Alpha-Adrenergic Stimulation and Radiosensitivity on the Rat Submaxillary Gland

Abstract

The submaxillary glands were exposed to fractionated irradiation comparable to 50 Gy in clinical practice and a single fraction of 50 Gy. Half the number of rats were given cyclocytidine, an alpha-adrenergic agonist which depletes the serous cell granules before irradiation was embarked upon. Our results show that irradiation causes a significant, irreversible destruction of serous cells. With cyclocytidine pretreatment, the radiodamage was diminished and this drug is suggested to act as a radioprotector, depleting secretory heavy metal granules, and thus preventing radiodamage in the submaxillary salivary glands.

Studies on the Regranulation of Salivary Gland Serous Cells

“…This increases the cell survival, as has previously been shown [1], One hour after injection of cyclocytidine there is an almost total depletion of secretory granules in the salivary gland serous cells. After 6 h a slight tendency of regranula tion is seen, with a few small granules apically located.…”

“…Dur ing this time the depletion of heavy-metal granules is a the most, and the morphological destruction would thus be diminished, as we have described in earlier publications [1,2], leading to a more preserved function of the salivary glands postirradiation therapy. In our experimental model we have found that one injection of cyclocytidine is sufficient to dcgranulate the serous cells.…”

“…In earlier publications we have demonstrated a dimin ished radiosensitivity in the rat salivary gland after deple tion of granules from the serous cells before irradiation [ 1,2], It is thus of interest to know more about the regranula tion process.…”

“…The effect is aadrenergically mediated [4][5][6][7][8], The serous cells are lo cated in the convoluted ducts, a-adrenergic drugs have been found to stimulate ductular serous cells [1,2,6],…”

A systematic review of salivary gland hypofunction and xerostomia induced by cancer therapies: management strategies and economic impact

“…At that time, the focus of research was on prevention and treatment of salivary glands from post-radiotherapy functional loss applying sialogogues, radioprotective agents, and/or saliva substitutes. Regarding sialogogues, the observation that drug-induced depletion of submandibular serous cell granules before irradiation resulted in a decreased radiosensitivity of rodent submandibular glands linked the radiosensitivity of these cells to the content of secretory granules [4][5][6]. In rodents, these granules contain high amounts of proteolytic enzymes and transition metals [4].…”