Changes in the content of nucleic acids in organs of young rats during arrested growth.

Abstract

Summary. Normal growing rats were fed a diet deficient in protein for varying periods up to four months. Data were collected on changes in organ weight, total nitrogen, DNA and RKA content per organ. Organs studied were liver, heart, kidney, brain, lung, spleen arid thymus. The constancy of the DNA content during protein starvation was confirmed. In the livers of protein‐starved animals, while DNA per gram of tissue remained constant, histologically cell size diminished and the number of nuclei tripled. It is suggested that reduction of polyploid nuclei to the diploid form might partly account for this finding. Alterations in RNA content paralleled those of DNA and seem to establish that in young rats RNA is almost as “stable” metabolically as DNA.