Tumors and Hormones

Noble, R. L.

doi:10.1016/b978-0-12-395716-0.50013-9

Cited by 15 publications

(2 citation statements)

References 751 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Under certain conditions polycyclic hydrocarbons are metabolized by these enzymes to metabolites of high carcinogenic potency ( 1 ) . The development of tumors induced by chemical carcinogens is subject to some elements of endocrine control (2)(3)(4), but the mechanisms by which endocrine factors affect chemical carcinogenesis are not understood. I t remains a possibility that during the early phases of carcinogen-tissue interaction hormones modify the metabolic activity of liver and thus increase or decrease the extent of metabolic modification of administered polycyclic hydrocarbons.…”

mentioning

confidence: 99%

Effects of Gonadectomy on the Uptake of Polycyclic Hydrocarbons by Rat Liver Nuclei, DNA, and Histones

Schweppe

Kot

Jungmann

1971

Experimental Biology and Medicine

View full text Add to dashboard Cite

Administration of polycyclic hydrocarbons to rats is followed by an increase in the activities of several of the mixed function oxidases present in the liver. Under certain conditions polycyclic hydrocarbons are metabolized by these enzymes to metabolites of high carcinogenic potency ( 1 ) . The development of tumors induced by chemical carcinogens is subject to some elements of endocrine control (2-4), but the mechanisms by which endocrine factors affect chemical carcinogenesis are not understood. I t remains a possibility that during the early phases of carcinogen-tissue interaction hormones modify the metabolic activity of liver and thus increase or decrease the extent of metabolic modification of administered polycyclic hydrocarbons. The effective level of proximate carcinogens or the modification of the interaction between carcinogen and macromolecules of liver nuclei may be among the biochemical parameters which can be affected by hormones. In the present investigation, we have studied some of the initial phases of the interaction of 7,12-dimethylbenz [a] anthr a~e n e -~H (DMBA) and of benz [ a ] -anthra-~e n e -~H (1,2-BA) with hepatic DNA and histones from intact and gonadectomized male and female rats.MateriaZs and Methods. Intact and gonadectomized male and female Sprague-Dawlrey rats (180 to 200 g) were used throughout the experiments. The time lapse between operation and killing was 2 1 days. The animals were guillotined, after which the livers were cannulated and perfused with ice-cold 0.9% NaCl. Slices were prepared by means of a Stadie-Riggs microtome. The slices (500 mg of wet wt) were placed in a 25-ml Erlenmeyer flask and suspended in 5 ml of 0.05 M sodium phosphate buffer, pH 7.9, containing 2 pCi of 7,1%-dimethylbenz-[~Ianthracene-~H (G) (sp act 750 pCiJ mmole), or 2 pCi of benz[~]anthracene-~H (G) (sp act 750 pCi/mmole) dissolved in 0.1 ml of propylene glycol. Incubations were carried out at 37" in a Dubnoff metabolic incubator in air. At the end of the incubation time the slices were removed from the incubation medium and washed 5 times in 4 ml of ice-cold 0.05 M sodium phosphate buffer, pH 7.9, containing the respective nonradioactive carcinogens (dissolved in propylene glycol) at a concentration of M . The slices were homogenized in 8 ml of 0.05 M sodium phosphate buffer, pH 7.9, containing 0.25 IM sucrose in a Potter-Elvehjem glass homogenizer. The nuclear fraction was isolated and purified by sedimentation through 2.3 M sucrose as described previous-For the isolation of the total histone fraction, nuclei were extracted for 6 hr with three 5-ml portions of ice-cold 0.25 N HCl (6).The combined acid extract was clarified by centrifugation and contained the total acidextractable histone fraction. DNA was extracted from the purified nuclei by a modification of the Kirby procedure (7). DNA was determined with diphenylamine (8). Protein was determined by the method of Lowry et al. (9). For the determination of radioactivity, the samples were dissolved in 2 ml of NCS solubilizer (NCS Tissue Sol...

show abstract

mentioning

confidence: 99%

Effects of Gonadectomy on the Uptake of Polycyclic Hydrocarbons by Rat Liver Nuclei, DNA, and Histones

Schweppe

Kot

Jungmann

1971

Experimental Biology and Medicine

View full text Add to dashboard Cite

show abstract

“…The involvement of hormone-secreting tumours in a wide range of pathological conditions is now becoming more completely understood (Noble, 1964). However, reports of tumours secreting hormones which influence sexual development are scarce.…”

mentioning

confidence: 99%

Sexual precocity due to an intracranial tumour causing unusual testicular secretion of testosterone.

Hutchinson¹,

Brooks²,

Barratt³

et al. 1969

Archives of Disease in Childhood

View full text Add to dashboard Cite

The Nb rat prostatic adenocarcinoma's dose response to methotrexate and adriamycin

Drago

Palmer

1983

Journal of Surgical Oncology

View full text Add to dashboard Cite

The Noble rat prostatic adenocarcinoma, Nb-Pr-A.I.-II, an androgen-insensitive tumor, is the subject of this experiment. Dose responses were carried out with treatment of these tumors with three doses of adriamycin and two doses of methotrexate. Adriamycin treatment resulted in decreased tumor volume and decreased number of metastases in the higher dosage. Methotrexate also decreased metastasis and tumor volume. No animal treated with either of these agents in this protocol had the tumor undergo complete tumor regression, a criteria used in evaluation of chemotherapies with this animal model.

show abstract

Tumors and Hormones

Cited by 15 publications

References 751 publications

Effects of Gonadectomy on the Uptake of Polycyclic Hydrocarbons by Rat Liver Nuclei, DNA, and Histones

Effects of Gonadectomy on the Uptake of Polycyclic Hydrocarbons by Rat Liver Nuclei, DNA, and Histones

Sexual precocity due to an intracranial tumour causing unusual testicular secretion of testosterone.

The Nb rat prostatic adenocarcinoma's dose response to methotrexate and adriamycin

Contact Info

Product

Resources

About