The effects of zinc in the gastrointestinal system as a radioprotective agent

Background: radioiodine i131 therapy (rai) is an efficient method to decrease thefunctioning of very active thyroid tissues and to ablate the remnant thyroidal tissueafter surgery and its metastases in differentiated thyroid carcinomas. severalcytoprotective, anti-oxidant or radioprotective mediators have been used in trialsfor rai-induced damage in other organ systems. the hypothesis of this study wasthat zinc would ameliorate rai-induced histopathological parameters in the ratgastrointestinal system. materials and methods: a total of 30 female wistaralbino rats were separated into 3 groups of 10. first group received only 0.003 mci/g of i131, second group received 0.003 mci/g of i131 and 0.01 mg/g of zinc and thecontrol group (sham group) were given neither i131 nor zinc. zinc was started viagastric gavage two days before i131 administration and continued for five daysafter rai. at 24 hours after the last dosage of zinc, all the animals were sacrificedand the gastrointestinal tissues, including stomach, duodenum, ileum and colonwere removed for histopathological examination. results: all thehistopathological parameters were diminished in the i131-zinc groupcompared to the i131 group. the histopathological differences werestatistically significant in respect of inflammation and fibrosis between thei131-zinc group and the i131 group in all the evaluated gastrointestinal organs(p< 0.05). conclusion: the co-administration of zinc was observed to significantlyprevent rai-induced histopathological alterations in rats.