Indexed on: 01 Dec '73Published on: 01 Dec '73Published in: Virchows Archiv. B, Cell pathology including molecular pathology
Recent results have shown that water extracts of mouse skin contains two separate inhibitors of epidermal cell proliferation. One of these inhibitors acts on epidermal cells in the late part of the G1 phase and is probably produced by the keratinizing cells. The other factor acts on epidermal G2 cells and can be extracted from isolated basal layer cells. In the present study it was found that water extracts made from rat dermis inhibited mouse epidermal G2 cells but not those in late G1 phase. This effect is similar to that of the epidermal G2-inhibitor extracted from basal layer cells. Intraperitoneal injection of mouse serum had no effect on epidermal cell proliferation but the G2-inhibiting activity of crude skin extracts was reduced or lost when dissolved in fresh serum. The G1-inhibitmg activity was only slightly reduced by fresh serum. Heated serum had no influence on either inhibitor. These results indicate that dermis and blood could be involved in the normal removal of the epidermal chalone. The findings are discussed in relation to epidermal growth and differentiation, and to the role of serum in sustaining growth in vitro.