Poll glands of the one-humped camel (Camelus dromedarius): a histochemical and scanning electron microscopic study

Poll glands of the one-humped camel were obtained to examine their secretory mechanism by lectin histochemistry, immunohistochemistry and scanning electron microscopy. The glands were composed of numerous conical lobules which consisted of apocrine tubules. Lectins of peanut agglutinin (PNA), Dolicos biflorus agglutinin (DBA) and wheat germ agglutinin (WGA) showed a variety of staining in the Golgi areas and secretory granules in secretory cells of the apocrine tubules. Most myoepithelial cells stained intensely with a-smooth muscle actin. Varicose nerve fibers immunostained with protein gene product 9.5 were scattered among apocrine tubules. Scanning electron microscopy revealed that the luminal surface of secretory cells was covered with microvilli and that secretory cells pinched off smooth-surfaced apocrine blebs. After pinching off, crater-like pits remained on the luminal surface of secretory cells. These findings are similar to those obtained from the infraorbital glands of the serows.