HYPERPLASTIC NODULES IN RAT MAMMARY GLANDS FOLLOWING THE FEEDING OF 4-ACETYLAMINOBIPHENYL

1953 ◽  
Vol 31 (2) ◽  
pp. 95-98
Author(s):  
Jules Tuba ◽  
Herbert E. Rawlinson ◽  
M. Shirley Fraser ◽  
Irmgaard Jeske
Keyword(s):  
Virgin Female ◽  
Mammary Glands ◽  
Female Rats ◽  
Mammary Tissue ◽  
Experimental Animals ◽  
Almost All ◽  
Gland Development

Virgin female rats did not respond to dietary 4-acetylaminobiphenyl by the production of tumors in mammary glands. This is attributed to some anticarcinogenic factor(s) in the stock laboratory diet of Purina Fox Checkers, which are composed of natural foodstuffs. However, the carcinogen did stimulate gland development, and after eight months, hyperplastic nodules appeared in almost all the experimental animals but not in the controls. This indicates that suspected carcinogens may be having an effect on mammary tissue even though visible tumors may not be present.

Modeling of fibrocystic mastopathy in experiment on animals

2020 ◽  
Vol 28 (4) ◽  
pp. 429-436
Author(s):  
Svetlana A. Anisimova ◽  
Janna A. Svirina ◽  
Denis A. Maksaev
Keyword(s):  
Mammary Gland ◽  
Virgin Female ◽  
Mammary Glands ◽  
Female Rats ◽  
Fibrocystic Disease ◽  
Drug Induced ◽  
Fibrocystic Mastopathy ◽  
Hormonal Imbalance ◽  
Pathogenetic Factor ◽  
Almost All

Nowadays, hormonal imbalance is proven to be a factor that influences initiation of malignant and benign breast tumors. To study the aspects of participation of sex hormones in damage to organs and tissues, it may be necessary to model a common womens pathology fibrocystic disease of mammary glands characterized by the most pronounced effects of this pathogenetic factor, on experimental animals. Aim. To create a model of fibrocystic disease of mammary gland with the subsequent possibility of studying morphological manifestations of the disease in natural and drug-induced pathomorphism. Materials and Methods. The pathology was induced by intramuscular injection of 0.5 ml of 2% synestrol and 0.5 ml of 2.5% progesterone to virgin female rats on the 1st, 7th, 14th, 21st, 28th and 35th days of the experiment. For examination, histological preparations of inguinal mammary glands were made. The preparations were described and studied using morphometric analysis. Results. In the result of the experiment, pronounced macro- and microscopic alterations of mammary glands were found. Microscopic picture was similar to that observed in fibrocystic mastopathy in women. Almost all the morphometric parameters underwent reliable alterations in correspondence with the given pathology. Conclusion. A model of fibrocystic disease of mammary gland was obtained that may be used for further study of morphogenesis and methods of correction.

Basal Lamina Formation in DMBA Induced Mammary Carcinoma

1977 ◽  
Vol 35 ◽  
pp. 534-535
Author(s):  
I. Russo ◽  
J. Saby ◽  
J. Russo
Keyword(s):  
Mammary Carcinoma ◽  
Virgin Female ◽  
Mammary Glands ◽  
Sesame Oil ◽  
Female Rats ◽  
Ultrastructural Changes ◽  
Post Inoculation ◽  
Intermediate Type ◽  
Sprague Dawley ◽  
Intercellular Spaces

It has been previously demonstrated that DMBA-induced rat mammary carcinoma originates in the terminal end bud (TEB) of the mammary gland by proliferation of intermediate type cells (1). The earliest lesion identified is the intraductal proliferation (IDP), which gives rise to intraductal carcinomas. These evolve to cribriform, papillary and comedo types (2). In the present work, we report the ultrastructural changes that take place in the IDP for the formation of a cribriform pattern.Fifty-five-day-old Sprague Dawley virgin female rats were inoculated intra- gastrically with 20 mg 7,12-dimethylbenz(a)anthracene (DMBA) in 1 ml sesame oil. Non-inoculated, age-matched females were used as controls. Mammary glands from both control and experimental rats were removed weekly from the time of inoculation until 86 days post-inoculation. The glands were fixed and processed for electron microscopy (2).The first change observed in IDP's was the widening of intercellular spaces and the secretion of an electron dense material into these spaces (Fig. 1).

THE INFLUENCE OF RELAXIN ON MAMMARY GLAND DEVELOPMENT IN GUINEA-PIGS AND RABBITS

1952 ◽  
Vol 8 (4) ◽  
pp. 336-NP ◽  
Author(s):  
FERN A. GARRETT ◽  
R. V. TALMAGE
Keyword(s):  
Guinea Pigs ◽  
Mammary Gland Development ◽  
Normal Development ◽  
Mammary Glands ◽  
Mammary Development ◽  
Mammary Tissue ◽  
Total Treatment ◽  
Per Se ◽  
Duct Development ◽  
Gland Development

An attempt has been made to determine the influence of relaxin on the early development of the mammary glands in rabbits and guinea-pigs. Spayed females of both species were treated with α-oestradiol and an extract containing relaxin, after a preliminary course of the steroid alone. In all cases the total treatment was limited to 20 days. Animals given only oestradiol served as controls. While the data presented are insufficient to substantiate without doubt an influence of relaxin per se on the development of the mammary tissue, they indicate that it enhances mammary development. In the guinea-pig this was in the form of a general growth stimulus; in the rabbit it appeared to consist of a transfer of emphasis from primary duct development to that of the entire duct system of the gland. The conclusion drawn from this study is that relaxin acts as a potentiator of oestrogen, working with the latter to produce greater and more normal development of the mammary glands.

THE DISTRIBUTION OF [1,2-3H]TESTOSTERONE IN THE TISSUES OF FEMALE RATS

1966 ◽  
Vol 34 (4) ◽  
pp. 491-496 ◽  
Author(s):  
D. Y. WANG ◽  
STRETTON YOUNG ◽  
R. D. BULBROOK
Keyword(s):  
Mammary Gland ◽  
Post Partum ◽  
Virgin Female ◽  
Mammary Glands ◽  
Female Rats ◽  
Pregnant Rat ◽  
Tumour Bearing ◽  
Mesenteric Fat

SUMMARY (1) The incorporation of [1,2-3H]testosterone in vivo into various tissues of virgin, pregnant, post-partum and tumour-bearing female rats was studied. (2) In virgin female rats the clearance of radioactivity from mesenteric fat, mammary gland, uterus, spleen, lung and blood was similar. This similarity in the rates of clearance of radioactivity for all the tissues examined was also found for the tissues of pregnant, post-partum, and tumour-bearing rats. (3) After the administration of [1,2-3H]testosterone different amounts of radioactivity were found in each of the tissues examined. In virgin rats the levels of incorporation were fat > uterus ≥ mammary gland > lung > blood ≥ spleen. This pattern was also obtained in post-partum and tumour-bearing animals; the tumours in the latter behaved in a similar way to normal mammary glands. In the pregnant rat, the foetus incorporated the least amount of radioactivity.

Expression levels of STAT5A and STAT5B in mammary parenchymal tissue from Upton-Meishan and Large White gilts

2002 ◽  
Vol 82 (4) ◽  
pp. 507-518 ◽  
Author(s):  
M. F. Palin ◽  
D. Beaudry ◽  
C. Roberge ◽  
C. Farmer
Keyword(s):  
Mammary Gland ◽  
Mammary Gland Development ◽  
Target Genes ◽  
Mammary Glands ◽  
Mammary Tissue ◽  
Mrna Levels ◽  
Large White ◽  
Parenchymal Tissue ◽  
Tissue Weight ◽  
Gland Development

The implication of STAT5A and STAT5B in mammary gland development and maintenance of lactation is well documented in rodents and humans. However, little is known regarding their roles in mammary gland development during gestation in pigs. We identified and analyzed the complete coding sequences of swine STAT5A and STAT5B and evaluated their mRNA levels in mammary glands of gestating gilts (day 110) in two different breeds, Upton-Meishan and Large White. Sequence analysis revealed a new APASA insertion in the STAT5A amino acid sequence that is in close proximity to residue Tyr 699 and whose phosporylation leads to the activation of target genes’ transcription. STAT5A mRNA levels were higher in Upton-Meishan than in Large White. In both breeds, STAT5B mRNA levels were higher than those of STAT5A , which is contrary to what was found in other mammals. A correlation between circulating IGF-I levels and STAT5B mRNA levels in the mammary gland was noticed in the Upton-Meishan breed only. STAT5B mRNA levels in mammary tissue of Large White gilts were highly correlated with extra-parenchymal tissue weight, parenchymal tissue weight, total parenchymal DNA, RNA and RNA/DNA ratio. In Upton-Meishan gilts, correlations were observed only between extra-parenchymal weight and STAT5A and STAT5B mRNA levels. These results indicate that there are significant differences in mRNA levels of STAT5A and STAT5B in the mammary glands of pregnant gilts when compared to other mammals, and between swine breeds. Key words: Mammary glands, signal transducers, pregnancy, kinases, pig, expression

Initiation of lactation in rats by nonspecific stresses

1960 ◽  
Vol 198 (5) ◽  
pp. 1103-1106 ◽  
Author(s):  
Charles S. Nicoll ◽  
P. K. Talwalker ◽  
Joseph Meites
Keyword(s):  
Anterior Pituitary ◽  
Corn Oil ◽  
Virgin Female ◽  
Mammary Glands ◽  
Female Rats ◽  
Common Mechanism ◽  
Duct System ◽  
Once Daily ◽  
Intense Light

Sixty mature, virgin female rats were divided into six groups of 10 each and injected subcutaneously for 10 days with 10 µg estradiol in 0.1 cc corn oil. For the following 5 days the groups were treated as follows: 1) controls, 0.1 cc saline injected subcutaneously once daily; 2) severe cold (0°C) 24 hr/day; 3) intense light and heat for 12 hr/day; 4) restraint, 12 hr/day; 5) starvation, no food or water for 5 days; 6) subcutaneous injection of 0.1 cc or 0.2 cc of 10% formaldehyde once daily. The mammary glands of the control rats regressed from a lobulo-alveolar system to a bare duct system during the period of saline injections. The stressed groups all showed variable degrees of lactation after treatment. It is concluded that nonspecific stresses can promote the secretion of prolactin and ACTH from the anterior pituitary in amounts adequate to induce lactation in estrogen-primed rats. The possible role of stresses in initiating lactation at parturition and under other circumstances is considered, and a common mechanism controlling the secretion of ACTH and prolactin is postulated.

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

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.

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

1976 ◽  
Vol 34 ◽  
pp. 250-251 ◽  
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.

Ultrastructure and Frequency of Mastitis Caused by Ovine Progressive Pneumonia Virus Infection in Sheep

1986 ◽  
Vol 23 (2) ◽  
pp. 184-189 ◽  
Author(s):  
P. Deng ◽  
R. C. Cutlip ◽  
H. D. Lehmkuhl ◽  
K. A. Brogden
Keyword(s):  
Virus Infection ◽  
Mammary Glands ◽  
Infected Sheep ◽  
Mammary Tissue ◽  
Target Organs ◽  
Cellular Debris ◽  
Ovine Progressive Pneumonia

Twenty-five sheep, experimentally ( n = 15) or naturally ( n = 6) infected with ovine progressive pneumonia virus and noninfected controls ( n = 4), were evaluated for histological and ultrastructural lesions of mastitis. Histologically, nine of 15 experimentally infected sheep and all six naturally infected sheep had lympho-plasmacytic mastitis. Severity of the lesion increased with length of time after infection. Periductal lymphatic nodules were seen in five sheep experimentally infected for 2.8 years or longer and in five naturally infected sheep that wore 3.7 years old or older. Ultrastructurally, responses to ovine progressive pneumonia virus were diffuse lympho-plasmacytic infiltrates in glandular interstitium, lymphocytic and occasional plasmacytic infiltrates in ductal walls and lumens, lymphoblasts surrounded by small lymphocytes in glandular interstitium, and degeneration of epithelium releasing cells and cellular debris into the lumen. Based on the prevalence of lesions, the mammary tissue was more susceptible to ovine progressive pneumonia virus than other target organs: lung, brain, and synovium. Lesions did not differ between breeds of sheep. Ovine progressive pneumonia virus was not seen in the mammary tissue but was isolated from 15 of 17 mammary glands.

The Effect of Sodium Nitrite on Experimental Animals

1942 ◽  
Vol 6a (1) ◽  
pp. 63-73 ◽  
Author(s):  
H. L. A. Tarr ◽  
N. M. Carter
Keyword(s):  
Sodium Nitrite ◽  
Lethal Dose ◽  
Oral Route ◽  
Female Rats ◽  
Male Rats ◽  
Subcutaneous Route ◽  
Healthy Male ◽  
Experimental Animals ◽  
White Rats ◽  
Healthy Female

Incorporation of sodium nitrite in the diet of cats and white rats on the basis of an average sized man consuming 1 lb. (454 g.) of fish containing 0.2 per cent (908 mg.) of this salt daily for six days each week does not appear to affect their growth rate nor the development (weight) of their thyroid, heart, lungs, spleen, liver, kidneys or adrenals. The fecundity of white rats as judged by their ability to breed and raise normal litters is apparently not affected thereby. The lethal dose of sodium nitrite by oral route is about 1.1 to 2.0 g./kg. for healthy male rats, 0.46 to 1.2 g./kg. for healthy female rats and 0.073 g./kg. for cats (one animal). The lethal dose by subcutaneous route is about 0.19 to 0.20 g./kg. for healthy male rats and 0.057 to 0.13 g./kg. for healthy female rats.

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