Comparison of Skin Histology between SD Rats and BAMA Minipig

Objective To observe the normal histology of skin in SD rat and BAMA minipig.Methods The skins are removed from SD rat and BAMA minipig,then fixed with 10% formalin,embedded with paraffin,stained with HE and observed under light microscope.Results Two animal skin histological structures are notably different in the following areas: 1.The hair follicles of SD rat are distributed,the average is 3-9 groups,while the hair follicles of BAMA minipig are rare;2.The periderm of SD rat is thinner and there is no diaphanotheca.The basal cell is lack of heterogeneity.The junction of dermal and epidermal is flat,which is no skin nails.while in BAMA minipig,skin nails and dermal papillas are staggered up and down.3.The structure of the dermis is relatively loose in SD rats.The vascular system is underdeveloped in dermal.However,in the junction of Bama miniature pig skin dermis reticular layer and papillary layer,a lot of the superficial plexus of small veins and arteries are distributed horizontally.The Distributed manner of the blood vessels in Bama miniature pig skin is very similar with human skin;4.Sweat glands are confined to the foot pad of SD rat,Epithelial cells of sweat gland are the only one cell type,glandular cells are cuboidal or low columnar,nucleus is round,Duct which is composed of two layers of epithelial cells is short and curved.However,the sweat glands in the Bama minipig are named apocrine sweat glands.Porcine sweat glands are located in the deep dermis which is connected by dermis and fat.The secretory portion is wide,lumens is large,and is coiled into the group.Gland cells are cube or flat,nucleus is round or fusiform shape.There are myoepithelial cells between the gland cells and the basement membrane.The ducts are fine and straight,which are opened to the upper hair follicle.