3 Intraductal injection of botulinum toxin induces functional changes in the rat submandibular gland cells

Abstract

Intraductal injection of botulinum toxin (BoNT) induces a transient denervation of the submandibular gland. The submandibular glands of male Wistar rats weighing 250-300g were injected with BoNT. Morphological and ultra structural analyses of the cell organelles and secretory granules showed clear atrophy of the acini in the experimental animals. Morphometric measurements of the glandular acini revealed a significant reduction in the area of the acinar cells after injection of BoNT. The expression of amylase was significantly reduced in the BoNT treated glands. These effects may be caused by glandular denervation induced by the inhibition of the soluble N-ethylmaleimide-sensitive fusion protein attachment protein receptors (SNAREs) involved in acetylcholine release at the neuroglandular junction. In particular, these effects may also be caused by inhibition of those receptors involved in exocytosis of the granules of the acinar cells.