[Prostaglandin biosynthesis in psoriatic epidermis (author's transl)]

The biosynthesis of prostaglandins E2 (PGE2) and F2 alpha (PGF2) from exogenous arachidonic acid (AA) was investigated in 12 involved and uninvolved psoriatic epidermis and in 6 normal epidermis. PGE2 and PGF2 were determined by radio-immuno-assay after addition of 25 microgram of AA and 1 hour incubation. The biosynthesis of PGE2 and PGF2 alpha was higher in psoriatic epidermis than in control epidermis but lower in involved than in uninvolved epidermis. The ratio PGE2/PGF2 alpha is decreased in involved epidermis when compared with uninvolved epidermis and with controls. These quantitative and qualitative disturbances of the PG metabolism in psoriatic epidermis might play an important role in the pathogenesis of the disease. They could be responsible for abnormal keratinocyte differentiation and proliferation, lipid membrane abnormalities and abnormal immune response of psoriatic patients.