Physiological factors that alter the concentrations of skin sterols: Δ 7-cholestenol as an indicator of sebaceous gland activity

Abstract

The effects of endocrine gland extirpation and of treatment with hormones and unsaturated lipides on the skin sterols of mice were investigated. Concentrations of Δ 7-cholestenol, a sterol localized in sebaceous glands, were depressed by castration of males or by pituitectomy. The concentration of Δ 7-cholestenol in castrated mice was elevated by injections of estradiol benzoate in sesame oil, and by testosterone, progesterone, or cortisone acetate in aqueous suspension. Treatment of noncastrated mice with bovine growth hormone produced some elevation of Δ 7-cholestenol. When the steroid hormones were applied topically in acetone solution, only testosterone elevated Δ 7-cholestenol. That Δ 7-cholestenol was elevated in an unspecific way by the injection of some substances was evidenced by the fact that the injection of sesame oil, squalene, or methyl linoleate also elevated this sterol, although the degree of response was less than that obtained with most of the steroid hormones. The concentration of Δ 7-cholestenol was markedly elevated by the direct application to the skin of squalene, methyl linoleate, or methyl oleate. Natural squalene that had been purified by alumina chromatography appeared to be considerably more active than after further purification by distillation or passage through a solid derivative or than the fatty acid esters. Changes in the concentration of Δ 7-cholestenol were independent of changes in the concentration of cholesterol or total acetone-soluble materials, or of changes in epidermal or dermal weight. Factors that altered preputial gland weight also altered the concentration of Δ 7-cholestenol, but changes in this sterol were not always accompanied by changes in preputial gland size. The proportion of fast-acting sterols in the sterol mixture of preputial glands was relatively unchanged by factors that caused marked alterations in preputial gland size. It appears that while known changes in sebaceous gland size and activity are generally reflected in changes in Δ 7-cholestenol concentrations, the concentration of this sterol is also increased by procedures which have not yet been shown to increase sebaceous gland size or rate of excretion.