Growth suppression of hamster flank organs by topical application of gamma-linolenic and other fatty acid inhibitors of 5 alpha-reductase

[摘要] Certain unsaturated aliphatic fatty acids, such as gamma-linolenic acid, inhibit 5 alpha-reductase activity in vitro and in vivo. Hamster flank organ growth, as measured by the increase in the area of pigmented macule, is dependent on androgen, When one of the paired flank organs of a castrated hamster was treated topically with testosterone, the treated organ, but not the contralateral flank organ, became larger and darker. Topical application of gamma-linolenic acid to the testosterone-treated flank organ suppressed this testosterone effect. Other fatty acids that were not inhibitors of 5 alpha-reductases were not active. Topical treatment of hamster flank organs with 5 alpha-dihydrotestosterone also stimulated the growth of the organ. This 5 alpha-dihydrotestosterone-dependent activity, however, was not significantly affected by gamma-linolenic acid, suggesting that flank organ growth was dependent on 5 alpha-dihydrotestosterone and that gamma-linolenic acid acted by inhibiting 5 alpha-reductase. With intact male hamsters, the endogenous androgen-dependent growth of flank organs is also suppressed by topical treatment with gamma-linolenic acid, The effect of gamma-linolenic acid is localized at the site of its application; topical application of gamma-linolenic acid did not affect the androgen-dependent growth of other organs such as testis, epididymis, seminal vesicle, and prostate, gamma-linolenic acid, with low toxicity and absence of systemic effect, therefore may be potentially useful for treatment of androgen-dependent skin disorders.

[发布日期] 1997-08-01

[关键词] androgen;unsaturated fatty acids;hair;melanocytes