Incorporation of 14C-thymidine into liver and brain DNA of protein-deficient rats.

The authors studied the effect of a protein-free diet on 14C-thymidine incorporation into rat liver DNA in vivo and found, after 2-3 weeks, a marked decrease in uptake of the radioactive base into the liver DNA, followed by a decrease in the proportion of DNA in liver cell homogenates. The total nuclear count/mg liver tissue displayed an increase during protein depletion, except for the 5th week, when a decrease was recorded. The incorporation of 14C thymidine into the brain DNA likewise displayed no great differences, although a significant drop was observed during the 2nd to 4th week of depletion.