Elevated Plasma Deoxycytidine Levels in Rats: A Biologic Dosimeter of X Radiation

摘要

Deoxycytidine (CdR) was identified as the major deoxynucleoside present in normal rat blood plasma, at basal levels ranging from 5.2 - 7.8 micrograms/cc. The separation procedure involved charcoal absorption and paper chromatography (butanol-H2O-NH3 system), and quantitative estimation was carried by the isotope dilute method, employing CdR-2-C14. Significant increases in plasma CdR levels (25-50% over normal) were observed 2 or 3 hours following exposures to 25 R, 33 R, and 50 R of whole-body X radiation. A curvilinear dose-response relationship was evident in the range of 50 R to 200 R, while the response was essentially flat between 200 R and 600 R. The significance of these findings as a basis for a biologic dosimeter for radiation exposure, is discussed. (Author)