Reutilization of 5- 125 I-Iodo-2′-Deoxyuridine and 3 H-Thymidine in Regenerating Liver of Mice

Abstract

Summary

Parallel studies of ³H-TdR and ¹²⁵I-UdR incorporation into regenerating liver following repeated injection into female Swiss albino mice yielded the following results: (i) both ³H-TdR and ¹²⁵I-UdR are reutilized, although ³H-TdR to a considerably greater extent; (ii) in addition to local reutilization, the data are explained by labeled precursors entering the regenerating liver from the intestine via the portal circulation. Precursor supply from immigrated leukocytes also occurs; and (iii) since a bypass of the thymidine kinase salvage pathway is unlikely, the incorporation of tracer into the regenerating liver must occur from the nucleoside level.