Beta Adrenergic Stimulation of Endogenous Epidermal Cyclic AMP Formation

Abstract

We envision the epidermal chalone mechanism as an epinephrine-activated cascade of intra-epidermal molecular events whereby the feedback control of epidermal cell division is mediated via adenosine 3′,5′-monophosphate (cyclic AMP). Sutherland's first criterion of a cyclic AMP mediated event appears to have been satisfied in that isoproterenol (1 × 10^-6M) produced a threefold (<i>P</i>&lt; 0.001) rise in cyclic AMP level within three minutes in epidermal target tissue which was followed by inhibition of epidermal cell division. Since keratinocytes comprise approximately 95% of epidermal volume, we suggest that the majority of cyclic AMP measured was synthesized in keratinocytes.