DIFFERENCES IN REUTILIZATION OF THYMIDINE IN HEMOPOIETIC AND LYMPHOPOIETIC TISSUES OF THE NORMAL MOUSE
| Autor: | G. Friedrich, L. E. Feinendegen, E. P. Cronkite, H. J. Heiniger |
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| Rok vydání: | 1973 |
| Předmět: |
Spleen
Thymus Gland Biology Tritium Models Biological Iodine Radioisotopes Mice chemistry.chemical_compound Bone Marrow In vivo Intestine Small medicine Animals Mesentery Lymph node Nucleotide salvage DNA Cell Biology General Medicine Deoxyuridine Molecular biology In vitro Haematopoiesis medicine.anatomical_structure chemistry Organ Specificity Injections Intravenous Immunology Autoradiography Regression Analysis Female Spectrophotometry Ultraviolet Lymph Nodes Bone marrow Thymidine |
| Zdroj: | Cell Proliferation. 6:573-585 |
| ISSN: | 1365-2184 0960-7722 |
| DOI: | 10.1111/j.1365-2184.1973.tb01648.x |
| Popis: | Swiss Albino mice received a single i.v. injection of 3H-thymidine (TdR) or of 125I-deoxyuridine (IUdR). Bone marrow, thymus, spleen and mesenteric lymph node were examined for the efficiency of precursor incorporation into DNA, and for DNA renewal from day 1 to day 8. TdR is 5–8 times more efficiently incorporated by the different organs in vivo and in vitro than is IUdR. This indicates that the discrimination against IUdR occurs at the level of DNA synthesizing cells. A diminished DNA turnover rate measured with 3H-TdR in comparison with 125I-UdR is interpreted to indicate reutilization of TdR. TdR reutilization was observed in bone marrow and spleen from at least day 1 on, and in the thymus from day 3 on, following pulse labeling of DNA synthesizing cells. The degree of TdR reutilization appears higher in the thymus (67%) than the bone marrow (43%) and spleen (38%). The mesenteric lymph node indicates either no, or a very low efficiency of TdR reutilization. The data are also consistent with a reutilization equally efficient for TdR and IUdR. It is suggested that the TdR salvage pathway in hemopoietic tissues is largely localized to single organs which have immediate access to TdR made available by catabolism of DNA. The contribution of TdR from systemic reutilization to the organs studied falls within the limits of error of measurements. Moreover, the TdR salvage pathway especially in the lymph node may involve other DNA breakdown products than nucleosides. |
| Databáze: | OpenAIRE |
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