Dose-Dependent Effects of H 3 TDR as a DNA Label on the Replication of Liver Cells in the Growing Rat

Abstract

The effects of increasing amounts of H3TDR (1, 2 and 10 [mu]c/g) as a DNA label have been studied in vivo in the liver cells of the 3 week-old male Wistar rat. At 1 [mu]c/g the liver cells pass through a regular spaced replication cycle. With the higher labeling doses (1) cells labeled late in DNA synthesis are delayed in DNA synthesis and G2, (2) regular rhythmic replication is disrupted, and passage through the cycle is delayed, (3) the number of labeled and unlabeled cells in mitosis decreases, (4) the dominant ploidy class of the replicating cohort is diploid (5) the effects are dose-dependent and due to radiation and (6) the metabolic phenomena concerned with cell replication are more sensitive to radiation than are those concerned with cell survival.