title: In vitro and in vivo production of CFU-S-stimulating activities after 5-Gy total body irradiation.
abstract: In vitro and in vivo production of CFU-S-stimulating activities have been described after 5-Gy irradiation of mice using a diffusion chamber-incubation technique. The experimental results showed that bone marrow obtained 15 min after 5 Gy total body irradiation did not present detectable CFU-S stimulating activity, but was able to produce such activity in vitro within 20 h. Once the activity had been produced, 2.5 h was enough to stimulate the proliferation of CFU-S. When CFU-S were incubated for 20 h in the peritoneal cavities of mice that had been irradiated with 5 Gy immediately prior to the insertion of the chambers, or five days earlier, a marked stimulation of CFU-S turnover was observed, demonstrating the in vivo production of some humoral activity capable of stimulating CFU-S.
mesh_terms: D000818:Animals; D001853:Bone Marrow / Q000502:physiology / Q000528:radiation effects*; D002453:Cell Cycle; D003114:Colony-Forming Units Assay; D004058:Diffusion; D006410:Hematopoiesis; D066298:In Vitro Techniques; D051379:Mice; D013154:Spleen / Q000166:cytology; D013997:Time Factors; D014965:X-Rays