Effect of phenylhydrazine induced hemolytic anemia on nuclear RNA polymerase activity of the mouse spleen

The DNA dependent RNA polymerase of nuclei from lymphoid rich and erythroid rich mouse spleens was compared in regard to requirements and conditions of the reactions. The inhibition by either actinomycin D or pancreatic DNase indicated that a DNA template was required for the observed reactions. Following the induction of a hemolytic anemia by the administration of phenylhydrazine, there was a tenfold increase in the nuclear polymerase activity per milligram nuclear DNA of the developing erythropoietic spleen when the assays were done at low ionic strength and more than a threefold increase at high ionic strength. The peak rise in polymerase activity precedes the maximal development of the erythropoietic spleen by 3 days.