EFFECTS OF 4-TERTIARY BUTYL CATECHOL ON MELANOCYTES OF HAIRLESS MICE

[摘要] Depigmentary effects of [the industrial antioxidant] 4-tert-butyl catechol (TBC) on UV-stimulated melanocytes on the flanks and naturally active melanocytes of ears were compared in Uscd strain hairless mice. UVB [middlewave UV] irradiation, 2/wk for 1 or 2 mo. induced brown-black pigmentation on the flanks. A 1 M TBC application 2/wk for 2 mo. prevented UV-stimulated pigmentation and promoted fading of post-UV tanning. Dopa-stained split epidermal sheets showed a decrease in the number of melanocytes to < 1/2 during the 1st mo. of TBC treatment. Melanocytes were often enlarged or lost their dendrites and premelanosomes and melanosomes showed ultrastructural changes. TBC application on the ears for 1 mo. did not show color change or decreased number of melanocytes. There were ultrastructural changes in melanocytes but the degree of abnormality was less than those seen in UV-stimulated melanocytes. Continuation of TBC application for 2 mo. with the UV irradiation on the flanks or the nonirradiated ears caused increased number of melanocytes. The initial effect of TBC may be primarily cytotoxicity to melanocytes and may correlate with their cellular functions. Stimulatory effects of TBC on melanocytes seen during the longer period of time required further investigation.