Prostaglandins as biochemical markers of radiation injury to the salivary glands after iodine-131 therapy?

Abstract.

Because salivary glands, as well as thyroid tissue, are able to concentrate radioiodine, the treatment of thyroid diseases with iodine-131 may have secondary effects on salivary gland function which seriously impair the quality of life. Such effects include sialoadenitis and xerostomia. Salivary secretion is stimulated by prosta- glandins (PGs). In this study we evaluate whether ¹³¹I therapy influences the levels of PGs in saliva. Patients who had previously received ¹³¹I for treatment of hyperthyroidism or differentiated thyroid cancer and healthy volunteers were studied. Levels of PGs [6-oxo-PGF_1α, bicyclo-PGEm, thromboxane B₂ (TXB₂), PGF_2α] in unstimulated saliva were measured using enzyme immunoassay. Significantly lower levels of 6-oxo-PGF_1α, bicyclo-PGEm and PGF_2α and higher levels of TXB₂ were found in the group of patients in comparison with the controls. Differences between patients and controls were more pronounced in smokers. This study demonstrates that salivary gland uptake of ¹³¹I significantly affects PG levels in saliva.