1. Biosynthesis of PGE2 from [14C]arachidonic acid has been found to be lower and PGF2α higher in the renal medulla of spontaneously hypertensive (SH) rats than in normal Wistar (NW) rats.
2. Biosynthesis of prostacyclin (PGF1α) from [14C]arachidonic acid was decreased in lungs, aorta and heart of SH rats.
3. Metabolism of [3H]PGF1α was decreased in renal cortex and lungs and PGE2 increased in SH rats in comparison with NW rats. Thus the lungs of SH rats let more PGF and less PGE enter the systemic circulation.
4. Emotional stress decreased the metabolism of [3H]PGF1α in lungs of SH and NW rats, the effect being less in SH rats.