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Synthesis and turnover of DNA in hepatocytes of neonatal rats
Author(s) -
ViolaMagni M. P.
Publication year - 1972
Publication title -
journal of microscopy
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.569
H-Index - 111
eISSN - 1365-2818
pISSN - 0022-2720
DOI - 10.1111/j.1365-2818.1972.tb04656.x
Subject(s) - dna synthesis , dna , nucleus , mitosis , feulgen stain , thymidine , specific activity , chemistry , hepatocyte , cell cycle , cell nucleus , cell , microbiology and biotechnology , biology , andrology , biochemistry , enzyme , medicine , in vitro
SUMMARY The incorporation of 3 H‐thymidine has been studied in the hepatocytes nuclei of rats during the first 3 days of life. The synthesis of DNA which occurs in 18% of nuclei after a single injection of the labelled precursors 2 h after birth, cannot be considered as premitotic since:(i) The hepatic cell number is constant during the first 3 days of life. (ii) The mitotic index is less than 0·1%, 20 times lower than that expected on the basis of the labelling index and of the length of cellular cycle. (iii) The percentage of labelled nuclei does not increase in the following 3 days. (iv) The average number of grains per nucleus is unchanged for 18 h after the injection, a period longer than an entire cellular cycle (13 h).This synthesis is better explained as due to an increase of DNA content per nucleus, previously described, in the hepatocytes during the first 3 days of life. After 20 h of life (18 h after label injection) a decrease of label of about 30% takes place without variation of DNA‐Feulgen dye content per nucleus. It is concluded that synthesis and turnover of DNA are present in the hepatocytes nuclei and that these processes are probably related to the functional maturation of the cells.