Analysis of the metabolic characteristics in rat plasma after total body irradiation / 中华放射医学与防护杂志

ABSTRACT

Objective:To investigate the metabolite changes in rat plasma after total body irradiation (TBI) and to explore dose classification based on radiation sensitive metabolites.Methods:The differential metabolites induced by radiation were screened and verified by metabolomics. In the discovery stage, 50 SD rats were irradiated with 0, 1, 2, 3, 5 and 8 Gy of 60Co γ-rays. In the verification stage, 25 rats were irradiated with 0, 0.5, 2.5, 4 and 6 Gy. Peripheral blood samples were collected 4 h after irradiation, and plasma was separated. Radiation-induced differential metabolites were identified and their concentrations were determined. Receiver operating characteristic (ROC) curve of the differential metabolites was used to classify dose range. Results:In the discovery stage, 8 radiation-induced differential metabolites in rat plasma were identified and four of them (cytosine, L-hexylcarnitine, Linoelaidylcarnitine and L-palmitylcarnitine) were upregulated, which was confirmed in the verification stage. The area under the curve (AUC) for the specific dose was >0.75. After combining these four metabolites, the AUC value to classify the radiation dose of 0 Gy versus >0 Gy, <2 Gy versus ≥2 Gy, <5 Gy versus ≥5 Gy were 0.96, 1 and 0.94, respectively.Conclusions:The metabolites in rat plasma changed significantly at 4 h after TBI, where 8 differential metabolites were identified. Cytosine, L-hexylcarnitine, linoelaidylcarnitine and L-palmiylcarnitine were stably over-expressed in the plasma after irradiation. The combination of these four compounds had high classification accuracy and thus may applicable as radiation sensitive biomarkers for dose classification.