Biosynthesis of Prostaglandins from Arachidonic Acid in Guinea Pig Lung

The prostaglandins constitute a class of physiologically active compounds with a widespread occurrence in animal tissues (see References 2 and 3). Previous studies have led to the determination of their structures (4-S), and more recent investigations have shown that they can be formed enzymatically from the essential fatty acids (7,8). It was thus shown that in homogenates of vesicular glands from sheep, prostaglandin El (PGEr)’ is formed from 8,11,14-eicosatrienoic acid (9, lo), PGEz from 5,8,11,14-eicosatetraenoic acid (7, S), and PGEa from 5,8,11, 14,17-eicosapentaenoic acid (10). However, no PGF-compounds were detected. The experiments reported here, show that the biosynthesis of prostaglandins is not restricted to the vesicular gland, but it can also take place in homogenates of guinea pig lung. In this system, both PGF& and PGEz are formed from arachidonic acid.