PUVA increases ornithine decarboxylase gene expression in mouse skin.

The influence of topical PUVA on the activity of ornithine decarboxylase (ODC) and its gene expression was investigated in the skin of hairless mouse. After 1 h of application of 0.3% 8-methoxypsoralen, irradiation of 3 J/cm2 of ultraviolet A (UV-A) was administered. The ODC activity markedly increased and peaked at 24 h following UV-A irradiation. The ODC mRNA level, analyzed in dot-blot analysis, elevated to about 5 times that of control at 24 h after treatment. These results show that the PUVA-induced ODC activity is due in part to an increase in ODC gene expression.