RESUMO
BACKGROUND: The combination of psoralen and UVA (PUVA) as a model of photochemotherap, has been used in a wicle variety of cutaneous disorders such as psoriasis, vitiligo, mycosis fungoides and atopic dermatitis. The mechanism of PUVA of psoriasis is based on the fact. that PUVA causes photoconjugation of psoralens to DNA and a subsequent suppression of mitosis, DNA synthesis, and keratinocyte proliferation. Although PUVA apparently inhibits keratinocytie proliferation and is effective therefore in the treatment of psoriasis, PUVA increases pigmentations by stimulating melanocyte proliferation and melanin synthesis in vivo. OBJECTIVE: We tried to investigate the PUVA effects on the proliferation and different,iation in cultured human keratinoc tes and melanocytes. METHODS: We examined morphologic changes, and the number of the cultured human keratinocytes and melanoiytes and melanin contents in a control group and experimental group. (UVA group, 8-MOP group and PUVA group). i.e., UVA group was exposed to UVA at 60mJ, of. 8-MOP group was acJded at dose of 2 x 10 M to medium for 30 minutes. PUVA group was exposed to UVA at 60mJ, of after adding in 8 MOP at Zx 10 M for 30 minutes. RESULTS: 1. Morphologic changes of cultured human keratinocytes and melanocytes. There were no significent changes between the control group and the experimental groups in keratinocytes and melanocytes after 24, 48 and 72 hours culture. The number and length of meianocyte dendrites showecl no significant differences between the groups after 24, 48 and 72 hours culture(p>0.05). 2. Proliferation of cultured human keratinocytes and melanocytes 1) The number of keratinocytes in 8-MOP and PUVA groups decreased significantly more than in the control and LVA groups at 72nd hour after culture (p0.05). 3. Melanin contents in iultured human melanocytes The melanin contents increased significantly in the PUVA groups compared to that in the other groups at 72nd hour after culture (p<0.01). CONCLUSION: In culturel human keratinocytes, PUVA has no effect on the morphology and differentiation, hut inhibit proliferation. In cultured human melanocytes, PUVA has no effect on morphology and proliferation, but it increases the melanin contents.