Histology and cytochemistry of skin gland areas in the caribou, Rangifer

Quay, WB

Skin samples of an adult male and an adult female caribou, collected in April in northern Alaska and fixed in formalin-alcohol, were studied histologically and cytochemically. The skin samples represent four specialized areas: the tarsal gland, the fore- and hind foot interdigital glands, and the preorbital pocket. All of these areas contain both sebaceous and apocrine sudoriferous glands. The glandular development in these areas is the same in both sexes, except for the tarsal gland, which is considerably greater in surface area, thickness, and glandular development in the female. The glandular elements of the interdigital glands are highly developed, but those of the preorbital pocket are poorly developed. The cytochemistry of the apocrine cells of the tarsal gland is distinguished from that of the interdigital glands by the lack of lipofuscin and presence of aldehyde groups in the cytoplasm and by the presence of aldehydes, basophilia, and greater sudanophilia in secretion globules. Glycogen is identified in many of the apocrine cells of the hind foot interdigital glands on the basis of staining with periodic acid leuco-fuchsin and removal by diastase. Material of similar appearance and staining capacity, but not tested with diastase, is found in apocrine cells of other areas. Neither ferric nor ferrous iron could be demonstrated in the apocrine cells of these areas. Further details of histology and cytology are described and possible functions of the glandular areas are discussed.

Histology and cytochemistry of skin gland areas in the caribou, Rangifer

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