Morphological changes in salivary glands after treatment with sialagogues. An electronmicroscopical study

A dual innervation in salivary glands has been discussed. It is unclear how alpha-adrenergic and cholinergic agents stimulate the secretory cells. Different effects on serous and mucous cells are reported after stimulating with carbachol, clonidine, noradrenaline, cyclocytidine and pilocarpine, respectively. In the rat, carbachol and clonidine predominantly affect the mucous cells, however, with different morphological effects. Cyclocytidine exclusively degranulates the serous cells. Noradrenaline stimulates both serous and mucous cells and gives rise to vast cytoplasmic changes. Pilocarpine only shows effect on the mucous cells with formation of intracytoplasmic vacuoles. The effects reported are discussed with regard to experiments on salivary gland radiosensitivity.