Radiosensitivity of C. parvum-stimulated spleen to acute 60Co and low dose rate 137Cs and 252Cf irradiation.
Stimulation of spleen growth by injection of C. parvum led to rapid organ enlargement, and acute 60Co or low dose rate (LDR) 137Cs or 252Cf irradiation reduced the maximum enlargement achieved. Irradiations were carried out 3 days after CP injection. Sigmoid dose-response curves were observed for the fraction of maximum enlargement achieved after acute 60Co. After low dose rate 137Cs or 252Cf irradiation, exponential dose-response curves of very different slope were observed. Acute and LDR gamma-radiation produced reduced effects in the stimulated and proliferating spleen compared to LDR 252Cf neutron/gamma-irradiation which had relative biological effectiveness = 4.0 versus low dose rate 137Cs.
D000818:Animals; D002142:Californium; D002588:Cesium Radioisotopes; D003037:Cobalt Radioisotopes; D004307:Dose-Response Relationship, Radiation; D005720:Gamma Rays; D051379:Mice; D008810:Mice, Inbred C57BL; D009502:Neutrons; D011425:Propionibacterium acnes; D012062:Relative Biological Effectiveness; D013154:Spleen / Q000276:immunology / Q000528:radiation effects*; D013163:Splenomegaly / Q000209:etiology; D014916:Whole-Body Irradiation
D002588:Cesium Radioisotopes; D003037:Cobalt Radioisotopes; D002142:Californium