Some Effects of Continued Protein Deprivation, with and without Methionine Supplementation, on Intracellular Liver Components.

Abstract

The livers of rats maintained on a protein-free diet for 5 wks. contained more desoxypentosenucleic acid (DNA), an equal amt. of pentosenucleic acid (PNA), and less N than did the livers of control animals. In the case of the intracellular fractions of the liver, it was found that the nuclear fraction contained more DNA and PNA but an equal amt. of N; the mitochondrial fraction, less N but an equal amt. of PNA; the microsomatic fraction, less PNA and N; and the residual cytoplasmic fraction, considerably more PNA and less N that did the corresponding fraction of the livers from the control animals. The only apparent effect of the inclusion of DL-methionine in the protein-free diet at a level of 1% was an obviation of the increase in the PNA content of the residual cytoplasmic fraction. The changes encountered in the intracellular distribution of N and nucleic acids in the livers of protein-deficient animals fell into the same pattern as the changes in the livers of precancerous and cancerous animals.