Effect of epidermal polyamine depletion on the accumulation of methylglyoxal bis(guanylhydrazone) in mouse skin.

A systemic or topical treatment of mice with alpha-difluoromethylornithine, and irreversible inhibitor of mammalian ornithine decarboxylase, produced a rapid depletion of epidermal putrescine and spermidine. When methylglyoxal bis(guanylhydrazone), another inhibitor of polyamine biosynthesis and a potent antiproliferative agent, was subsequently administered the epidermal concentration of the latter drug rose distinctly higher than without a prior difluoromethyl ornithine treatment. The combined use of these 2 antimetabolites of polyamines also profoundly depressed epidermal DNA synthesis, especially in UV-irradiated skin.

Reduction of increased polyamine levels in psoriatic lesions by retinoid and PUVA treatments.

Treatment with an oral aromatic retinoid (etretinate) and with PUVA significantly reduced the elevated levels of putrescine, spermidine and spermine in psoriatic lesions. Both treatments also significantly reduced the spermidine/spermine ratio, which is considered to be an indicator of proliferation activity. Although both regimens produced a roughly parallel reduction of epidermal polyamines the initial fall of putrescine was much more rapid in patients receiving retinoid.