Rat skin physiology is modified by age

• Main Authors: Graziela Sponchiado, C Mello-Sampayo, Maria M Pereira, Henrique Silva, MF Otuki, B Silva-Lima, Luis Monteiro Rodrigues
• Format: Article
• Language: English
• Published: ALIES - Associação Lusófona para o Desenvolvimento da Investigação e do Ensino das Ciências da Saúde 2012-12-01
• Series: Journal Biomedical and Biopharmaceutical Research (BBR)
• Subjects: Wistar rat; TEWL; ageing; hydration; biomechanics
• Online Access: http://www.alies.pt/BBR%20Editions/Vol-9-2-2012/Article8_9n2.pdf
• ISSN: 2182-2360; 2182-2379

Animal models have been useful in the study of specific mechanisms affecting human skin. Such is the case with ageing and the micromechanical changes determining wrinkles in UV- irradiated mice. These models enabled us to understand that ageing encompasses many peculiar mechanical responses which cannot be explained by homogeneous deformation of the skin. Moreover, a major aspect to consider is that ageing processes differ among species and direct inferences are rarely possible. This project aimed to compare age-induced changes in skin properties by studying two Wistar rat groups of different ages – young adult rats (n=7, 20–24 week-old) and old adult rats (n=5, 48–72 week-old). Non-invasive measuring approaches involving transepidermal water loss (TEWL), superficial hydration (MoistureMeter), and biomechanics (Reviscometer, and Cutometer by MPA80) were taken in the animal dorsum (neck, bottom) over a period of five days, allowing statistical comparisons between groups. Results revealed no significant differences for TEWL, firmness or viscoelasticity between the two groups. However, a significant hydration decrease, of nearly 40%, was noted in the old adult rats group. These results, although preliminary, if translatable to humans could be useful to address age-related changes in processes such as healing, or patch dressing efficacy/safety where hydration is a critical determinant. Their potential use for the prediction of efficacy and or safety of topically applied products for the elderly as compared to young adults may warrant further investigation..