ON THE SPECIFICITY OF THE RESPONSE OF MOUSE EPIDERMIS TO VITAMIN-A

[摘要] Topical application of small amounts of vitamin A to the skin of C57B1 Crgl mice caused epidermal hypertrophy, and in amounts of 1-100 units daily the epidermal hypertrophy was porportional to the log of the dose. During telogen moderate amounts of vitamin A caused thickening of the upper outer hair follicle sheath: in anagen there was an overall increase in the length of the follicle. These changes in the follicle were not noted in the lowest dosages needed to stimulate epidermal hypertrophy. Moderate amounts of other substances (aqueous vehicle, oleic acid, cysteine hydrochloride, mercaptoethanol, alpha toluenethiol, and beta carotene) produced no epidermal hypertrophy. Hard keratin areas of mouse tail when treated with vitamin A showed histological soft keratin epithelium.