[Kinetics of deoxyribonuclease I action on the DNA of different white rat tissues].

Studies have been made on the kinetics of the effect of DNAse I on nuclear DNA from the brain cortex, liver, spleen and kidney of albino rats. In all the nuclei studied, two DNA sites revealed which especially differ in the rate of their splitting. The share of rapidly splitted DNA amounts in the nuclei of the kidney and brain cortex up to 30%, in those of the liver and spleen -- about 25%. These findings are discussed in relation to the data available on the share of transcribed chromatin in the same tissues obtained by hybridization with nuclear RNA. For the brain and liver this method yields the same values, whereas for the spleen and kidney this test yields significantly lower values, i. e. about 10%.