Tritiated thymidine effects on DNA, RNA, and protein synthetic rates in synchronized L-cells

✍ Scribed by Margarida O. Krause

• Book ID: 102878782
• Publisher: John Wiley and Sons
• Year: 1967
• Tongue: English
• Weight: 811 KB
• Volume: 70
• Category: Article
• ISSN: 0021-9541
• DOI: 10.1002/jcp.1040700203

✦ Synopsis

Exponentially growing L-cells were synchronized by the double thymidine-block method and exposed to high specific activities of tritiated thymidine. DNA, RNA, and protein synthetic rates were measured through one cell cycle with 1-hour pulses of the appropriate Ci4-labelled precursors. Equivalent doses of tritiated water were substituted for tritiated thymidine in some experiments. Total amounts of DNA and histones per nucleus were determined photometrically in FeuIgen and fast-green stained cells.

It was observed that incorporated tritiated thymidine has a n effect distinct from that of tritiated water and that it enhances the incorporation of the precursors at spec& stages of the cell cycle, to a degree roughly proportional to the dose. Photometric data indicated a n increase in DNA net synthesis and a metabolic instability of histones in the H3-thymidine-treated cells, resulting in higher DNA:histone ratios.