OBJECTIVE: To evaluate the radioprotective effect of sodium selenite in the tissue repair process. MATERIALS AND METHODS: Male Wistar rats submitted to a surgical procedure to produce a wound in the dorsal region. These animals were then divided in four experimental groups: control, selenium, irradiated and selenium-irradiated. The selenium and selenium-irradiated groups received sodium selenite (2.0 mg/kg), 48 hours after surgery. The irradiated and selenium-irradiated groups received a single dose of 6 Gy, administered only in the borders of the wound. The animals were sacrificed after 4, 7, 13 and 21 days after surgery and morphological, histochemical and tissue birefringence analyses were performed. RESULTS: The structural and morphologic aspects, as well as the quality and maturation of the tissue assessed by the amount, arrangement and molecular orientation of the collagen fibers, showed a marked delay in wound healing caused by radiation and that sodium selenite has a radioprotective effect on the tissue repair process. CONCLUSION: The present study showed that sodium selenite is an efficient radioprotector given the fact that tissue repair process in the selenium-irradiated group was histologically similar to the control group.

Keywords: Ionizing radiation, Selenium, Free radicals