Salivary Gland Morphology after α-Adrenergic and Cholinergic Stimulation: An Ultrastructural Study

Abstract

The submandibular glands in 100 rats were subjected to different sialagogues: carbachol, clonidine, noradrenalin, and cyclocytidine. The morphological effects of these drugs were compared ultrastructurally. Clonidine, which is an α-2-agonist affected mostly the mucous cells, with formation of cytoplasmic vacuoles between the mucous droplets. Noradrenalin and cyclocytidine, both α-1-agonists, showed depletion of secretory granules in the serous cells. Noradrenalin also induced cytoplasmic disorganization with enlarged mitochondria, irregular endoplasmic reticulum, and shrinking of the secretory lumen. Carbachol, a cholinergic agonist, was found to produce widespread vacuolization in the cytoplasm of both serous and mucous cells. Small vesicles appeared and mitochondria were destroyed. To induce experimentally a complete depletion of granular serous cells, without other changes in Ultrastructural morphology, cyclocytidine was found to be the most efficient drug.

Key Words:

• rat submandibular gland
• sialagogues
• ultrastructure