Ionizing irradiation and the salivary gland sequelae

Abstract

• Salivary gland damage due to radiotherapy, leading to xerostomia and causing a great of suffering to patients, is a phenomenon known since the beginning of this century. The mechanism responsible for it has not been elucidated and no adequate treatment for patients is available. According to the mechanism suggested for the parotid irradiation-induced specific damage, the injurious agents resulting in delayed serous cell death, leading to specific parotid radiosensitivity, are transition, highly redox-active metal ions, such as Fe and Cu, associated with secretion granules. These ions enhance the lethal effect that irradiation has on DNA, resulting in a reproductive delayed cell death. The immediate effects of metal-mediated enhancement of irradiation damage in cells may occur but does not seem to play a major role in the underlying mechanism. Indeed, in a series of recent experi ments, it was succeeded in positively correlating an extended time point (two months) protection of parotid function with preirradiation degranulation and redox active metal ion mobilization out of the gland into the secreted saliva prior to irradiation. In contrast, a negative correlation in the submandihular gland, with no protection, no degranulation, no metal ion mobilization and no redox activity was demonstrated. The ability to protect the parotid function at two months with Zn

Radiation therapy and serum salivary amylase in head and neck cancer

“…Although irradiation-induced damage in salivary gland was first described in 1911, its mechanism is still a de- bate [ 10 ]. Salivary glands tissue is largely differentiated and metabolically active with a low mitotic rate and no expected future mitoses [ 11 ]. Thus, based on Bergonie and Tribondeau radiosensitivity law, salivary glands are presumably radioresistant.…”

“…During the acute phase of radiation damage, within few hours after dose up to 4 Gy, the amylase secretion is quickly affected, with a 10 to 80 fold increase of the serum value. This phenomenon reaches its peak within 12–36 hours and it seems to be a direct consequence of acinar cells impairment [ 11 ]. Later on the amylase production deteriorates, due to newly formed acinar cells that are unable to work properly.…”

Saliva: a pontential tool in Dentistry.

“…La α-amilasa salival (αAS) es la enzima más abundante en la saliva, producida principalmente por los acinos serosos de la glándula parótida pero también por las glándulas sublinguales, submaxilar y las menores. Es un buen indicador de la función de las glándulas salivales y de la salud general de un individuo 16 . El principal sustrato de la αAS son los almidones y los productos finales de la digestión son glucosa, maltosa y dextrinas.…”

Salivary Amylase as a Marker of Salivary Gland Function in Patients Undergoing Radiotherapy for Oral Cancer

“…Therefore, salivary amylase is a good indicator of the function of salivary glands, and hence, of the general health of an individual . At best, the results of this study can use the quantitation of salivary amylase as a surrogate marker of damage to salivary gland function due to radiotherapy.…”