Leukotrienes and thromboxane B2 stimulate normal human melanocytes in vitro: Possible inducers of postinflammatory pigmentation.

Normal human epidermal melanocytes became swollen and more dendritic with an increase in the amount of immunoreactive tyrosinase when they were cultured for 2 days with each one of leukotriene (LT) C4, LTD4 and TXB2. Their effects were stronger than that of prostaglandin E2, about which we have previously reported. From these data we suggest that arachidonate-derived chemical mediators, especially LTC4, LTD4 and TXB2 may be responsible for the induction of post-inflammatory hyperpigmentation of the skin.