Liver nuclear phospholipids of rats with varying thyroid status

: Thin-layer chromatography was used for fractionation of rat liver nuclear phospholipids after in vivo administration of 14C-sodium acetate. The administration of T3 to thyroidectomized rats caused a sharp increase in the incorporation of the label in all phospholipids of the nuclear fraction. The action of sphingomyelin and sphingomyelase on RNA-polymerase of nuclei isolated from the liver of thyroidectomized rats was tested. Sphingomyelin was shown to cause stimulation of RNA nuclear synthesis; parallel incubation with sphingomyelinase eliminated a stimulating effect of this phospholipid.