The relation between cell division rate and 3HTdR incorporation in organ culture

✍ Scribed by John D. Simnett; Jean M. Fisher

• Publisher: John Wiley and Sons
• Year: 1973
• Tongue: English
• Weight: 742 KB
• Volume: 81
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040810206

✦ Synopsis

Abstract

Rates of incorporation of labelled thymidine (RIT), radioautographic labelling index for DNA synthesis (LI) and mitotic incidence following colcemid metaphase arrest (MI) were measured in organ cultures of newborn and adult rat lung. In adult cultures these three parameters correlated well, being low after explantation and reaching a maximum after two to three days. In newborn cultures RIT fell several fold over the first 24 hours after explantation and, in this respect, did not correlate with LI and MI. The changes in RIT over the first 24 hours appear to be due to changes in the degree of competition between endogenous TdR and exogenous labelled TdR, probably caused by leakage of the intracellular thymidine pool following explantation. The report emphasizes the need to check RIT data against radioautographic evidence before accepting it as an index of DNA synthesis.