(Iso) Prostaglandins in saliva indicate oxidation injury after radioiodine therapy.

UNLABELLED As salivary glands concentrate radioiodine the radiation injury associated with 131I-therapy may result in sialoadenitis and xerostoma leading to a lasting impaired quality of life. Recently we reported about prostaglandin concentration changes as biochemical markers for radiation injury. Isoprostanes, a new family of prostaglandin-like compounds, have been demonstrated to be reliable markers for oxidation injury in vivo. PATIENTS AND METHODS In this study we examined the levels of 8-epi-PGF2alpha, the major member of the isoprostane family in 24 patients undergoing 1311 treatment in different doses for hyperthyroidism and differentiated thyroid cancer. 6 healthy sex and age-matched volunteers were monitored in parallel. Saliva(iso)prostaglandins were determined before 131I treatment, as well as 1, 3, 7, 14, 21, and 28 days, and 2, 3, and 6 months after therapy. RESULTS 8-epi-PGF2alpha showed a significant 1311 dose-dependent temporary increase. The alterations were comparable in all investigated patients and significantly higher in cigarette smokers. TXB2 and 6-oxo-PGF, showed a dose-dependent increase too. TXB2 was higher in cigarette smokers and 6-oxo-PGF1alpha lower as compared to non-smokers. CONCLUSION These results clearly demonstrate a dose- and time-dependent tissue (TXB2, 6-oxo-PGF1alpha) and oxidation in-jury (8-epi-PGF2alpha) after 131I-therapy in the salivary glands.