Microscopic anatomy of the skin or the woodchuck (Marmota monax): comparison of woodchuck hepatitis virus-infected and non-infected animals [Anatomie microscopique de la peau de la marmotte (M. monax) : comparaison des animaux infectés et non-infectés par le virus de l'hépatite.

Résumé

Thirty-three woodchucks were used in this study. Seventeen animals were healthy adults, not infected with woodchuck hepatitis virus (WHV). 10 were healthy adults infected with WHV. 4 were noninfected neonates. 2 were infected neonates. Within the 4 groups of woodchucks, no histologic differences were detected on the basis of sex or age. Neither were histologic findings different between infected and noninfected woodchucks of similar ages. The average thickness of skin (as measured from the skin surface to the inner limit of the dermis) from the general haired body area was 2394 microm. The skin was thickest on drsal body areas, and gradually became thinner on ventral body and medial limb areas. The epidermis consisted of 4 layers: stratum basale, stratum spinosum, stratum granulosum, and stratum corneum. A stratum lucidum was present only in the epidermis of the footpads. There was no clear distinction between the superficial dermis and the eep dermis, except for the subtle differences in arrangement and size of collagen fibers. Elastic fibers were seen throughout the dermis, being more prominent in the superficial portion. Both compound and simple hair follicle arrangments were seen, with compound being more common. The arrectores pilorum muscles were largest in the skin over the dorsal body areas. Sebaeous glands were present either within the outer root sheath of hair follicules or in the enses connective tissue surrounding hair follicles. No apocrine sweat glands were found. However, there were abundant eccrine sweat glands in the subcutaneous fat of the footpads.