In the present study, the distribution of various sugar residues in skin and nasolabial glands of the muzzle region of the Egyptian water buffalos were investigated by light microscopic histochemical methods, particularly lectin histochemistry. The epidermis and nasolabial glands were labeled with all lectins under investigation (LCA, ConA, PNA, RCA120, WGA, DBA, UEA-I, MAA, SSA and PHA- E) except the MAA and UEA-I which were negative in the epidermis and in the secretory acini respec- tively. Lectins labeling of the epidermis revealed the presence of mannosyl (LCA, ConA), galactosyl (PNA, RCA120), N-acetyl-glucosamine (WGA), N- acetyl-galactosamine (DBA, PHA-E), L-fucose (UEA-1) and neuraminic acid (SSA). Interestingly, most layers of the epidermis exhibited different degrees of lectin labeling except the stratum cor- nium which showed negative reaction to all lectins. Similarly, the nasolabial glands revealed the pres- ence of mannosyl (LCA, ConA), galactosyl (PNA, RCA120), N-acetyl-glucosamine (WGA), N-acetyl- galactosamine (DBA, PHA-E) and neuraminic acid (MAA, SSA) while did not show any binding sites for L-fucose (UEA-I). The excretory ducts labeling were moderate to weak for all used lectins with two main features; firstly the present of basal striation resemble the striated ducts of salivary glands, se- condly the lectin labeling was mainly confined to the luminal surface of their cells.
In conclusion, the complex carbohydrates with var- ious sugar residues found in the epidermis and nasolabial glands of the muzzle region of buffalo may be involved in important functions, such as the preservation of humidity on the skin surface and the protection of the epidermis against physi- cal damage or bacterial invasion. In addition, our results support the view of a salivary nature of the nasolabial glands in buffalo and emphasis that the functional significance of these glands type is not functionally different from that in other bovidae.