Incorporation of Tritiated Thymidine into DNA after Oral Administration. ∗

Abstract

Summary

1. H³TDR was administered via stomach tube to rats, mice, and guinea pigs. 2. Some ingested H³TDR was absorbed and labeled proliferating cells of gastrointestinal mucosa as early as 2 hours after ingestion in guinea pigs. 3. Labeling of diverse tissues including proliferative cells of the testes was seen in rats and mice 7I/2 hours after ingestion. 4. Some of the H³TDR was degraded to tritiated water while small amounts of non-volatile H³ activity were excreted in the urine. 5. The significance of absorption of H³TDR through intestinal mucosa is discussed as related to potential hazard.