Role of prostaglandin E-2 and leukotriene B-4 in skin reaction induced by transdermal application of propranolol

Dermal application of propranolol (PRL) induced formation of erythema and e dema, and pseudoeosinophil infiltration in epidermis and dermis at the appl ication site in guinea pigs. We investigated the production of prostaglandi n E-2 (PGE(2)) and leukotriene B-4 (LTB4) at the application site of PRL an d the role of these inflammatory chemical mediators in the occurrence of th e skin reactions. PGE(2) was found to be produced at the application site s lightly after the accumulation of PRL released from the adhesive bandage in the patch test, and the amount of PGE(2) increased continuously, with a pe ak value obtained at 24 h after application. The time-course changes resemb led those of Delta a* value, the index of erythema formation determined by colorimetric measurement, and edema formation. The production of PGE(2) by dermal application of PRL was suppressed by local pretreatment with dexamet hasone or indomethacin. However, no notable production of LTB4 was observed at the application site of PRL.