Early Effects of X-Irradiation on in Vitro DNA Synthesis in Mouse Spleen

1964 ◽  
Vol 22 (2) ◽  
pp. 288 ◽  
Author(s):  
N. Fausto ◽  
A. O. Smoot ◽  
J. L. Van Lancker
Keyword(s):  
Dna Synthesis ◽  
Mouse Spleen ◽  
X Irradiation ◽  
Early Effects

scholarly journals BIOLOGICAL EXPRESSIONS OF LYMPHOCYTE ACTIVATION

1973 ◽  
Vol 137 (3) ◽  
pp. 649-659 ◽  
Author(s):  
Robert R. Rich ◽  
Carl W. Pierce
Keyword(s):  
Cell Population ◽  
Concanavalin A ◽  
Lymphocyte Activation ◽  
Suppressor Cells ◽  
Mouse Spleen ◽  
Spleen Cells ◽  
Cell Responses ◽  
Helper Cells ◽  
X Irradiation

A population of thymus-derived lymphocytes has been identified that, upon activation by the nonspecific plant mitogen concanavalin A, suppresses the development of plaque-forming cell responses in fresh or 48-h antigen-stimulated cultures of mouse spleen cells. Suppressor cells can inhibit both primary and secondary IgM and IgG responses in vitro. X-irradiation before activation of peripheral thymus-derived cells by concanavalin A abrogates generation of suppressor cells. After a 48 h activation period, however, the function of concanavalin A-activated suppressor cells is radioresistant. As yet uncertain is whether these suppressor cells are a population of cells distinct from thymus-derived "helper" cells. In certain important regards, the cells mediating these two opposing functions share similar characteristics; the effect observed may be determined by the circumstances of activation or the numbers of activated cells, and may consequently represent different functions of a single thymus-derived regulator cell population.

Desoxyribonucleasen in Mäusenieren unter dem Einfluß von Folsäure / On the Action of Folic Acid on Deoxyribonucleases of Mouse Kidney

1971 ◽  
Vol 26 (6) ◽  
pp. 589-594 ◽  
Author(s):  
K. Tempel
Keyword(s):  
Folic Acid ◽  
Dna Synthesis ◽  
Extreme Values ◽  
Dnase I ◽  
Dnase Ii ◽  
X Irradiation ◽  
Acid Deoxyribonuclease ◽  
High Doses ◽  
Dose Dependent

The behaviour of the in vitro-activities of an alkaline and an acid deoxyribonuclease (DNase I and II, resp.), and of an inhibitor of DNase I of the kidney of mice, as well as of the DNA- and protein-content of kidneys and thymus, was studied in about 500 mice 4 hours to 21 days after exposure to folic acid in doses of 60 — 180 mg/kg body-weight.The most important results can be summarized af follows:1. Activity of DNase I decreased and activities of DNase II and of a DNase I-inhibitor increased under the influence of high doses of folic acid. Significant effects were observed 16 — 24 hours after folic acid-injections. Extreme values (80% decrease [DNase I], 180% increase [DNase II, DNase I-inhibitor]) were reached after 2 and 4 days and were dose-dependent. Control values reappeared within 1 — 3 weeks.2. Protein- and DNA-content of the thymus behaved very similarly to DNase I-activity of the kidney.3. The increase of the DNase II-activity of the kidney under the influence of folic acid resulted from enzyme induction. As to the behaviour of DNase I loss of enzyme out of damaged cells and the induction of a DNase I-inhibitor in the kidney must be taken into account.4. In many systems DNase I may control DNA-synthesis. Preliminary studies on the behaviour of folic acid-induced reaction of the kidney, when inhibited by X-irradiation, Actinomycin D, Actidione, or poly (vinylsulfate), suggest that DNase I-inhibitor plays a certain role in combining protein- and DNA-synthesis by inhibiting DNase I.

Unprogrammierte DNA-Synthese (DNA-Reparatur) in Milz-und Thymuszellen der Ratte nach Einwirkung von UV-Licht, Röntgenstrahlen oder Methylmethansulfonat in vitro / Unscheduled DNA Synthesis (DNA-Repair) within Splenic and Thymic Cells of the Rat under the Influence of UV-Light, X-Irradiation and/or Methyl-methanesulfonate

1980 ◽  
Vol 35 (1-2) ◽  
pp. 106-111 ◽  
Author(s):  
K. Tempel
Keyword(s):  
Dna Repair ◽  
Dna Synthesis ◽  
Excision Repair ◽  
Uv Light ◽  
Methyl Methanesulfonate ◽  
X Rays ◽  
Unscheduled Dna Synthesis ◽  
Splenic Cells ◽  
X Irradiation

Abstract DNA -Repair, Splenocytes, Thymocytes, Irradiation, Methyl-M ethanesulfonate Unscheduled DNA synthesis (UDS) of splenic and thymic cells of the rat has been stimulated in vitro by UV-light (8-128 J × m-2), X-rays (120-3480 rd), methyl-methanesulfonate (MMS), and/or a combination of UV-light and X -irradiation. The height of U DS-induced stim ulation of incorporation of [3H] thymidine into splenic and thymic cell DNA at saturation doses of UV-light (splenic cells: 8, thymic cells: 96 J × m-2) or X -irradiation (splenic cells: 960, thymic cells:~3480 rd) suggest that the greater sensitivity of T-cells (represented by thymic cells) towards UV-light and the greater sensitivity of B-cells (represented by splenic cells) towards X-rays can be explained - at least partly - in terms of less efficient excision repair systems.

NUCLEIC ACID SYNTHESIS IN X-IRRADIATED THYMOCYTES

1966 ◽  
Vol 44 (6) ◽  
pp. 839-852 ◽  
Author(s):  
D. K. Myers ◽  
Kirsten Skov
Keyword(s):  
Dna Synthesis ◽  
Rna Synthesis ◽  
Acid Synthesis ◽  
X Irradiation ◽  
High Concentrations ◽  
Effects Of Radiation ◽  
Inhibition Of Dna Synthesis ◽  
Thymus Cells ◽  
Rna And Dna

The rate of incorporation of thymidine into the deoxyribonucleic acid (DNA) of rat thymocytes in vitro was not immediately affected by low doses of X-radiation, but became progressively more inhibited as the irradiated cells were incubated at 37 °C for periods of up to 6 hours. Ribonucleic acid (RNA) synthesis deteriorated almost at the same rate as DNA synthesis after X-irradiation in vitro, but protein synthesis was slightly more resistant. Addition of 10–50 mM nicotinamide to the irradiated cell suspensions tended to retard the development of this inhibition, particularly at low temperatures, but high concentrations of nicotinamide were also toxic to these cells. The inhibition of DNA synthesis by X-irradiation appeared to follow a qualitatively similar pattern in thymus, spleen, and regenerating liver in vivo.In addition to the inhibition resulting from degenerative processes in the irradiated cells, DNA synthesis in vitro was directly inhibited by 20–30 kr X-radiation. The effects of radiation on DNA synthesis paralleled to some extent its effects on the gel-forming capacity of the deoxyribonucleoprotein from the thymus cells. It is suggested that the normal synthesis of both RNA and DNA in thymocytes depends on the integrity of the deoxyribonucleoprotein.

EFFECT OF X-IRRADIATION ON DNA SYNTHESIS IN EHRLICH ASCITES CARCINOMA CELLS

1965 ◽  
Vol 43 (7) ◽  
pp. 859-864 ◽  
Author(s):  
Shan-Ching Sung
Keyword(s):  
Protein Synthesis ◽  
Dna Synthesis ◽  
Rna Synthesis ◽  
Ehrlich Ascites Carcinoma ◽  
Carcinoma Cells ◽  
Total Rna ◽  
Ehrlich Ascites ◽  
Ehrlich Ascites Cells ◽  
X Irradiation

The rate of DNA synthesis in Ehrlich ascites cells measured immediately after X-irradiation of 500 r for 6 minutes in vitro showed about 15% reduction. However, if X-irradiation was followed by preincubation of the cells, the subsequent synthesis of DNA in the X-irradiated cells was markedly inhibited. Under the same condition, the uptake of thymidine-2-C14, uridine-2-C14, adenine-8-C14, and glycine-1-C14, and protein synthesis in the X-irradiated cells were found to be almost the same as those in the non-irradiated control. RNA synthesis measured as total RNA was only slightly inhibited.

Effect of X-irradiation on gene expression of rat liver chemokines: in vivo and in vitro studies

2008 ◽  
Vol 46 (01) ◽  
Author(s):  
F Moriconi ◽  
H Christiansen ◽  
H Christiansen ◽  
N Sheikh ◽  
J Dudas ◽  
...  
Keyword(s):  
Gene Expression ◽  
Rat Liver ◽  
In Vitro Studies ◽  
X Irradiation

Complement (C5b-9) induces DNA synthesis in rat mesangial cells in vitro

2001 ◽  
Vol 59 (3) ◽  
pp. 905-912
Author(s):  
William G. Couser ◽  
Jeffrey W. Pippin ◽  
Stuart J. Shankland
Keyword(s):  
Dna Synthesis ◽  
Mesangial Cells

Thrombopoietin-Induced Stimulation of Megakaryocyte- Enriched Bone Marrow Cultures

1979 ◽  
Author(s):  
K. L. Kellar ◽  
B. L. Evatt ◽  
C. R. McGrath ◽  
R. B. Ramsey
Keyword(s):  
Bone Marrow ◽  
Dna Synthesis ◽  
Bone Marrow Cells ◽  
Rabbit Plasma ◽  
Bone Marrow Cultures ◽  
Plasma Fractions ◽  
Marrow Cultures ◽  
Stimulation Of

Liquid cultures of bone marrow cells enriched for megakaryocytes were assayed for incorporation of 3H-thymidine (3H-TdR) into acid-precipitable cell digests to determine the effect of thrombopoietin on DNA synthesis. As previously described, thrombopoietin was prepared by ammonium sulfate fractionation of pooled plasma obtained from thrombocytopenic rabbits. A control fraction was prepared from normal rabbit plasma. The thrombopoietic activity of these fractions was determined in vivo with normal rabbits as assay animals and the rate of incorporation of 75Se-selenomethionine into newly formed platelets as an index of thrombopoietic activity of the infused material. Guinea pig megakaryocytes were purified using bovine serum albumin gradients. Bone marrow cultures containing 1.5-3.0x104 cells and 31%-71% megakaryocytes were incubated 18 h in modified Dulbecco’s MEM containing 10% of the concentrated plasma fractions from either thrombocytopenic or normal rabbits. In other control cultures, 0.9% NaCl was substituted for the plasma fractions. 3H-TdR incorporation was measured after cells were incubated for 3 h with 1 μCi/ml. The protein fraction containing thrombopoietin-stimulating activity caused a 25%-31% increase in 3H-TdR incorporation over that in cultures which were incubated with the similar fraction from normal plasma and a 29% increase over the activity in control cultures to which 0.9% NaCl had been added. These data suggest that thrombopoietin stimulates DNA synthesis in megakaryocytes and that this tecnique may be useful in assaying thrombopoietin in vitro.

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