Is Endogenous Glycerol a Determinant of Stratum Corneum Hydration in Humans?  Eung Ho Choi, Mao-Qiang Man, Fusheng Wang, Xinjiang Zhang, Barbara E. Brown, Kenneth R. Feingold, Peter M. Elias  Journal of Investigative Dermatology  Volume 125, Issue 2, Pages 288-293 (August 2005) DOI: 10.1111/j.0022-202X.2005.23799.x Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 1 Stratum corneum (SC) hydration, sebum content, and SC glycerol content in normal Chinese subjects. SC hydration was measured as electrical capacitance (corneometer), and surface lipid (sebum) content was assessed with a Sebumeter. Glycerol content reflects the total nmol per 5 sequential D-squame strips. Comparisons are for sebaceous gland (SG)-enriched (forehead) versus SG-impoverished (shin) skin sites (data shown are for both genders). Journal of Investigative Dermatology 2005 125, 288-293DOI: (10.1111/j.0022-202X.2005.23799.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 2 Stratum corneum (SC) hydration and SC glycerol content in San Francisco (SF) cohorts. Both SC hydration (A) and glycerol (B) content significantly increase in sebaceous gland (SG)-enriched (upper back) versus SG-impoverished (shin) skin sites in adults (p-value<0.05). In prepubertal children, however, both parameters do not increase in SG-enriched skin compared with SG-impoverished skin (C, D). Journal of Investigative Dermatology 2005 125, 288-293DOI: (10.1111/j.0022-202X.2005.23799.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 3 Stratum corneum (SC) hydration correlates with SC glycerol content (San Francisco cohort). SC hydration correlates significantly with SC glycerol content in both sebaceous gland-enriched (upper back) and -impoverished (shin) skin sites. Each data point corresponds to a different subject (linear regression analysis). Journal of Investigative Dermatology 2005 125, 288-293DOI: (10.1111/j.0022-202X.2005.23799.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 4 Bathing removes stratum corneum glycerol (San Francisco cohort). Glycerol levels were assessed immediately before and immediately after bathing, and at 6, 24, and 48 h after bathing (24–48 h data not shown). Journal of Investigative Dermatology 2005 125, 288-293DOI: (10.1111/j.0022-202X.2005.23799.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions

Figure 5 Stratum corneum (SC) hydration and glycerol content decline in parallel with water immersion (San Francisco cohort). Circumscribed area on subject forearms (n=8) were exposed for 20 min to water-soaked cotton pads, air-dried at room temperatures for 15 min, and then both SC hydration and glycerol content were measured. Dotted line represents pre-immersion levels. Journal of Investigative Dermatology 2005 125, 288-293DOI: (10.1111/j.0022-202X.2005.23799.x) Copyright © 2005 The Society for Investigative Dermatology, Inc Terms and Conditions