Long-term salivary effects of single-dose head and neck irradiation in the rat

The effect of a single dose of X-irradiation (either 2.5, 5, 7.5, 10 or 15 Gy) to the head and neck region oil parotid and submandibular gland function in rats was evaluated for up to 1 year. No animal receiving 15 Gy survived the entire study. Animals receiving greater than or equal to 7.5 Gy showed significantly less increase in body weight over time. Average wet weights of both gland types were reduced with as little as 2.5 Gy. Pilocarpine-stimulated parotid salivary flow was diminished significantly at 12 months for each radiation;dose group. Significant salivary flow reductions from submandibular glands were seen at greater than or equal to 7.5 Gy at this same time-point. These results show that a single radiation exposure of as low as 2.5 Gy to the head and neck region of rats can cause significant long-term alterations in salivary gland function. (C) 1998 Elsevier Science Ltd. All rights reserved.