Al-Saidan S M, Winfield A J, Selkirk A B
School of Pharmacy, Robert Gordon's Institute of Technology, Aberdeen, Scotland.
J Invest Dermatol. 1987 Oct;89(4):430-3. doi: 10.1111/1523-1747.ep12471786.
We heated flat sheets of neonatal rat stratum corneum for various times at temperatures between 40 and 90 degrees C before determining the permeability coefficient (Kp) of propanol and/or hexanol from water. Below 70 degrees C, Kp remained constant; at 75 degrees C, Kp increased linearly with exposure time; at 80 degrees C and above, there was a large increase in under 2 h, with no further increase on longer heating. There was a 15-fold increase in 6-h Kp between 70 degrees C and 80 degrees C, values being constant above 80 degrees C but at a figure less than for lipid-extracted stratum corneum. Thermal analysis showed that the increase in Kp corresponds to changes in the 80 degrees C lipid endotherm, suggesting that the increased Kp is due to a disordering of the lipid structures. The effect of treating preheated stratum corneum with dimethylsulfoxide (DMSO) vapor for 16 h was also studied. Below 70 degrees C, Kp was increased five-fold, but between 70 and 80 degrees C this difference was eliminated, so that above 80 degrees C the Kp was the same as with heat treatment alone. We concluded that both heat and DMSO affect the lipid structures of stratum corneum. DMSO produced a small, reversible structural change, while the effect of heat is irreversible and produces a greater degree of disorder in the lipid structures, but the lipid still contributed to the barrier effect of stratum corneum.
在测定丙醇和/或己醇从水中的渗透系数（Kp）之前，我们将新生大鼠角质层的平片在40至90摄氏度之间的温度下加热不同时间。在70摄氏度以下，Kp保持恒定；在75摄氏度时，Kp随暴露时间呈线性增加；在80摄氏度及以上，在2小时内Kp大幅增加，长时间加热后不再进一步增加。在70摄氏度和80摄氏度之间，6小时的Kp增加了15倍，80摄氏度以上的值保持恒定，但低于脂质提取的角质层的值。热分析表明，Kp的增加对应于80摄氏度脂质吸热峰的变化，表明Kp的增加是由于脂质结构的无序化。还研究了用二甲亚砜（DMSO）蒸汽处理预热角质层16小时的效果。在70摄氏度以下，Kp增加了五倍，但在70至80摄氏度之间这种差异被消除，因此在80摄氏度以上，Kp与仅热处理时相同。我们得出结论，热和DMSO都会影响角质层的脂质结构。DMSO产生了微小的、可逆的结构变化，而热的影响是不可逆的，会在脂质结构中产生更大程度的无序，但脂质仍然对角质层的屏障作用有贡献。
