Cyclic AMP and psoriasis once more.

Imbalanced cyclic nucleotides are implicated as an underlying pathogenetic mechanism in psoriasis, but conflicting data on the levels of cAMP in psoriatic tissue have been obtained by different laboratories. Using heat separation and a competitive protein binding cAMP assay, a noticeably decreased epidermal level of cAMP was detected in newly formed guttate lesions in 10 patients with psoriasis (involved: 4.32 +/- 1.06 pmol/mg dry weight mean +/- S.E.M.). uninvolved: 7.97 +/- 1.63 pmol/mg dry weight mean +/- S.E.M.). In proliferative rat skin, bidirectional alterations in cAMP levels are known to occur. On the basis of present observation, we assume that the conflicting data hitherto obtained in psoriatic tissue similarly may merely reflect the various levels of cAMP at different developmental stages.