Study of DNA synthesis and mitotic activity of hepatocytes and its relation to angiogenesis in hepatectomised tumour bearing mice

2013 ◽  
pp. n/a-n/a
Author(s):  
Laura B. Andrini ◽  
Marcela N. García ◽  
Ana María Inda ◽  
Ana Lía Errecalde
Keyword(s):  
Dna Synthesis ◽  
Mitotic Activity ◽  
Tumour Bearing

DNA synthesis and mitotic activity during early development of chick lens

1968 ◽  
Vol 17 (5) ◽  
pp. 544-561 ◽  
Author(s):  
Sohan P. Modak ◽  
Georgia Morris ◽  
Tuneo Yamada
Keyword(s):  
Dna Synthesis ◽  
Mitotic Activity ◽  
Early Development ◽  
Chick Lens

Neurotrophic control of events in injured forelimbs of larval urodeles

Development ◽  
1982 ◽  
Vol 69 (1) ◽  
pp. 183-192
Author(s):  
Anthony L. Mescher
Keyword(s):  
Cell Cycle ◽  
Dna Synthesis ◽  
Mitotic Activity ◽  
Mitotic Index ◽  
Elevated Level ◽  
Labelling Index ◽  
Neurotrophic Control ◽  
Epimorphic Regeneration ◽  
Baseline Levels

Denervated forelimbs and contralateral innervated forelimbs of Ambystoma larvae were injured internally distal to the elbow by compression with watchmaker's forceps. Innervated controls completely repaired the crush injury within one week; denervated limbs failed to repair the injury and exhibited varying degrees of limb regression. Histological examination revealed that the process of tissue dedifferentiation initiated by injury was more extensive in denervated, regressing limbs than in controls. In innervated limbs, both the DNA labelling index and the mitotic index peaked approximately 4–6 days after the injury and returned to baseline levels by 10 days. In denervated limbs, the DNA labelling index also increased and remained at an elevated level for at least 2 weeks after the injury, but significant mitotic activity was not observed. The data indicate that intact nerves are not needed for cellular dedifferentiation, cell cycle re-entry, and DNA synthesis in injured limbs, but are required for the cells to proliferate and repair the injury. These results are discussed together with those of similar experiments on the role of nerves during the initiation of epimorphic regeneration in amputated limbs.

scholarly journals DNA CONTENT OF PLACENTAL NUCLEI

1962 ◽  
Vol 13 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Michael Galton
Keyword(s):  
Cell Proliferation ◽  
Dna Synthesis ◽  
Mitotic Activity ◽  
Dna Content ◽  
Reproductive Capacity ◽  
Interphase Nuclei ◽  
Daughter Cells ◽  
Reproductive Ability ◽  
Dna Values ◽  
Rapid Accumulation

The DNA content of individual nuclei in four immature human placentas was determined by microspectrophotometric analysis of Feulgen-stained sections. The absence of mitosis in the syncytiotrophoblast, taken together with the finding of a diploid unimodal distribution, at a time of rapid placental growth, indicated that the syncytiotrophoblast possessed little or no intrinsic reproductive capacity. In contrast, the cytotrophoblast displayed considerable mitotic activity and was found to contain a high proportion of nuclei with DNA values in excess of the diploid amount, corresponding to DNA synthesis in interphase nuclei preparatory to division. From the complementary behavior of the two layers of trophoblast, with respect to evidence of reproductive ability, it is concluded that the rapid accumulation of nuclei in the syncytiotrophoblast, during the early development of the placenta, is accounted for by cell proliferation within the cytotrophoblast followed by alignment and coalescence of some daughter cells in the syncytiotrophoblast.

Hyperprolactinaemia and DNA synthesis in the pituitary gland of the rat

1983 ◽  
Vol 97 (1) ◽  
pp. 65-74 ◽  
Author(s):  
J. A. Burdman ◽  
M. T. Calabrese ◽  
R. M. MacLeod
Keyword(s):  
Dna Synthesis ◽  
Pituitary Gland ◽  
Dopamine Receptor ◽  
Dna Content ◽  
Anterior Pituitary ◽  
Blocking Agent ◽  
Anterior Pituitary Gland ◽  
Host Animal ◽  
Receptor Blocking ◽  
Tumour Bearing

Hyperprolactinaemia produced in rats by the transplanted prolactin-secreting tumours MtTW15 and 7315a significantly (P<0·01) inhibited by 70% the incorporation of [3H]thymidine into the pituitary DNA of the host animals. The weight and the DNA content of the glands were significantly (P<0·01) reduced by 30%. The administration of haloperidol, a dopamine receptor blocking agent, to the tumour-bearing rats increased the suppressed DNA replication in the anterior pituitary glands by approximately 560% in the MtTW15-bearing rat and by 100% in the 7315a-bearing animals. Furthermore, injection of drugs which stimulate prolactin release either by blocking the synthesis of dopamine (α-methyl-p-tyrosine) or the re-uptake of dopamine (reserpine) stimulated DNA synthesis by 800 and 100% respectively in the anterior pituitary gland of rats bearing the MtTW15 tumour. In contrast, lisuride, a dopamine agonist, significantly inhibited the incorporation of [3H]thymidine into the DNA of the pituitary gland of normal but not hyperprolactinaemic rats. Chronically administered oestrogens to hyperprolactinaemic rats increased the weight (100%), DNA content (31%), incorporation of [3H]thymidine into DNA (680%) and synthesis and release of prolactin (300%) in the pituitary gland. The incorporation of [3H]thymidine into tumour DNA was several times higher than in the pituitary gland of the host animal and was not significantly modified by any of the above treatments. Likewise the hyperprolactinaemia of the tumour-bearing rats was not significantly changed. In conclusion, we have shown that hyperprolactinaemia inhibits DNA synthesis in the anterior pituitary gland and this inhibition can be reversed completely by a dopamine receptor blocking agent and by hypothalamic dopamine depleting drugs. We propose that dopamine regulates, either directly or indirectly, DNA synthesis in the lactotrophs of the pituitary gland, which may be responsive to negative feedback mechanisms.

Diurnal changes in mitotic activity and DNA synthesis in normal and tumor tissues of rats

1973 ◽  
Vol 76 (6) ◽  
pp. 1439-1441
Author(s):  
L. V. Sokolova ◽  
A. G. Mustafin ◽  
V. N. Dobrokhotov ◽  
S. I. Baluev
Keyword(s):  
Dna Synthesis ◽  
Mitotic Activity ◽  
Diurnal Changes ◽  
Tumor Tissues
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