Cardiac synthesis of prostaglandins from arachidonic acid in man

The bioformation of PGs in the human heart was studied in 7 male volunteers by constant rate infusion of 14C-labelled arachidonic acid (AA) into the aortic root and simultaneous blood sampling from the coronary sinus. After conventional extraction of lipids from the plasma samples, the various 14C-PGs formed were separated and quantified by means of thin layer chromatography and fractionated liquid scintillation spectrometry. The infused arachidonic acid was metabolized and well defined chromatographic peaks of 14C-PGs were obtained. Apart from a chromatographic peak corresponding to 14C-PG metabolites, 6-keto-PGF1 alpha constituted the main 14C-PG formed (23 +/- 8%) reflecting a considerable synthesis of prostacyclin in the heart. 14C-PGs of the D, E and F series were formed in roughly equal amounts (14--19%). In a 54-year-old subject, 6-keto-PGF1 alpha constituted a greater proportion of 14C-PGs (60%) than in the other subjects. This can reflect a general effect of ageing or it can indicate the presence of ischemic heart disease in this subject.