Oncology: Radiation Sensitivity
Discovery of genes that when manipulated afford radioprotection could possibly lead to development of drugs to protect health and life in the event of, for example, a nuclear accident or attack. Conversely, genes that when manipulated sensitize the cancer cell to radiation induced death could be targeted with a "radiation sensitizer" drug to improve radiotherapy for cancer. Only male animals are tested.
Approximately 50 µL of blood is collected from the saphenous vein immediately prior to irradiation (collection time 1) and the differential WBC count is determined using a HemaVet 850 hematology system. The mouse is then irradiated for ~2 minutes (3 Gy) using a GAMMATOR G-50-B GAMMA IRRADIATOR 137Cs source. Blood collection and determination of peripheral WBC counts is then performed at 3 (collection time 2), 10 (collection time 3), 17 (collection time 4), and 24 days post-irradiation (collection time 5). Data is reported as WBCs (or specific cell type) per microliter or as mean percentage of pre-irradiation.
Displayed below is a sample graph of how radiation-induced changes in white blood cell counts are presented. In comprehensive phenotypic data packages graphs are interactive. Raw or calculated data and statistics can be seen by clicking on points in the graph. Figure illustrates percentage of pre-irradiation white blood cell counts (left) and number of white blood cells per microliter (right) of male wild type littermates (green circle) and homozygous (red diamond mice plotted against long-term historical values (+/- 2 standard deviations) for wild type animals (green shading). Long-term historical values are derived from data collected on more than 10,000 wild type mice.