Norethindrone Acetate and Testosterone Interactions in Mammary Gland, Uterus and Seminal Vesicles of Mice

The present study tested and compared the antiproliferative and proliferative activities of three antiprogestins on four separate mouse model systems: prepubertal intact and adult ovariectomized (OVX) females, prepubertal intact and adult castrated males. In prepubertal intact males and females and adult castrated males, norethindrone acetate (NA; a synthetic steroid exhibiting progestational and estrogenic activities)- stimulated mammary growth was decreased by antiprogestins: more by RU 46556 (RU) than RU 38486 (MI) and onapristone (ON). In adult OVX females the inhibitory effect of RU and MI was lower than that of ON. Uterine weights were not significantly decreased by MI, were significantly decreased by RU at a lower daily dose (50 μg) but not affected by a high (500 μg) dose. Seminal vesicle weights were increased by RU but not affected by MI in both NA-treated prepubertal and adult castrated males. In adult castrated but not in prepubertal males ON decreased seminal vesicle weights. In 17β-estradiol (E) plus progesterone (Prog)-treated animals of all four model systems, RU (100 μg/d) acted additively with a submaximal daily dose (10 μg) of antiestrogen ICI 182, 780 (ICI) to produce a lower mammary gland growth rate than ICI alone. In uterus, however, no significant effect of a combination of ICI plus RU was noted when compared with ICI alone. In general, our assay could serve as an in vivo tool for the detection of steroid hormone agonist and antagonist activities of newly synthesized analogs of steroid hormones, and natural and man-made chemicals and extracts of environmental samples.

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Bioassay of Steroid Hormone Agonist and Antagonist Activities of Anti-androgens on Mammary Gland, Seminal Vesicles and Spleen of Male Mice

Journal of Veterinary Medicine Series A ◽

10.1046/j.1439-0442.2003.00526.x ◽

2003 ◽

Vol 50 (4) ◽

pp. 204-212 ◽

Cited By ~ 9

Author(s):

J. Skarda

Keyword(s):

Mammary Gland ◽

Steroid Hormone ◽

Seminal Vesicles ◽

Male Mice ◽

Agonist And Antagonist

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Electron Microscopic Study of the Epithelium of the Seminal Vesicle of Aging Rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100050706 ◽

1974 ◽

Vol 32 ◽

pp. 138-139

Author(s):

V. F. Allison ◽

G. C. Fink ◽

G. W. Cearley

Keyword(s):

Cell Growth ◽

Epithelial Cell ◽

Epithelial Cells ◽

Seminal Vesicle ◽

Seminal Vesicles ◽

Epithelial Layer ◽

Epithelial Hyperplasia ◽

Electron Microscopic ◽

Aging Rats ◽

Pseudostratified Epithelium

It is well known that epithelial hyperplasia (benign hypertrophy) is common in the aging prostate of dogs and man. In contrast, little evidence is available for abnormal epithelial cell growth in seminal vesicles of aging animals. Recently, enlarged seminal vesicles were reported in senescent mice, however, that enlargement resulted from increased storage of secretion in the lumen and occurred concomitant to epithelial hypoplasia in that species.The present study is concerned with electron microscopic observations of changes occurring in the pseudostratified epithelium of the seminal vescles of aging rats. Special attention is given to certain non-epithelial cells which have entered the epithelial layer.

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Electron microscopic studies on ultrathin frozen sections of lactating mouse mammary gland

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100081097 ◽

1978 ◽

Vol 36 (2) ◽

pp. 46-47

Author(s):

Jan Zarzycki ◽

Joseph Szroeder

Keyword(s):

Mammary Gland ◽

Protein Denaturation ◽

Chemical Constituents ◽

Freeze Substitution ◽

Electron Microscopic Examination ◽

Mouse Mammary Gland ◽

Electron Microscopic ◽

Preparation Methods ◽

Microscopic Studies ◽

Ultrathin Frozen Sections

The mammary gland ultrastructure in various functional states is the object of our investigations. The material prepared for electron microscopic examination by the conventional chemical methods has several limitations, the most important are the protein denaturation processes and the loss of large amounts of chemical constituents from the cells. In relevance to this,one can't be sure about a degree the observed images are adequate to the realy ultrastructure of a living cell. To avoid the disadvantages of the chemical preparation methods,some autors worked out alternative physical methods based on tissue freezing / freeze-drying, freeze-substitution, freeze-eatching techniqs/; actually the technique of cryoultraraicrotomy,i,e.cutting ultrathin sections from deep frozen specimens is assented as a complete alternative method. According to the limitations of the routine plastic embbeding methods we were interested to analize the mammary gland ultrastructure during lactation by the cryoultramicrotomy method.

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The effect of bromocriptine on mammary-gland ultrastructure of hyperprolactinemic rats

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100111136 ◽

1984 ◽

Vol 42 ◽

pp. 204-205

Author(s):

I.C. Murray

Keyword(s):

Mammary Gland ◽

Dopamine Agonist ◽

Alveolar Epithelium ◽

Mammary Glands ◽

Female Rats ◽

Control Group ◽

Cell Hyperplasia ◽

Once Daily ◽

Long Evans

In women, hyperprolactinemia is often due to a prolactin (PRL)-secreting adenoma or PRL cell hyperplasia. RRL excess stimulates the mammary glands and causes proliferation of the alveolar epithelium. Bromocriptine, a dopamine agonist, inhibits PRL secretion and is given to women to treat nonpuerperal galactorrhea. Old female rats have been reported to have PRL cell hyperplasia or adenoma leading to PRL hypersecretion and breast stimulation. Herein, we describe the effect of bromocriptine and consequently the reduction in serum PRL levels on the ultrastructure of rat mammary glands.Female Long-Evans rats, 23 months of age, were divided into control and bromocriptine-treated groups. The control animals were injected subcutaneously once daily with a 10% ethanol vehicle and were later divided into a normoprolactinemic control group with serum PRL levels under 30 ng/ml and a hyperprolactinemic control group with serum PRL levels above 30 ng/ml.

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Ultrastructural Changes in the Mammary Epithelial Cell Population During Neoplastic Development Induced by A Chemical Carcinogen.

Proceedings, annual meeting, Electron Microscopy Society of America ◽

10.1017/s0424820100091238 ◽

1976 ◽

Vol 34 ◽

pp. 250-251 ◽

Cited By ~ 2

Author(s):

J. Russo ◽

W. Isenberg ◽

M. Ireland ◽

I.H. Russo

Keyword(s):

Mammary Gland ◽

Cell Population ◽

Virgin Female ◽

Histological Change ◽

Mammary Epithelial ◽

Female Rats ◽

Ultrastructural Changes ◽

Post Inoculation ◽

Chemical Carcinogen ◽

Sprague Dawley

The induction of rat mammary carcinoma by the chemical carcinogen DMBA is used as a model for the study of the human disease (1). We previously described the histochemical changes that occur in the mammary gland of DMBA treated animals before the earliest manifested histological change, the intraductal proliferation (IDP), was observed (2). In the present work, we demonstrate that a change in the stable cell population found in the resting mammary gland occurs after carcinogen administration.Fifty-five day old Sprague-Dawley virgin female rats were inoculated intragastrically with 20mg of 7,12-dimethylbenz(a)anthracene (DMBA) in 1ml sesame oil. Non-inoculated, age-matched females were used as controls. Mammary glands from control and inoculated rats were removed weekly from the time of inoculation until 60 days post-inoculation. For electron microscopy, the glands were immersed in Karnovsky's fixative, post-fixed in 1% OsO4, dehydrated, and embedded in an Epon-Araldite mixture. Thick (lμ) sections were stained with 1% toluidine blue and were used for selecting areas for ultrastructural study.

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