The relationship between development of ultraviolet erythema and release of prostaglandins in guinea pig skin.

Ultraviolet erythema in the guinea pid has been in use for many years as a model for assessing the anti-inflammatory potency of non-steroidal anti-inflammatory agents, the degree of erythema usually being estimated about 2 h after u.v. exposure. Using a suction blister technique for obtaining tissue fluid from erythemic and normal skin of the guinea pig we have shown that prostaglandin output in ultraviolet-irradiated skin increases rapidly during the first 2 h after irradiation, at which time the erythema reaches near-maximal development. Flurbiprofen, a potent non-steroidal anti-inflammatory agent, almost totally prevents the appearance of prostaglandins in the blister fluid and significantly reduces the degree of erythema in the skin during this early period. However, in flurbiprofen-treated animals, although prostaglandin synthesis is also suppressed at 4 to 5 h after exposure and is still partially suppressed at 17 h, a well developed erythema nevertheless appears by 4 h. This indicates the appearance of one or more non-prostaglandin mediators in the later stages of the reaction.