INTESTINAL RADIOPROTECTION BY VITAMIN-E (ALPHA-TOCOPHEROL)

Objectives The major objective of this study was to test Vitamin E as a potential radioprotectant for the small bowel of the rat. Summary Ba ckground Data Vitamin E has previously been shown to provide radioprot ection in animal models: increased survival after whole-body irradiati on, diminished absorptive malfunction, and modest diminution in postir radiation hemolysis. The lumenal route for intestinal radioprotection has not been tested. Methods Rat mid-small bowel was surgically exteri orized and segmented by ties into compartments, each of which was fill ed with a test solution 30 minutes before 1100 cGy of x-irradiation wa s administered. After the rats were killed 5 days later, the Various s egments were evaluated for surviving crypts, mucosal height, and goble t cell preservation. Lumenal agents included alpha-tocopherol phosphat e and alpha-tocopherol acetate. In a separate study, dietary supplemen ts of alpha-tocopherol were given for 10 days before irradiation, and the same irradiation sequence was carried out. Results Small bowel cry pt cell numbers, mucosal height, and goblet cell numbers were signific antly protected from radiation effects by dietary alpha tocopherol pre treatment and by lumenal application of the vitamin. Conclusions These studies indicate that vitamin E can serve as a partial protectant aga inst acute irradiation enteritis, whether given as chronic oral system ic pretreatment or as a brief topical application.