LIPOGENESIS IN HUMAN SKIN .4. IN VITRO RATE STUDIES

[摘要] In vitro lipogenesis from acetate-l-Cl4 by human skin was constant for time intervals from 30 min. to 6 hr. However, in human subcutaneous adipose tissue, the rate of fatty acid synthesis declined rapidly during the first 20 min. period, and squalene and cholesterol were not synthesized even after incubation for 60 min. Fatty acid synthesis was many times more rapid in adipose tissue than in skin. Despite this difference in lipogenesis in human skin and adipose tissue, both tissues showed a similar pattern of pre-formed and labeled fatty acids separated by gas chromatography. Before incubation the ratio of oleic to palmitic acid was 2 to 1; whereas, after incubation the ratio of labeled oleic to palmitic acid was 1 to 3. The reasons for this difference may be that fatty acid synthesis occurs in more than one compartment of the cell and that oleic acid is largely of dietary origin.