Biochemical indicators of whole-body gamma-radiation effects in the pig

PURPOSE: Validation of the pig as an experimental animal model for dose assessment after ionizing irradiation. MATERIALS AND METHODS: The evolution of haematological and biochemical parameters was followed for up to 7 days after irradiation in pigs exposed to whole-body 60Co gamma-radiation at doses between O and 6 Gy. RESULTS: Some biochemical indicators showed significant variations: amylase, LDH, alkaline and acid phosphatases, ALT and iron. None of the studied parameters alone presents a reliable dose-effect relationship; however, there was evidence that the combination of lymphocyte and neutrophil counts and the determination of LDH, ALT, AST and urea levels allowed some dose determination, independent of time, if blood samples were taken within 7 days post-irradiation. CONCLUSION: The results confirm the main problems of biochemical dosimetry. However, the pig model could represent a useful alternative to the non-human primate in radiobiology research, especially in the case of partial-body exposure. A multiparametric approach to dose assessment seems to be possible in the pig model. Confirmation should be carried out using blood samples from patients undergoing radiotherapy treatment.