Nuclear incorporation of P as demonstrated by autoradiographs

Howard, Alma; Pelc, S. R.

doi:10.1016/0014-4827(51)90083-3

Cited by 298 publications

(62 citation statements)

References 2 publications

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“…1) warrants further comment, namely the apparent co-ordination of mitosis and DNA replication, represented by the induction of DNA polymerase activity, after androgenic stimulation. On the basis of the classical concept of the cell cycle proposed by Howard & Pelc (1951), DNA replication should occur in the S phase preceding the mitotic event itself, termed the M phase. The similarity in the speed of the androgenic induction of these events in the prostate gland is possibly more apparent than real.…”

Section: Discussionmentioning

confidence: 99%

“…With more individual experimental points in our determination of the time-course of events related to DNA replication, distinction between the induction times of DNA polymerase activity and mitosis may have been evident. Alternatively, it could be argued that individual prostate cells are entering the process of cell division at slightly different rates, resulting in the apparent overlap of the otherwise temporally distinct biochemical events proposed by Howard & Pelc (1951). By using a more contemporary model of cell division (Smith & Martin, 1973) it is possible that prostate cells leave the indeterminate A phase into the determinate B phase at different rates.…”

Section: Discussionmentioning

confidence: 99%

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The androgenic regulation of the activities of enzymes engaged in the synthesis of deoxyribonucleic acid in rat ventral prostate gland

Rennie

Symes

Mainwaring

1975

Biochemical Journal

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1. The restoration of mitosis and growth of the prostate gland of castrated animals by androgens provides a favourable experimental system for studying the hormonal regulation of enzymes engaged in DNA replication. 2. Many DNA polymerase activities were identified in the prostate gland, but only a 9 S form with a particular preference for denatured DNA as template was conspicuously enhanced by androgenic stimulation. 3. Thymidine kinase also provided a sensitive indicator of the hormonal regulation of DNA replication, and on electrophoretic criteria, one discrete form of the enzyme appeared precisely with the onset of mitosis. 4. Evidence is presented to support the view that DNA ligase activity is intimately associated in the process of DNA replication in the prostate gland. 5. A spectrum of deoxyribonuclease activities is present in the prostate gland, but only one form (pI7.0) can safely be said to be implicated in the process of DNA replication. 6. Androgenic stimulation of the prostate gland leads to the appearance of a component capable of denaturing or unwinding prostate DNA. This component is seemingly distinct from RNA or DNA polymerase activities on the basis of several distinct physicochemical characteristics. 7. The conspicuous feature of all the changes in enzyme activities evoked by androgens in the prostate gland is their acute tissue-and steroid-specificity. Such changes could not be mimicked in liver or spleen and the regulatory role ofandrogens could not be simulated by other classes of steroid hormones. Particularly on the basis of studies with the anti-androgen cyproterone acetate, it is concluded that the changes are initially mediated by the androgen-receptor system and the high-affinity binding of 5cr-dihydrotestosterone in the prostate gland. 8. The results are discussed in the context of the mechanism of action of androgens.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

The androgenic regulation of the activities of enzymes engaged in the synthesis of deoxyribonucleic acid in rat ventral prostate gland

Rennie

Symes

Mainwaring

1975

Biochemical Journal

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“…Biochemical analyses at the tissue and organ level have been supplemented by a variety of autoradiographic studies on single cells. Many of these have shown, in accord with the original work of Howard and Pelc (14), that incorporation of precursors takes place only during the interphase (22,31,46,48). It is usually assumed that such uptake is coincident with the duplication of D N A * Supported by funds from the National Science Foundation.…”

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confidence: 84%

Is there "Metabolic" DNA in the Mouse Seminal Vesicle?

Gall

Johnson

1960

The Journal of Cell Biology

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This study was designed to answer the question: Is H3-thymidine uptake by nuclei of the mouse seminal vesicle evidence for DNA synthesis and mitosis, or does it signify some "metabolic" function of DNA unrelated to chromosome duplication?Mice were given an intraperitoneal injection of H3-thymidine. Six hours later Feulgen squashes of the seminal vesicle epithelium were made and covered with autoradiographie stripping film. The silver grains above labeled nuclei were counted, and the Feulgen dye contents of these same nuclei were determined photometrically after removal of the grains from the emulsion. Unlabeled nuclei were also measured.The dye contents of non-radioactive nuclei form a unimodal distribution, indicating that polyploidy is absent from this tissue. The radioactive nuclei fall into two groups. In the first, the average dye content is the same as that of the cold nuclei (2C). In the second, the values range from 2C to 4C.In the 2C to 4C group the grain count is proportional to the dye content, showing that incorporation is correlated with synthesis.The radioactive 2C nuclei arose by mitosis during the course of the experiment. This is shown by the following facts: (1) They frequently occur in pairs. (2) They average smaller than unlabeled 2C nuclei. (3) Their average grain count is approximately half that of the 4C nuclei. (4) Labeled division figures are found. (5) A mitotic rate estimated from the number of labeled 2C nuclei accords reasonably well with one based on the number of observed mitoses.Since the incorporation of thymidine accompanies DNA synthesis and precedes mitosis, there is no reason to postulate a special "metabolic" DNA in this tissue.

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“…These are GAP1 (G 1 ), synthetic phase, GAP2 (G 2 ), and mitosis. The ''GAP'' phases are so named because there is no microscopically obvious cell activity, and the phases were first described 1 before the regulatory molecular processes that occur during the periods named gaps were understood. 2 It is now understood that during the G1 phase, the cell rapidly replicates macromolecules to essentially double its internal components in preparation for cell division.…”

Section: Cell Biology and Divisionmentioning

confidence: 99%

Chemotherapy Agents: A Primer for the Interventional Radiologist

Mihlon¹,

Ray²,

Messersmith

2010

Semin intervent Radiol

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In this article, the authors review the basic principles of cancer chemotherapy and provide an overview of each of the general classes of chemotherapeutic agents with a target audience of interventional radiologists in mind. Special attention is paid to agents used in regional chemotherapy as well as agents commonly included in systemic chemotherapeutic regimens for patients who also require regional chemotherapy.

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Nuclear incorporation of P as demonstrated by autoradiographs

Cited by 298 publications

References 2 publications

The androgenic regulation of the activities of enzymes engaged in the synthesis of deoxyribonucleic acid in rat ventral prostate gland

The androgenic regulation of the activities of enzymes engaged in the synthesis of deoxyribonucleic acid in rat ventral prostate gland

Is there "Metabolic" DNA in the Mouse Seminal Vesicle?

Chemotherapy Agents: A Primer for the Interventional Radiologist

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