Effect of ionizing radiation on rat parotid gland

Abstract

A common side effect of radiotherapy used in the treatment of oral cancer is the occurrence of structural and physiological alterations of the salivary glands due to exposure to ionizing radiation, as demonstrated by conditions such as decreased salivary flow. The present study evaluated ultrastructural alterations in the parotid glands of rats receiving a fractionated dose (1,500-cGy) of radiation emitted by a Cesium-137 source and rats that were not subjected to ionizing radiation. After sacrifice, the parotid glands were removed and examined by transmission electron microscopy. Damage such as cytoplasmic vacuolization, dilatation of the endoplasmic reticulum and destruction of mitochondria, as well as damage to the cellular membrane of acinar cells, were observed. These findings lead to the conclusion that ionizing radiation promotes alterations in the glandular parenchyma, and that these alterations are directly related to the dose level of absorbed radiation. Certain phenomena that appear in the cytoplasm and nuclear material indicate that ionizing radiation causes acinar cell death (apoptosis).

Melatonin's protective effect on the salivary gland against ionized radiation damage in rats

“…Table 1 The comparasion of severity of parotid histological damage among groups and number of mast cells In this study, radiation caused significant salivary gland injury as demonstrated by findings in the RT group, such as acinar shape defects, a partial loss of apical cytoplasmic material, considerable swelling and perinuclear vacuolization, and condensed-polymorphic nuclei in the acinar cells. These findings seem to be related to the induction of gland injury, consistent with other studies that utilized radiationinduced rat models (24)(25)(26). Moreover, increased malondialdehyde and TOS levels in the salivary glands were observed after 10 days of radiation administration.…”

Effect of low radiation dose on the expression and location of aquaporins in rat submandibular gland

“…Several studies have shown that radiation can cause glandular epithelial damage (Cherry and Glucksmann, 1959;Frank et al, 1965;Elzay et al, 1969;Savage et al, 1985;Ahlner et al, 1993;Friedrich et al, 2002;Nagler, 2003;Radfar and Sirois, 2003;Vier-Pelisser et al, 2005;Boraks et al, 2008), leading to salivary gland hypofunction and xerostomia. It seems plausible that functional loss occurs by structural changes imposed on these tissues by radiation and, therefore, alterations occur in the parenchyma and stroma of these glands.…”

Restoration of radiation therapy-induced salivary gland dysfunction in mice by post therapy IGF-1 administration

“…While significant levels of apoptosis immediately following radiation have been observed in mice [16,18-20], the presence of apoptosis in irradiated rats has been more variable [28-30]. Because acinar cells contribute a majority of saliva constituents including amylase and water, loss of these cells would impair normal saliva composition and lead to reduction in saliva flow.…”