CARCINOGENS SHOW COMEDOGENIC ACTIVITY - A POTENTIAL ANIMAL SCREEN FORTUMORIGENIC SUBSTANCES

Formation of a comedo, an impaction of horny cells in sebaceous follic les, entails a metaplastic change in the differentiation patterns of t he follicular epithelium. Since metaplasia is a requisite early stage in carcinogenesis, we postulated that carcinogens might be comedogenic . The rabbit ear was used to assay the comedogenic potentialities of a n array of known tumorigens. Complete carcinogens and some tumor promo ters were invariably strongly comedogenic at concentrations of 1.0% an d below. Comedogenic chemicals commonly found in skin care products us ually required concentrations of 40% and greater to induce comedones w hich were small in comparison to carcinogen induced comedones. We sugg est that the rabbit ear model might be an easy and reliable way to scr een for carcinogenicity.