardiovascular Medicine