Effect of diethylstilbestrol on skin sterols of the male rat.

Diethylstilbestrol (DES) was injected in doses ranging from 600 micro g to 0.4 micrograms/kg body weight into mature male rats over a 3 wk period. Profound effects on skin morphology and on sterol content of skin were noted. The sebaceous glands atrophied and the epidermis lost granularity. The concentrations of all skin sterols, with the exception of cholesterol, were reduced. At a dose level of DES of 4 micrograms/kg there was still a perceptible reduction in the concentration of Delta(7)-cholestenol. Incubation of skin fragments with acetate-2-(14)C for 2 hr demonstrated a reduced uptake of (14)C into the nonsaponifiable fraction of skin lipids at all dose levels studied. Preliminary thin-layer chromatography of the nonsaponifiable fraction revealed that the uptake of (14)C into cholesterol was only slightly decreased; uptake into cholesterol precursors was decreased somewhat more. The epidermis and dermis were separated by incubation of skin with elastase and hyaluronidase. The epidermis contained at least three times as much sterol per mg dry weight as did the dermis. Unesterified cholesterol was the major sterol present in both layers; the other sterols were present mainly as esters. DES injection resulted in no change in the free sterol content but markedly reduced the ester content of the epidermis and dermis.