RNA polymerisation capacity and permeability to ribonucleoside triphosphates of nuclei from livers of whole-body X-irradiated rats.

For 4--18 h following whole-body X-irradiation of rats, liver nuclei showed a progressive increase in the permeability to ribonucleoside triphosphates (as assessed in vitro using tritiated uridine triphosphate (UTP) and in the capacity to polymerise RNA in vitro (Mg++-containing and Mn++/(NH4)2SO4-containing assay systems).

[Retention of 241Am in the rat and the Syrian hamster]. / Retention von 241-Am bei Ratte und Syrischem Hamster

The retention of 241-Am during the first three months after injection as well as its microdistribution on the 2nd day were investigated in the rat and the Syrian hamster. Deposition, retention and microdistribution in the skeleton of both species are virtually identical; the same holds for kidneys, except for a higher initial deposition in the hamster. The microdistribution of 241-Am in kidneys and liver of both species is homogenous with a distinct accumulation in the cortical zone of the kidneys. A pronounced difference was observed with regard to the elimination of 241-Am from the liver: Most of the 241-Am is excreted by the rat liver with a half time of 7 days whereas this value is about 150 days for the Syrian hamster. The consequences of the species differences are discussed.