[Effect of single dose irradiation to parotid gland on the structured and function changes of bilateral parotid glands in miniature pig].
OBJECTIVE
To evaluate the effects of a solitary megadose protocol of ionizing radiation (IR) to parotid gland on the structured and function changes of bilateral parotid glands in miniature pig.


METHODS
Fourteen minipigs were subjected to either 15 or 20 Gy to one parotid gland with a linear accelerator, while another four minipigs served as non-IR controls. Salivary flow rates and salivary chemistries were measured pre-IR, and 4 and 16 weeks post-IR. A quantitative assessment of gland weight and acinar area, and detailed serum chemistry and hematological analyses, were also performed.


RESULTS
Parotid gland weights were significantly decreased in the 15 and 20 Gy groups at 4 and 16 weeks post-IR. The acinar cell area in glands of both IR groups was significantly reduced. Parotid flow rates decreased by 60% with 15 Gy at 16 weeks post-IR. In the 20 Gy group, salivary flow rates were reduced by 80% at 16 weeks post-IR. Additionally, parotid flow rates significantly reduced in contralateral glands with 20 Gy at 16 weeks, while structure and weight did not changes in parotid glands.


CONCLUSIONS
Structural changes in salivary gland parenchyma occurred relatively early after IR, while the alterations in salivary output were relatively delayed. Further, reductions in salivary flow were not proportional to acinar cell area loss. There isn't a significant structured change of contralateral glands, but significant reduction of parotid flow rate at this time.
Salivary Gland Disease Center and Molecular Laboratory for Gene Therapy, Faculty of Stomatology, Capital University of Medical Sciences, Beijing 100050, China.
Zhao-Chen
ZC
Shan
Jun
J
Li
Guang-Fei
GF
Ou
Xiao-Yong
XY
Liu
Chun-Mei
CM
Zhang
Song-Ling
SL
Wang
D000818:Animals; D010306:Parotid Gland / Q000528:radiation effects*; D013552:Swine; D013556:Swine, Miniature