Anatomical, histological and histochemical observations and changes in the poll glands of the camel (<i>Camelus dromedarius</i>)

Abstract

This study deals with the anatomical, histological and histochemical observations and the changes in the poll glands due to age, seasonal variations and castration. The male camels had two poll glands, one on either side of the mid-line of the poll region. The glands were present in the male camels at birth, while no visible glands were observed in the she-camels at any age. The weight and dimensions of the glands increased with age in the uncastrated camels, but the glands regressed after castration. The active glands were compound tubulo-alveolar glands. The tubules and alveoli were lined by simple squamous to high cuboidal epithelium depending on the secretory stages. The mild PAS-reactive apical blebs of the secretory cells were also positive for acid mucopolysaccharides and alkaline phosphatase. The myoepithelial cells around the alveoli and small ducts were PAS-negative. The intralobular ducts were lined by simple cuboidal epithelium. The stratified cuboidal epithelium lining the initial portion of the excretory duct abruptly changed into the stratified squamous epithelium which continued with the cutaneous epithelium of the skin. The ducts opened into the neck of the hair follicles above the level of the sebaceous ducts. The glands appeared to be modified apocrine sweat glands in the histological appearance. The interglandular connective tissue was reduced to thin strands during the winter months while, comparatively, in the summer months, the connective tissue increased. During the winter months of December to March the pungent coffee-coloured secretion from the glands was most profusing in those camels who were apparently in rut. The tubules and alveoli in such glands were lined by high cuboidal cells with apical blebs. During the summer months, the secretion was scanty except in severe exercises, and the glandular epithelium varied from simple squamous to low cuboidal.