Abstract
The effect of thioacetamide on dividing cells of regenerating rat liver has been studied. Rats were given daily subcutaneous injections of thioacetamide as a 1 per cent solution at a dosage of 5 mg./100 gm. body weight for 7 to 10 days, subjected to partial hepatectomy, and sacrificed 28 to 31 hours later. Thioacetamide treatment results in striking increases in the nuclear ribonucleoproteins of the liver cell without affecting the mitotic rate during regeneration (14). During mitosis, RNA-containing particles were seen within the spindle and coating the contracted chromosomes from prophase through metaphase or early anaphase. At telophase, prior to the reconstruction of the nuclear membrane, fine RNA-containing granules appeared within the compact chromosomal groups. These coalesced to form nucleoli corresponding in number to the number of nucleolar organizer regions. The nuclei and nucleoli showed a rapid increase in size during the reconstruction period when compared with corresponding figures of the control liver samples. Electron micrographs of interphase nucleoli indicated a similar basic granular structure in both drug-treated and control animals. The question is raised as to whether the increased nucleolar material merely made visible some of the nucleolar-chromosomal associations that normally occur in mitosis, or whether thioacetamide directly affects the synthetic activity of the contracted mitotic chromosomes.
Full Text
The Full Text of this article is available as a PDF (714.7 KB).
Selected References
These references are in PubMed. This may not be the complete list of references from this article.
- BERNHARD W., BAUER A., GROPP A., HAGUENAU F., OBERLING C. L'ultrastructure du nucléole de cellules normales et cancéreuses; étude au microscope électronique. Exp Cell Res. 1955 Aug;9(1):88–100. doi: 10.1016/0014-4827(55)90162-2. [DOI] [PubMed] [Google Scholar]
- CAULFIELD J. B. Effects of varying the vehicle for OsO4 in tissue fixation. J Biophys Biochem Cytol. 1957 Sep 25;3(5):827–830. doi: 10.1083/jcb.3.5.827. [DOI] [PMC free article] [PubMed] [Google Scholar]
- HORSTMANN E., KNOOP A. Zur Struktur des Nucleolus und des Kernes. Z Zellforsch Mikrosk Anat. 1957;46(1):100–107. [PubMed] [Google Scholar]
- KAUFMANN B. P., McDONALD M., GAY H. Enzymatic degradation of ribonucleoproteins of chromosomes, nucleoli and cytoplasm. Nature. 1948 Nov 20;162(4125):814–814. doi: 10.1038/162814a0. [DOI] [PubMed] [Google Scholar]
- KLEINFELD R. G. Early changes in rat liver and kidney cells induced by thioacetamide. Cancer Res. 1957 Nov;17(10):954–962. [PubMed] [Google Scholar]
- KLEINFELD R. G., VON HAAM E. The effect of thioacetamide on rat liver regeneration. I. Cytological studies. Cancer Res. 1959 Aug;19:769–778. [PubMed] [Google Scholar]
- LAFONTAINE J. G. Structure and mode of formation of the nucleolus in meristematic cells of Vicia faba and Allium cepa. J Biophys Biochem Cytol. 1958 Nov 25;4(6):777–784. doi: 10.1083/jcb.4.6.777. [DOI] [PMC free article] [PubMed] [Google Scholar]
- OHNO S., KAPLAN W. D., KINOSITA R. The centromeric and nucleolus-associated heterochromatin of Rattus norvegicus. Exp Cell Res. 1959 Feb;16(2):348–357. doi: 10.1016/0014-4827(59)90263-0. [DOI] [PubMed] [Google Scholar]
- PORTER K. R. Electron microscopy of basophilic components of cytoplasm. J Histochem Cytochem. 1954 Sep;2(5):346–375. doi: 10.1177/2.5.346. [DOI] [PubMed] [Google Scholar]
- RIS H., KLEINFELD R. Cytochemical studies on the chromatin elimination of Solenobia (lepidopteria). Chromosoma. 1952;5(4):363–371. [PubMed] [Google Scholar]
- STOWELL R. E. Nucleic acids and cytologic changes in regenerating rat liver. Arch Pathol (Chic) 1948 Aug;46(2):164–178. [PubMed] [Google Scholar]
- SWIFT H. Nucleoproteins in the mitotic cycle. Tex Rep Biol Med. 1953;11(4):755–774. [PubMed] [Google Scholar]
- WOODS P. S., TAYLOR J. H. Studies of ribonucleic acid metabolism with tritium-labeled cytidine. Lab Invest. 1959 Jan-Feb;8(1):309–318. [PubMed] [Google Scholar]
- YASUZUMI G., SAWADA T., SUGIHARA R., KIRIYAMA M., SUGIOKA M. Electron microscope researches on the ultrastructure of nucleoli in animal tissues. Z Zellforsch Mikrosk Anat. 1958;48(1):10–23. doi: 10.1007/BF00496710. [DOI] [PubMed] [Google Scholar]