The influence of ultraviolet B irradiation on the excretion of the main urinary metabolite of prostaglandin F1 alpha and F2 alpha in psoriatic and normal subjects

Abstract

The influence of ultraviolet B (UVB) irradiation on the excretion of the main urinary metabolite of prostaglandin F1 alpha and F2 alpha (PGF-MUM) in 7 normal male volunteers and 7 male patients with stable psoriasis was examined. The excretion of PGF-MUM was increased during the first 24 hours after UVB irradiation of back skin and was generally reduced to near pre-irradiation levels during the next 24 hours after irradiation, in both normal and psoriatic subjects. Although pre-irradiation levels of PGF-MUM excretion in psoriatic patients were lower than those in normal subjects as previously reported, it was demonstrated that PGF-MUM excretion after UVB irradiation in psoriatic patients was fairly increased and amounted to near the mean pre-irradiation level in normal subjects. These results suggested not only a disorder in endogenous prostaglandin synthesis in psoriatic patients but a considerable capacity of psoriatic skin to synthesize prostaglandin after UVB irradiation.