Figure 7.

Oestradiol provided exogenously to differentiating primary human keratinocytes increases production of CER[NS] and CER[NDS]. Differentiating keratinocytes (cultured in 1.8 mM Ca²⁺) were treated with oestradiol (10 nM, 72 h). Individual ceramides were then extracted and analysed by ultraperformance liquid chromatography with electrospray ionisation and tandem mass spectrometry and grouped by ceramide class. Total CER[NS] and CER[NDS] are presented (a) as well as individual ceramides with a 18-carbon sphingosine base (b) and a 16-carbon sphingosine base (c). Data are presented as percentage of untreated control for each keratinocyte donor. *P < 0.05, analysed by paired t tests corrected for multiple testing using the Holm–Šídák method, n = 3 different keratinocyte donors.