The relationship between losses in labile liver cytoplasm and urinary nitrogen excretion

Abstract

Using hooded rats an attempt was made to correlate the excretion of "extra N " in the urine of rats during the first few days of a protein-free regimen with the N lost from the livers during the same period. At least 60% of the "extra N" can be accounted for by the N derived from the protein, nucleic acid and other nitrogenous substances of the liver. These findings make unlikely the older assumption of an unorganized "circulating" or "storage" protein which was supposed to be responsible for the appearance of the "extra N".