Influence of prostaglandins E1, E2, and arachidonate on melanosomes in melanocytes and keratinocytes of anagen hair bulbs in vitro.

Anagen hair bulbs were collected and maintained in organ culture for periods up to 24 hr. Prostaglandin E1, E2 and arachidonate were introduced to the cultures and stimulated a series of cellular events characterized by peripheral orientation of microfilaments in the dendritic processes of melanocytes, complexing of melanosomes; and degradation of melanosomes within keratinocytes. These events were dependent on the concentration of prostaglandins. In addition, the most potent agent for these events was arachidonate. The action of arachidonate was hypothesized to occur through the production of endogenous prostaglandins since arachidonate was ineffective in the presence of inhibitors of prostaglandin synthetase.