Abstract
The current study was undertaken to evaluate the validity of immunohistochemistry in the proportional labeling of the diverse components of the lactating and non-lactating mammary gland in the camel (Camelus dromedarius). Paraffin-embedded sections of lactating and non-lactating mammary glands were stained by conventional and histochemical techniques. Primary antibodies against S100, alpha smooth muscle actin (alpha-SMA) and cytokeratin (Ck) were applied on paraffin sections. The spatial distribution of different proteins in the diverse compartments of lactating and non-lactating mammary tissue displayed a variable immunoreactivity (IR). The luminal epithelial cells showed binding sites only for S100 and Ck 8. The myoepithelial cells exhibited either a consistent IR (alpha-SMA) or variable IR (Ck 5 and S100). In conclusion, the intensity and distribution pattern of all proteins in the lactating gland are greater than in the non-lactating one. The functional relevance of the findings is interpreted. S100 and Ck proteins participate in secretory activities and in maintaining cellular integrity of luminal cells during lactation and non-lactation phases, respectively. Immunolocalisation of alpha-SMA highlights the contractile capacities of myoepithelial cells reflecting their contractile function, Ck preserves their structural and physiological integrity at different phases, whereas the S100-IR displayed by them, especially during non-lactation phase, may lend support to the notion that myoepithelial cells provide a regenerative potential of the mammary epithelium.