[UMP synthase activity of rat tissue extracts in the bone marrow form of radiation sickness].

Whole-body gamma-irradiation of rats with a dose inducing bone marrow radiation syndrome caused phase organospecific changes in UMP-synthase activity. Disturbances of enzymic activity in the bone marrow and spleen well correlated with the dynamics of interphase and reproductive cell death. In brain extracts, UMP biosynthesis from orotic acid did not undergo essential changes.