The purpose of this investigation was to study the cellular localization of fluorescent materials in the skin of mice painted with cigarette “tars” (smoke condensates), using the method of fluorescence microscopy to examine frozen sections of skin. Cigarette tars of the following categories were tested in this manner: whole tar (nicotine-free); neutral fraction; carbon tetrachloride fraction; acidic fraction; and water-soluble fraction. The cigarette tars in the first four categories, known to be active in epidermal oncogenesis in the mouse (5), displayed an affinity for lipides and keratin in the skin and, as shown by their blue-white fluorescence, apparently were passively transported down the hair follicles and promptly localized in the sebaceous glands. The inactive tar, belonging to the water- (and methanol-) soluble fraction, failed to reach and to enter the sebaceous glands to any extent comparable to that shown by the active tars.
This work was supported by a special purpose research grant from the American Cancer Society.