Wertz P W, Downing D T
Department of Dermatology, University of Iowa College of Medicine, Iowa City 52242.
J Lipid Res. 1990 Oct;31(10):1839-44.
The time course of linoleic acid metabolism in porcine epidermis has been studied in order to better evaluate the lipid transformations that accompany differentiation in this tissue. One day after intradermal injection of [U-14C]linoleic acid, most of the radioactivity in the epidermis was associated with phospholipids, triglycerides, and free fatty acids. Within 3-7 days, a portion of the radiolabel was selectively transferred to acylglucosylceramide and acylceramide fractions, after which the specific activities of all lipids fractions decreased. The results suggest that neither the lipoxygenation of linoleate nor the hydrolysis of acylceramide to form acylacid and free sphingosine are major routes of linoleate metabolism in normal epidermis. The principal pathway of linoleate metabolism in normal epidermis appears to be transfer from phospholipids to acylglucosylceramide to acylceramide. The triglyceride fraction, although minor in amount, attains an initially high specific activity, and may serve as an intermediate in linoleate transfer.
为了更好地评估该组织分化过程中伴随的脂质转化，对猪表皮中亚油酸代谢的时间进程进行了研究。皮内注射[U-14C]亚油酸一天后，表皮中的大部分放射性与磷脂、甘油三酯和游离脂肪酸相关。在3至7天内，一部分放射性标记物被选择性地转移到酰基葡糖神经酰胺和酰基神经酰胺组分中，此后所有脂质组分的比活性均下降。结果表明，在正常表皮中，亚油酸的脂氧合作用以及酰基神经酰胺水解形成脂肪酸和游离鞘氨醇均不是亚油酸代谢的主要途径。正常表皮中亚油酸代谢的主要途径似乎是从磷脂转移到酰基葡糖神经酰胺再到酰基神经酰胺。甘油三酯组分虽然数量较少，但最初具有较高的比活性，可能是亚油酸转移的中间体。
