PURPOSE: The purpose of our study is to examine phospho-ATF-2(Thr-69/71) (phospho-activating transcription factor-2, p-ATF-2), phospho-CREB(Ser-133) (phospho-cAMP response binding element protein, p-CREB), and phospho-c-Myc(Thr-58/Ser-62) (phosho-myelocytomatosis protooncogene, p-c-Myc) expression in irradiated rat colon transversum. MATERIALS AND METHODS: Male Wistar rats were randomly divided to 28 groups and irradiated with whole-body gamma-radiation of 0, 0.25, 0.5, 0.75, 1, 2, 3, 4, 5, 6, 7, 8, 9, and 10 Gy. Samples were taken 4 and 24 hours after the irradiation, immunohistochemically stained. P-ATF-2, p-CREB, and p-c-Myc expression was measured. RESULTS: We measured increased cytoplasmatic p-ATF-2 expression 4 hours after irradiation by 0.25 - 1, 10 Gy and 24 hours after irradiation by 0.5 - 1, 10 Gy. Increased cytoplasmatic p-CREB expression was found 4 hours after irradiation by 0.25 - 1, 9, 10 Gy and 24 hours after irradiation by 0.25 - 1, 4, 10 Gy. Increased p-c-Myc cytoplasmatic expression was found 4 hours after irradiation by 0.25, 0.75, 4, 5 Gy and 24 hours after irradiation by 0.75, 1, 10 Gy. Nuclear p-ATF-2, p-CREB, and p-c-Myc expressions were similar to their cytoplasmatic expressions. CONCLUSION: The detection of p-ATF-2 and p-CREB might be considered as a perspective biodosimetric tool for irradiated enterocytes in vivo. The use of p-c-Myc appears to be controversial due to the ambivalent expression values.

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