Stewart M E, Quinn M A, Downing D T
J Invest Dermatol. 1982 Apr;78(4):291-5. doi: 10.1111/1523-1747.ep12507228.
Wax ester/sterol ester (WE/SE) ratios were measured in samples of vernix caseosa lipid obtained from 21 full-term infants. The mean WE/SE ratio was twice as high in males as in females, suggesting higher average fetal sebum production rates in males, but individual values varied widely and there was considerable overlap between the sexes. Wax esters (a class of lipid produced only by the sebaceous glands) were isolated from 6 of the 21 samples of vernix caseosa lipid and analyzed for fatty acid composition. The percentages of iso and anteiso branched saturated fatty acids and of delta 9-type monounsaturated fatty acids were found to be correlated negatively with the WE/SE ratios of the original lipid samples. Values for the percentages of the major delta 9-type monounsaturates, plotted as a function of WE/SE ratios, fell near a curve of the shape which would be expected if a limited quantity of delta 9-type monounsaturates were available for sebum synthesis, and were diluted with varying amounts of delta 6-type monounsaturates, the amount of the delta 6-type monounsaturates being proportional to the amount of wax esters synthesized by the sebaceous glands. The results suggested that the rate of sebum production may be the sole determinant of the percentage of delta 9-type monounsaturates in sebaceous wax esters and a partial determinant of the percentage of iso and anteiso branched saturates.
对从21名足月儿获取的胎脂样本测量了蜡酯/甾醇酯（WE/SE）比率。男性的平均WE/SE比率是女性的两倍，这表明男性胎儿皮脂的平均生成率更高，但个体值差异很大，且两性之间有相当大的重叠。从21份胎脂样本中的6份中分离出蜡酯（一类仅由皮脂腺产生的脂质），并分析其脂肪酸组成。发现异支链和反异支链饱和脂肪酸以及δ9型单不饱和脂肪酸的百分比与原始脂质样本的WE/SE比率呈负相关。将主要δ9型单不饱和脂肪酸的百分比值作为WE/SE比率的函数绘制，其落在一条曲线附近，该曲线形状是如果只有有限量的δ9型单不饱和脂肪酸可用于皮脂合成，并被不同量的δ6型单不饱和脂肪酸稀释，而δ6型单不饱和脂肪酸的量与皮脂腺合成的蜡酯量成比例时所预期的。结果表明，皮脂生成率可能是皮脂腺蜡酯中δ9型单不饱和脂肪酸百分比的唯一决定因素，也是异支链和反异支链饱和脂肪酸百分比的部分决定因素。
