Mitotic Inhibition of Epidermal Cells From Psoriasis Lesions In Vitro by Extracts From Normal Human Skin2

Abstract

Previously it was shown that mitosis of normal human epidermal cells in vitro was regulated in part by a tissue-specific mitotic inhibitor (chalone). The present study demonstrated that epidermal cells from psoriasis lesions, a condition of benign epidermal hyperplasia, were also inhibited by normal skin extract in vitro. This inhibition was tissue specific, since liver extract had no effect. It is concluded that excessive proliferation of psoriatic epidermal cells is not due to failure of target-cell response to epidermal chalone.