Histochemical and Immunohistochemical Examination of Cranial and Caudal Gland Alveolar Secretion of the Same Lactating Mammary Gland Quarter of One Humped She Camel (Camelus dromedarius)

Abstract

The differences in milk composition between different parts of the same mammary gland in camel milk have been a point of interest in previous studies. Therefore, the aim of this study is to demonstrate the differences in the distribution of carbohydrates, mucins and caseins between the cranial and caudal gland of the same lactating mammary gland quarter through testing the histochemical differences by Periodic Acid Schiff (PAS), Alcian Blue (AB), and immunohistochemical differences by α and β-casein. The examined mammary glands samples were collected from 6 healthy mature one-humped she-camels (Camelus dromedaries) on mid of lactation just after slaughtering. Sections were fixed in 10% neutral buffer formalin then subjected to the histochemical and immunohistochemical examination. The intensity of the PAS reaction differed throughout the mammary gland; the cranial gland alveolar secretion showed more intense magenta color when compared to the caudal gland. The same lactating mammary gland quarter showed darker blue alveolar secretion in cranial gland when stained with AB in comparison with the caudal one which showed significant faint colored secretion. The alveolar secretion of the cranial gland showed stronger reaction for α-and β-casein than the caudal gland alveolar secretion. The positive staining of βcasein in cranial gland was localized on the alveolar secretion as well as in most of the cells surrounding the lumen of the alveoli. In contrast, week positive staining appeared in the lumen and was not observed in alveolar cells for αcasein in cranial gland and for α and β -casein in caudal gland.