Partial purification of a low molecular weight inhibitor of epidermal DNA synthesis

Abstract

Abstract. An attempt has been made to purify factors present in aqueous extracts of pig epidermis which inhibit epidermal cell proliferation. A lipophilic factor of low molecular weight (less than 10,000), has been shown to inhibit DNA synthesis as measured by the uptake of tritiated thymidine in mouse ear epidermis. Purification by alcohol precipitation, ethyl acetate extraction and silicic acid column chromatography produced a fifteen‐fold increase in the specific activity of the inhibitory action. It seems likely that aggregation or absorption of this low molecular weight factor may explain the high molecular weight of epidermal cell proliferation inhibitors previously studied, as well as the difficulty in their characterization.

Inhibition of Growth of Hair Follicles by a Lectin-like Substance from Rat Skin

“…One of the main problems in assaying for chalone activity in skin extracts is that inhibitory activity tends to be found spread over a wide range of fractions, and it has recently been suggested that a low molecular weight substance may bind to several types of larger species, and thus appear in several fractions from gel filtration or ion-exchange chromatography (Quirk et al 1982). These workers proposed that the active substance was a lipid, and began with an ethanolic extraction of epidermal scrapings from slaughtered pig skin.…”