ABSTRACT
Objective To investigate the influences of photochemotherapy with psoralen and ultraviolet A (PUVA) on skin photoaging and its possible mechanism. Methods HE stain, Verhoeff stain, electron microscopy, enzyme cytochemistry and immunocytochemistry were used to study influences of PUVA on the skin photoaging with characteristic biological markers in the non-lesion back skin of patients with psoriasis vulgaris. Results After treatment with PUVA, the degenerated collagen and elastic fibers were increased with derangement profile in dermis, and fibroblasts displayed growth suppression and morphological changes of cell senescence with a permanent switch of mitotic to stably postmitotic phenotypes, of group B and group A, the positive rates of SA-?-Gal were 13.6 % and 0.00 % and the positive rates of p16 protein were 81.8 % and 42.9 % respectively, there were significant differences between group B and group A(? 2=21.412, P