Downing D T, Stranieri A M, Strauss J S
J Invest Dermatol. 1982 Oct;79(4):226-8. doi: 10.1111/1523-1747.ep12500066.
When sebum is collected from the skin surface in an absorbent material, the amounts obtained in successive collections at the same site decline steadily. In the present study, sebum was absorbed into bentonite clay applied to 2.5 sq cm areas on the foreheads of 3 subjects for 3-hr intervals during 24 hr. The amounts of sebum obtained, measured by thin-layer chromatography, declined for 12 hr and then remained constant for the remaining 12 hr. It was inferred that the final, sustainable rate represents the true rate at which sebum was being secreted by the sebaceous glands, and that the additional sebum collected at earlier intervals was obtained from an accumulation in the stratum corneum or in the follicular canals. For the 3 subjects, the accumulated sebum averaged 213 micrograms/sq cm, compared with a sustainable secretion rate of 25 micrograms/sq cm/hr. The large quantity of accumulated sebum, relative to the secretion rate, could obscure differences between subjects when sebum secretion rates are measured by short-term collections of sebum in absorbent materials.
当用吸收性材料从皮肤表面收集皮脂时，在同一部位连续收集得到的皮脂量会稳步下降。在本研究中，将膨润土应用于3名受试者前额2.5平方厘米的区域，每隔3小时收集一次皮脂，持续24小时。通过薄层色谱法测定得到的皮脂量在12小时内下降，然后在剩余的12小时内保持恒定。据推测，最终的可持续速率代表皮脂腺分泌皮脂的真实速率，而在较早时间段收集到的额外皮脂是从角质层或毛囊管中的积聚物中获取的。对于这3名受试者，累积皮脂平均为213微克/平方厘米，而可持续分泌速率为25微克/平方厘米/小时。相对于分泌速率而言，大量的累积皮脂可能会掩盖在通过用吸收性材料短期收集皮脂来测量皮脂分泌速率时受试者之间的差异。
