Nucleic acid metabolism in regenerating rat liver. I. The rate of deoxyribonucleic acid synthesis in vivo.

作者：Liselotte I. Hecht, Van R. Potter · 发表于：PubMed · 年份：1956 · 被引用次数：158 · 研究领域：Liver physiology and pathology

Summary 1.A single injection of orotic acid-6-C 14 was administered to partially hepatectomized rats 24 hours after the operation. An average of 40 per cent of the dose of radioactivity was excreted in the urine during the first 4 hours, and an average of 20 per cent of the dose appeared in the respiratory CO 2 within 20 hours. 2.The liver contained 35–45 per cent of the dose of C 14 30 minutes after the injection. Initially the labeled acid-soluble intermediates were incorporated into nuclear RNA at a rate greatly exceeding the appearance of C 14 in the cytoplasmic RNA. Twelve hours after the injection, the specific activities of the nuclear and cytoplasmic RNA were nearly the same, and a parallel decrease in the specific activity of the two RNA fractions was observed thereafter. Sixty-four and 100 days after injection the RNA fractions contained very low amounts of C 14 . 3.The isotope content of the DNA continued to increase during the first 24-hour period, and throughout the subsequent 100-day period the isotope level of the total liver DNA remained about the same. 4.A time curve of the rate of DNA synthesis during the early period of liver regeneration has been described. No DNA synthesis occurred during the first 18-hour period postoperatively, a maximum rate of DNA synthesis was observed 24–30 hours after the operation, and incorporation of C 14 into DNA continued extensively for the subsequent 2-day period.