6-ketoprostaglandin-f1-alpha and Erythema

The buttock skin of clinically normal human subjects was subjected to approximately 2.5 minimal erythema doses of ultraviolet A irradiation. Deep red erythema developed during irradiation, faded slightly within the next few hours, increased to maximum intensity between 9-15 h, and decreased gradually thereafter although still persisting strongly at 48 h. Suction blister exudates were obtained at 0, 5, 9, 15, 24, and 48 h after irradiation as well as suction blister exudates from a contralateral control site and assayed for arachidonic acid, prostaglandins D2 and E2, and the prostacyclin breakdown product 6-oxo-prostaglandin F1 alpha by gas chromatography-mass spectrometry, and for histamine by radioenzyme assay. Increased concentrations of arachidonic acid and prostaglandins D2, E2, and 6-oxo-prostaglandin F1 alpha were found maximally between 5-9 h after irradiation, preceding the phase of maximal erythema. Elevations of histamine concentration occurred 9-15 h after irradiation, preceding and coinciding with the phase of maximal erythema. At 24 h, still at the height of the erythemal response, all values had returned to near control levels. Hence increased concentrations of arachidonic acid and its products from the cyclooxygenase pathway, and of histamine, accompany the early stages up to 24 h. A causal role in production of the erythema seems likely for these substances although other mediators are almost certainly involved.

Topics: 6-Ketoprostaglandin F1 alpha; Arachidonic Acids; Dinoprostone; Epoprostenol; Erythema; Female; Histamine; Humans; Male; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E; Skin; Skin Temperature; Ultraviolet Rays

The inside skin of the forearm of healthy volunteers was irradiated with an infrared (IR) lamp for 1 hr, resulting in the rapid appearance of an erythema and an elevation of skin surface temperature from 30 +/- 1 degree C to 38 +/- 2 degrees C within 5 min. The erythema and elevated skin surface temperature decayed within 10-30 min when the IR irradiation was stopped. Suction blisters were raised on nonirradiated skin and on irradiated skin both during irradiation and at various times after irradiation stopped. Elevated levels of free arachidonic acid, PGE2, PGD2, PGF2 alpha and 6-oxo-PGF1 alpha were found up to 24 h after irradiation. By 48 h the prostaglandin levels had returned to control values whereas the free arachidonic acid levels were still elevated at 72 h. The peak level of 6-oxo-PGF1 alpha appears between 0-6 h whereas for PGE2, D2, and F2 alpha it is between 6-16 h, suggesting a different cellular source for this prostaglandin.

Topics: 6-Ketoprostaglandin F1 alpha; Adolescent; Adult; Aged; Arachidonic Acids; Dinoprost; Dinoprostone; Erythema; Female; Forearm; Humans; Male; Middle Aged; Prostaglandin D2; Prostaglandins; Prostaglandins D; Prostaglandins E; Prostaglandins F; Skin; Skin Temperature; Ultraviolet Rays