The effects of photosensitizers and ultraviolet irradiation on the biosynthesis and metabolism of prostaglandins

Abstract

Prostaglandin biosynthesis from arachidonic acid by skin microsomal fraction preparation was enhanced by UV∼irradiation at wavelengths of 254 and 360 nm. In the presence of S-methoxy psoralen (8 MOP) and coal tar, prostaglandin biosynthesis was further enhanced approximately 2-fold by UV-irradiation at 254 nm. Stimulation was less by UV-irradiation at 360 nm. 8-MOP enhanced the conversion of PGE, into PGF_2α by PGE₂-9-ketoreductase prepared from skin high speed supernatant fractions. UV-irradiation at 254 nm and 360 nm with or without the photosensitizers had no effect on the activity of the PGE₂-9-ketoreductase. These data therefore indicate that the action of UV-irradiation, 8-methoxy psoralen and coal tar on the skin may in part be due to their regulation of the biosynthesis and metabohsm of prosta-glandins in this tissue.