Simulation of rabbit model to study the effect of ¹³¹Iodine and radioprotectant on salivary gland ultrastructure

The damaging effect of ¹³¹Iodine therapeutic radiation exposure and effect of radioprotectant administration on parotid gland was studied at ultrastructural level in New Zealand White rabbits. Animal model of NZW rabbits (n=11) was developed to mimic the ¹³¹Iodine (1GBq dose) therapy conditions in human population. It consisted of Control, exposed to ¹³¹I and pre-supplemented with O. sanctum and Amifostine animal groups. After 6 months of ¹³¹I exposure parotid gland was collected for histopathology and electron microscopy. Histological evaluation of parotid glands, in ¹³¹Iodine exposed group revealed random degeneration, lipomatosis, and necrosis of the serous acinar cells. Ultrastructural changes revealed, degeneration and destructive changes in mitochondria, rough endoplasmic reticulum, nucleus and secretory granules. These changes were significantly increased in ¹³¹Iodine group as compared to the radioprotectant pre-supplemented and control group. Electron microscopic observations of parotid gland support the histopathological observations. These findings lead to the conclusion that ionizing radiation have exhibited greater damaging effect on parotid gland in only ¹³¹I exposed animals as compared to control and radioprotectant pre-supplemented animals.