Epinephrine-induced cyclic AMP accumulation in the psoriatic epidermis

Abstract

Although there are many reports concerning different beta-adrenergic responsiveness in involved and uninvolved skin of psoriasis, previous experiments have been done mainly by using keratome-sliced skin, which contains unknown amounts of stratum corneum, dermis, skin appendages, etc. In order to determine the effect of epinephrine on the cyclic AMP level of ´pure´ epidermis in psoriasis, a microdissection technique was employed. Basal levels of cyclic AMP in the involved epidermis were slightly higher than in the uninvolved epidermis (involved 1.9 +/- 0.3 pmoles/mg dry weight; uninvolved 1.3 +/- 0.3 pmoles/mg d.w.). This difference was not statistically significant (p greater than 0.1). The response to epinephrine by the involved epidermis (8.4 +/- 1.0 pmoles/mg d.w.) was much lower than that in the uninvolved epidermis (23.3 +/- 4.3 pmoles/mg d.w.). The difference was statistically highly significant (p less than 0.005). Our data show that psoriatic involved epidermis per se had a reduced beta-adrenergic responsiveness, which might be significantly involved in the pathophysiology of psoriasis.