Characterization of Normal Skin Thickness for Various Body Regions, Ages and Genders of Yucatan Miniature Swine
Brown, L., Kim, D.Y., Hanks, C., Brocksmith, D., Hodges, M., Liu, J., Bouchard, G.F.
Dermatology is an extremely important field as the skin of humans and animals plays a life sparing protective role. The skin is the largest organ of the body and is metabolically active. Skin is constantly undergoing changes of shedding and regeneration. Skin from various regions of the body may vary morphologically, including physical thickness. Dermatological studies in miniature swine provides a unique opportunity for risk assessment because of demonstrated similarities to human cutaneous anatomy, biochemistry, and physiology. The Yucatan is a popular miniature pig in use in biomedical research today. Yucatan skin is slate grey-black in color, slight-moderately pigmented, and contains a sparse hair coat (sometimes called the Mexican Hairless Minipig). The physical thickness of miniature pig skin may impact drug absorption during in vivo or ex vivo studies, or affect wound healing or phototoxicity studies, therefore a good understanding of the relative dimensions of each major skin application or collection site is indicated. This study of Yucatan skin was undertaken to better document this area because researchers are asking about skin thickness of minipigs. Few citations on porcine or minipig skin thickness exist. Eggleston et al. (2000) reported mean ±SD thickness of the Yucatan minipig flank and dorsal neck epidermis were 68 ±34 and 68 ±-25 μM, respectively. Thickness of the Yucatan minipig skin were closely comparable to the thickness of human epidermis from the face (68 ±26 μM), neck (65±24 μM) and arms (68 ±21 μM). The domestic Yorkshire epidermis from 7 sites was not as thick (Eggleston et al., 2000). Monteiro-Riveireet al. (1990) reported back skin components of the domestic Yorkshire swine including a 12.28 ±0.72 μM strateum corneum, 51.89 ±1.49 μM cellular epidermis and 3.94 ±0.13 epidermal cell layers. Grabauet al. (1995) reported on a laboratory histological survey of research animal skin thickness, including a mixed breed domestic farm pig. This study will add additional Standard Yucatan Minipig data to the research database.