Effects of hormonal factors and of the hereditary character hairless on the sterols of mouse skin.

The sterol A7-cholestenol constitutes a large proportion of the total sterols of rat and mouse skin (5, 7, 18). Whereas the concentration of this sterol is not altered by such factors as diet, metabolic rate (7), and ultraviolet light (13), it decreases rapidly following the application of carcinogenic hydrocarbons to mouse skin (5). This decrease coincides with destruction of the sebaceous glands (3, 9, 11), suggesting a relationship between sebaceous glands and AT-cholestenol. One method of determining such a relationship is the measurement of skin sterols in animals subjected to factors which are known to alter sebaceous glands. Testosterone produces hyperplasia of the sebaceous glands, while high doses of estrogen produce atrophy (~), and castration is followed by decreased sebaceous secretion (4, 10). The sebaceous glands of hairless mice (hr hr) become increasingly cystic with advancing age (8). The present study deals with the effects of castration and hormone treatment on the skin sterols of normal mice, and with the effects of age and of methylcholanthrene applications on the skin sterols of hairless mice.