Free and Membrane-bound Ribosomes and NADPH-Cytochrome C Reductase Activity in the Liver Cells of Protein-fed and Protein-deprived Rats

Abstract

Rats were starved for 7 days or fed a protein-free or a 25% casein diet for 7 or 14 days. Free and total ribosomes were prepared from the liver. A determination of the ratio of mg RNA of ribosomes to mg DNA of the total homogenate was made. In starved rats, RNA of free and membrane-bound ribosomes decreased to the same extent. In rats fed a protein-free diet only mg RNA of membrane-bound ribosomes decreased significantly, and after 14 days the ratio of RNA of free to total ribosomes was increased. NADPH-cytochrome c reductase activity in the liver decreased per mg DNA in protein deprivation but was unchanged per mg RNA of membrane-bound ribosomes.