Radiation-induced decreases of serous cell immunoglobulin excretions in the rat submandibular gland.

The effect of radiation on the submandibular glands of the rat was studied with special reference to the immune reactivity of IgG and IgA. These immunoglobulins are localized in the serous cells and were influenced by irradiation. Radiation therapy markedly reduced the reactivity for both IgG and IgA. Immunocytochemistry showed a good correlation to the deteriorated morphology as revealed by light and electron microscopy. The local excretion of immunoglobulins in the submandibular gland can thus be affected by radiation and results in an increased risk for oral infections. Pretreatment of animals with the secretagogue cyclocytidine caused less pronounced damage in cellular ultrastructure and immunological findings, as observed by fluorescence microscopy.