Histology of the venom gland of the puff-adder (Bitis arietans)

Abstract

The histology of the venom gland of the puff-adder (Bitis arietans) has been investigated in the resting and stimulated state. No accessory venom gland was found to be associated with the main venom gland or duct in the same position as has been reported for other snakes. In the resting state the parenchyma of the venom gland was found to consist of tubules lined by a single layer of tall columnar secretory cells. After being stimulated to secrete by repeated milkings, the histological appearance of the gland changed and the epithelium was found to be more foliaceous and the component cells to be taller and more slender. A pronounced increase of pigment was also observed in the connective tissue septae. Micro-organisms were observed in the secretion pools of resting glands and by culturing the venom it could be shown that these were Staphylococcus aureus, Staphylococcus epidermidis and Klebsiella ozaenae. The presence of these organisms would suggest that the venom is not cytotoxic to all cells at this level of production.