Effect of Protein Malnutrition on the DNA Content of Rat Liver

Abstract

The constancy of the DNA concentration in normal tissues has suggested the possibility of using this cellular component as a fixed point of reference to express the results of tissue analysis. In the field of nutrition, the constancy of this concentration in the liver has been questioned in those cases in which the rats have been fed protein-deficient diets. Some investigators who have studied the average DNA content of the isolated liver cell nucleus under conditions of protein deficiency, have not been able to show any significant increase. On the other hand, histochemical studies as well as DNA analysis of whole liver homogenates of the same type of animals have demonstrated a significant increase in the average DNA content of the nucleus and in the DNA concentration of the liver, respectively. In the present study, weanling and young adult rats were fed protein-deficient diets and the average DNA content of the isolated liver cell nuclei, as well as the DNA concentration of the whole liver homogenate, were studied. The results obtained strongly support previous observations that protein-deficient diets produce in the rat a significant increase in the average DNA content of the liver cell nucleus and in the DNA content of the liver.