title: The effect of embryonal thymic calf extracts on neonatally thymectomized mice and on mice lethally irradiated with gamma rays.
abstract: The effect of embryonal thymic calf extracts (ETCE) on mice thymectomized at birth was investigated. ETCE was found to induce an increase in leukopenia and a decrease in the level of serum gamma globulins; it also reduced survival time in mice. The effect of ETCE on lethally irradiated mice was also examined. Only long-term administration of ETCE prior to gamma irradiation at 750 rad prolonged the survival time of mice (40% permanent survival) as compared with irradiated controls; the leukocytes from mice retained mitotic capability. Neither long-term treatment with ETCE  prior to irradiation at 1000 rad, nor short-term administration prior to 750 rad affected survival time. ETCE administered after irradiation of mice with 750 rad caused a rapid decrease in blood leukocytes and a significantly lowered survival time.
mesh_terms: D000818:Animals; D000831:Animals, Newborn / Q000502:physiology*; D002417:Cattle; D005720:Gamma Rays; D007958:Leukocyte Count; D007962:Leukocytes / Q000528:radiation effects*; D008297:Male; D051379:Mice; D013934:Thymectomy; D013950:Thymus Gland / Q000196:embryology* / Q000502:physiology; D014020:Tissue Extracts / Q000494:pharmacology; D014916:Whole-Body Irradiation
chemical_list: D014020:Tissue Extracts