Carbohydrate histochemistry of the epidermis of Natrix piscator during its sloughing cycle

Carbohydrate histochemistry of the scale and hinge epidermis of the chequered water snake, Nalrix piscator , throughout the sloughing cycle, has been described. The small amount of mucopolysaccharide present in the Oberhautchen, mesos layer, α-layer and β-Mayer (in its initial stage of differentiation) is comparable with that in amphibian epidermis and the epidermis of certain freshwater fish undergoing keratinization. Moderate amounts of mucopolysaccharide in the lacunar tissue and clear layer may protect against environmental pathogens and retain water to protect the epidermis from desiccation. Mucous cells could not be located in the epidermis throughout the sloughing cycle, contrary to some previous observations that they occur in the hinge region. The general absence of glycogen in the epidermis in most stages of the sloughing cycle suggests that the glycogen metabolized in the epidermis is utilized immediately, in view of the high energy requirements of proliferation and differentiation. Accumulation of glycogen granules in the presumptive α-layer in stage 2 and in the clear layer, presumptive Oberhautchen and presumptive β-Mayer in stage 3 is correlated with low energy requirements, indicating a slowing down of the process of keratinization of cells in these layers.