Lipogenesis by isolated human apocrine sweat gland: Testosterone has no effect during long-term organ maintenance

Abstract

Lipid synthesis by freshly isolated human apocrine glands has been measured by the incorporation of [U-14C] acetate. Incorporation is linear over 6 h at 1010 ± 282 pmol/mg wet weight/h (n = 11; mean ± sem). The lipid classes, as percentages of the total lipid synthesized, were found by TLC to be cholesterol 12.3 ± 2.0, mono-glycerides 7.5 ± 1.5, 1,2 di-glycerides 3.0 ± 0.9, 1,3 di-glycerides 3.5 ± 0.5, tri-glycerides 28.4 ± 1.8, free fatty acids 2.0 ± 0.4, lysolecithin 15.4 ± 3.9, sphingomyelin 9.9 ± 4.3, phosphatidyl-choline 8.4 ± 0.4, phosphatidyl-ethanolamine -inositol and -serine 1.8 ± 0.1, phosphatidic acid and cardiolipin 3.3 ± 0.5, and unidentified 3.3 ± 0.5 (mean ± sem, n = 5). Glands were maintained on permeable supports. After 10 d maintenance, electron microscopy showed that the cellular architecture had been preserved, that the ATP contents were the same as in freshly isolated glands, and that [U-14C] acetate incorporation was not significantly altered at 851 ± 237 pmol/mg/h (n = 18). The addition of 3 μM testosterone had no effect on acetate incorporation at 844 ± 231 pmol/mg/h (n = 18). The lipid classes and their proportions were similar to the values for fresh glands after 10 d maintenance both with and without testosterone.