Innervation of the rat harderian gland by adrenergic and cholinergic nerve fibres

Abstract

The innervation of the rat Harderian gland was studied using histochemical methods for catecholamines and acetylcholinesterase (AChE). Selective denervations were performed to investigate the neural connections of this gland with various ganglia. Light microscopically the AChE-positive nerves seemed to run as thick bundles in the intertubular connective tissue. These bundles sent finer branches around the acini. The blood vessels, localized in the connective tissue septa, were surrounded by a dense plexus of AChE-containing fibres. By electron microscopy, the AChE-positive fibres were seen to terminate near the myoepithelial cells surrounding secretory cells. These fibres were also observed in contact with the blood vessels and occasionally close to the secretory cells. Fluorescent adrenergic nerves surrounded the blood vessels. Some fibres were also observed in the interlobular tissue. All the AChE-containing nerves degenerated after cutting the zygomatic nerve. On the other hand, removal of the ciliary ganglion or the superior cervical ganglion, or stereotactic coagulation of the ophthalmic nerve did not affect these nerves. The fluorescent adrenergic fibres disappeared following both removal of the superior cervical ganglion and coagulation of the ophthalmic nerve. These fibres were intact after removal of the ciliary ganglion.

Ultrastructural observations on myoepithelial cells and nerve terminals in the camel Harderian gland

“…However, in rabbits and hamsters, nerve terminals are in contact either with secretory or myoepithelial cells (Sakai 1981). Denervation experiments of Huhtala et al (1977) revealed that nerve terminals associated with end-pieces are cholinergic in nature, and of parasympathetic origin.…”

The avian Harderian gland: Morphology and immunology

“…In mammals, Huhtala et al (1977) also observed AchE-positive nerves along the blood vessels of the rat Harderian gland, while Norvell and Clabough (1972) did not find such in the hamster. The latter authors suggested that the modification of blood flow in the hamster gland is mainly due to adrenergic fibers.…”

Comparative histological and ultrastructural studies of the Harderian gland of rodents

“…meridianus (Sakai and Yohro, 1981). Huhtala et al (1977) demonstrated that the rat Harderian gland receives both cholinergic and adrenergic nerves. The clear vesicles contained in the nerve endings located just outside the basal lamina of the tubules may release transmitter substances which diffuse through the basal lamina and may stimulate myoepithelial cells, epithelial cells, or both, promoting the release of the glandular secretion.…”