ANATOMY AND CHOLINERGIC INNERVATION OF THE SINUS PARANALIS IN DOGS

Conventional methods have been used to study the general configuration of the wall of the Sinus paranalis in dogs. Apocrine tubular glands, elastic fibres and smooth-muscle fibres are the more significant eleme nts of the wall, together with the epithelium and connective tissue. B y means of the immunohistochemical method described in this paper, the results provide histochemical evidence for the presence of an AChE-po sitive reaction, and supposedly cholinergic nerve fibres in the wall o f the dog anal sacs, mainly associated with subepithelial smooth muscl e, vessels, and glands.