Antiprogesterone and antiglucocorticoid actions of RU 486 on rabbit mammary gland explant cultures. Evidence for a persistent inhibitory action of residual progesterone upon the mammary tissue

1987 ◽  
Vol 28 (4) ◽  
pp. 371-377 ◽  
Author(s):  
G.A. Jahn ◽  
L.-M. Houdebine ◽  
J. Djiane
Keyword(s):  
Mammary Gland ◽  
Inhibitory Action ◽  
Mammary Tissue ◽  
Ru 486 ◽  
Explant Cultures

scholarly journals Collagen molecular phenotypic switch between non-neoplastic and neoplastic canine mammary tissues

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Masahiko Terajima ◽  
Yuki Taga ◽  
Becky K. Brisson ◽  
Amy C. Durham ◽  
Kotaro Sato ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Mammary Gland ◽  
Mammary Carcinoma ◽  
Cancer Biology ◽  
Type I Collagen ◽  
Critical Role ◽  
Premature Death ◽  
Mammary Tissue ◽  
Type I ◽  
Cross Links

AbstractIn spite of major advances over the past several decades in diagnosis and treatment, breast cancer remains a global cause of morbidity and premature death for both human and veterinary patients. Due to multiple shared clinicopathological features, dogs provide an excellent model of human breast cancer, thus, a comparative oncology approach may advance our understanding of breast cancer biology and improve patient outcomes. Despite an increasing awareness of the critical role of fibrillar collagens in breast cancer biology, tumor-permissive collagen features are still ill-defined. Here, we characterize the molecular and morphological phenotypes of type I collagen in canine mammary gland tumors. Canine mammary carcinoma samples contained longer collagen fibers as well as a greater population of wider fibers compared to non-neoplastic and adenoma samples. Furthermore, the total number of collagen cross-links enriched in the stable hydroxylysine-aldehyde derived cross-links was significantly increased in neoplastic mammary gland samples compared to non-neoplastic mammary gland tissue. The mass spectrometric analyses of type I collagen revealed that in malignant mammary tumor samples, lysine residues, in particular those in the telopeptides, were markedly over-hydroxylated in comparison to non-neoplastic mammary tissue. The extent of glycosylation of hydroxylysine residues was comparable among the groups. Consistent with these data, expression levels of genes encoding lysyl hydroxylase 2 (LH2) and its molecular chaperone FK506-binding protein 65 were both significantly increased in neoplastic samples. These alterations likely lead to an increase in the LH2-mediated stable collagen cross-links in mammary carcinoma that may promote tumor cell metastasis in these patients.

I.—On the Pregnancy Rate in the Lactating Mouse and the Effect of Suckling on the Duration of Pregnancy

1932 ◽  
Vol 51 ◽  
pp. 1-7 ◽  
Author(s):  
L. Mirskaia ◽  
F. A. E. Crew
Keyword(s):  
Mammary Gland ◽  
Corpus Luteum ◽  
Pregnancy Rate ◽  
Inhibitory Action ◽  
Reproductive Activity ◽  
Delayed Implantation ◽  
Prolonged Pregnancy ◽  
Suggested Explanation ◽  
Duration Of Pregnancy

Summary1. The pregnancy rate of primiparæ, suckling their young, was, in this experiment, 24·1 per cent.; that of multiparæ suckling their young, 50 per cent. It is shown that this difference is not due to differences in the incidence of ovulation associated with postpartum œstrus. The suggested explanation of this difference between puberal and adult groups is that a certain level of somatic maturity is a prerequisite for full reproductive activity.2. In all cases the duration of pregnancy was prolonged. The degree of prolongation was variable and could not be related to the number of young in the uterus or suckling. The results provide no support for the suggestion that this prolongation, due to delayed implantation of the fertilised ova, is to be referred to an inhibitory action on the part of the mammary gland. The suggestion is made that the delayed implantation and prolonged pregnancy are due to inability on the part of the corpus luteum to cater adequately for implantation and lactation synchronously.

Bovine mammary epithelial cells, initiators of innate immune responses to mastitis

2005 ◽  
Vol 45 (8) ◽  
pp. 757 ◽  
Author(s):  
C. Gray ◽  
Y. Strandberg ◽  
L. Donaldson ◽  
R. L. Tellam
Keyword(s):  
Immune Response ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Mammary Epithelial Cells ◽  
Vital Role ◽  
Mammary Epithelial ◽  
Innate Immune ◽  
Mammary Tissue ◽  
Effector Cells ◽  
Bovine Mammary Epithelial Cells

Innate immunity plays a vital role in the protection of the bovine mammary gland against mastitis. Until recently, the migration of effector cells such as neutrophils and monocytes into the mammary gland was thought to provide the only defence against invading pathogens. However, mammary epithelial cells may also play an important role in the immune response, contributing to the innate defence of the mammary tissue through secretion of antimicrobial peptides and attraction of circulating immune effector cells. This paper reviews the innate immune pathways in mammary epithelial cells and examines their role in the initiation of an innate immune response to Gram-positive and Gram-negative bacteria.

scholarly journals Rat mammary-gland fatty acid synthase. A simple purification procedure and stoicheiometry of CoA ester binding

1982 ◽  
Vol 203 (1) ◽  
pp. 45-50 ◽  
Author(s):  
P M Ahmad ◽  
D S Feltman ◽  
F Ahmad
Keyword(s):  
Mammary Gland ◽  
Fatty Acid ◽  
Fatty Acid Synthase ◽  
Specific Activity ◽  
Simple Procedure ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Performic Acid ◽  
Mammary Tissue ◽  
Rat Mammary Gland

A simple procedure was devised which allows purification of rat lactating-mammary-gland fatty acid synthase to a high degree of purity, with recoveries of activity exceeding 50%. Over 50 mg of enzyme was isolated from 60 g of mammary tissue. The specific activity of the purified enzyme was about 2.5 mumol of NADPH oxidized/min per mg of protein at 37 degrees. The enzyme appeared homogeneous by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis and by immunodiffusion analysis. Each mol (Mr 480 000) of the enzyme bound 3 mol of acetyl and 3-4 mol of malonyl groups when the binding experiments were performed at 0 degrees for 30 s. The presence of NADPH did not influence the binding stoicheiometry for these acyl-CoA derivatives. Approx. 2 mol of taurine was found per mol of the performic acid-oxidized enzyme, suggesting that there were 2 mol of 4′-phosphopantetheine in the native enzyme. Rat mammary-gland fatty acid synthase required free CoA for activity.

Mammary gland biopsy does not affect lactation performance in sows

2007 ◽  
Vol 87 (2) ◽  
pp. 281-284 ◽  
Author(s):  
R. N. Kirkwood ◽  
J. Pérez Laspiur ◽  
N. K. Ames ◽  
J. B. Moore ◽  
A. Cegielski ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Feed Intake ◽  
Somatic Cell Count ◽  
Average Daily Gain ◽  
Mammary Tissue ◽  
Molecular Characteristics ◽  
Lactation Performance ◽  
Voluntary Feed Intake ◽  
Daily Gain

To determine morphological and molecular characteristics of porcine mammary tissue in vivo, mammary tissue was collected from 18 sows at 3 to 6 d of lactation and 17 to 19 d of lactation using a biopsy technique. The success of the technique was determined by monitoring lactation performance, as evidenced by sow rectal temperature, voluntary feed intake, milk somatic cell count, and piglet average daily gain. Up to 1.7 g of mammary tissue was collected at each biopsy without decreasing sow feed intake or piglet growth. Key words: Biopsy, mammary gland, lactation, sow

Transforming growth factor beta3 induces cell death during the first stage of mammary gland involution

Development ◽  
2000 ◽  
Vol 127 (14) ◽  
pp. 3107-3118 ◽  
Author(s):  
A.V. Nguyen ◽  
J.W. Pollard
Keyword(s):  
Cell Death ◽  
Mammary Gland ◽  
Transforming Growth Factor ◽  
Alveolar Epithelium ◽  
Mammary Epithelium ◽  
Significant Inhibition ◽  
Mammary Tissue ◽  
Lactogenic Hormone ◽  
Null Mutant Mice ◽  
Transforming Growth Factor Beta3

Involution of the mammary gland following weaning is divided into two distinct phases. Initially, milk stasis results in the induction of local factors that cause apoptosis in the alveolar epithelium. Secondly after a prolonged absence of suckling, the consequent decline in circulating lactogenic hormone concentrations initiates remodeling of the mammary gland to the virgin-like state. We have shown that immediately following weaning TGFbeta3 mRNA and protein is rapidly induced in the mammary epithelium and that this precedes the onset of apoptosis. Unilateral inhibition of suckling and hormonal reconstitution experiments showed that TGFbeta3 induction is regulated by milk stasis and not by the circulating hormonal concentration. Directed expression of TGFbeta3 in the alveolar epithelium of lactating mice using a beta-lactoglobulin promoter mobilized SMAD4 translocation to the nucleus and caused apoptosis of these cells, but not tissue remodeling. Transplantation of neonatal mammary tissue derived from TGFbeta3 null mutant mice into syngenic hosts resulted in a significant inhibition of cell death compared to wild-type mice upon milk stasis. These results provide direct evidence that TGFbeta3 is a local mammary factor induced by milk stasis that causes apoptosis in the mammary gland epithelium during involution.

The role of the mammary gland during heat stress

2019 ◽  
Author(s):  
◽  
Ricardo Oliveira Rodrigues
Keyword(s):  
Blood Flow ◽  
Heat Stress ◽  
Mammary Gland ◽  
Dairy Cows ◽  
Prolonged Exposure ◽  
Transcriptional Profiling ◽  
Mammary Tissue ◽  
Secretory Cells ◽  
University Of Missouri ◽  
Lactating Dairy Cows

[ACCESS RESTRICTED TO THE UNIVERSITY OF MISSOURI AT REQUEST OF AUTHOR.] Disruptive effects of climate change, such as increasing environmental temperature, have direct impacts on economic viability and efficiency of food production. In lactating dairy cows, heat stress reduces milk production and alters function of mammary secretory cells, at least partly by disturbing local protein metabolism. We hypothesized that hyperthermia would not only reduce mammary blood flow but would also reduce mammary extraction of nutrients from blood. In addition, we hypothesized that transcriptional profiling of mammary tissue would reveal disruption of cellular homeostasis. Our objective was to determine the effects of hyperthermia on mammary function. More specifically, we aimed to profile mammary blood flow and the changes in mammary transcriptome of heat-stressed lactating dairy cows. We investigated the effects of early and prolonged exposure of lactating dairy cows to hyperthermia by exposing cows to programmed constantly elevated temperature and humidity to induce and maintain body temperature approximately 1[degree]C above normal. Experiments were conducted to evaluate the production responses of hyperthermic lactating dairy cows, to characterize total and nutritive mammary blood flow, and to elucidate the regulation of mammary function during early and prolonged exposure to hyperthermia. Results from these studies established that 1) hyperthermia reduces total and nutritive mammary blood flow, limiting nutrient disappearance across the mammary gland; 2) hyperthermia does not induce shunting of blood away from the gland; 3) hyperthermia affects mammary tissue transcriptome, mainly altering processes associated with ECM and cell adhesion; 4) the effects of exposure to prolonged heat stress on mammary gene expression are distinct from the effects of feed restriction, in lactating dairy cows; and 5) mammary function is reestablished within 8 days after cessation of heat stress.

scholarly journals The lactose synthetase particles of lactating bovine mammary gland. Preparation of particles with intact lactose synthetase

1968 ◽  
Vol 109 (2) ◽  
pp. 169-176 ◽  
Author(s):  
R. G. Coffey ◽  
F. J. Reithel
Keyword(s):  
Mammary Gland ◽  
Succinate Dehydrogenase ◽  
Ultrasonic Treatment ◽  
Subcellular Distribution ◽  
Size Range ◽  
Mammary Tissue ◽  
Synthetase Activity ◽  
Bovine Mammary Gland ◽  
Particulate Form ◽  
Novel Method

1. The particulate form of lactating bovine mammary lactose synthetase activity is shown to be more highly organized than previously reported. 2. A novel method of shattering frozen mammary tissue with effective cell disruption is described. 3. The apparent subcellular distribution of lactose synthetase was shown to reflect the method of homogenization. 4. After mild homogenization particles associated with a high content of intact lactose synthetase activity sedimented in the lysosome size range between 5×104 and 3×105g-min. 5. Lactose synthetase was dissociated and solubilized by VirTis homogenization and ultrasonic treatment. The activities and behaviour of UDP-galactose hydrolase, succinate dehydrogenase, β-glucuronidase and phosphodiesterase I were compared. 6. Inhibition of UDP-galactose hydrolase by UTP and α-lactalbumin was observed.

scholarly journals Expression and localisation of oestrogen and progesterone receptors in the bovine mammary gland during development, function and involution

2003 ◽  
Vol 177 (2) ◽  
pp. 305-317 ◽  
Author(s):  
D Schams ◽  
S Kohlenberg ◽  
W Amselgruber ◽  
B Berisha ◽  
MW Pfaffl ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Mrna Expression ◽  
Western Blotting ◽  
Mammary Gland Development ◽  
Mammary Tissue ◽  
Positive Staining ◽  
Bovine Mammary Gland ◽  
Total Rna ◽  
Gland Development

It is now well established that oestrogen and progesterone are absolutely essential for mammary gland development. Lactation can be induced in non-pregnant animals by sex steroid hormone treatment. Most of the genomic actions of oestrogens are mediated by two oestrogen receptors (ER)-alpha and ERbeta, and for gestagens in ruminants by the progesterone receptor (PR). Our aim was the evaluation of mRNA expression and protein (localisation and Western blotting) during mammogenesis, lactogenesis, galactopoiesis (early, middle and late) and involution (8, 24, 28, 96-108 h and 14-28 days after the end of milking) in the bovine mammary gland (total no. 53). During these stages, the mRNA was assessed by means of real-time RT-PCR (LightCycler). The protein for ERalpha, ERbeta and PR was localised by immunohistochemistry and Western blotting. The mRNA expression results indicated the existence of ERalpha, ERbeta and PR in bovine mammary gland. Both ERalpha and PR are expressed in fg/ micro g total RNA range. The highest mRNA expression was found for ERalpha and PR in the tIssue of non-pregnant heifers, followed by a significant decrease to a lower level at the time of lactogenesis with low concentrations remaining during lactation and the first 4 weeks of involution. In contrast, the expression of ERbeta was about 1000-fold lower (ag/ micro g total RNA) and showed no clear difference during the stages examined, with a significant increase only 2-4 weeks after the end of milking. Immunolocalisation for ERalpha revealed a strong positive staining in nuclei of lactocytes in non-pregnant heifers, became undetectable during pregnancy, lactogenesis and lactation, and was again detectable 14-28 days after the end of milking. In contrast, PR was localised in the nuclei of epithelial cells in the mammary tIssue of non-pregnant heifers, in primigravid animals, and during late lactation and involution. During lactogenesis, peak and mid lactation, fewer nuclei of epithelial cells were positive, but increased staining of the cytoplasm of epithelial cells was obvious. ERalpha and ERbeta protein was found in all mammary gland stages examined by Western blotting. In contrast to mRNA expression, the protein signal for ERalpha was weaker in the tIssue of non-pregnant heifers and during involution (4 weeks). ERbeta protein showed a stronger signal (two isoform bands) in non-pregnant heifers and 4 weeks after the end of milking. This correlated with the mRNA expression data. Three isoforms of PR (A, B and C) were found by Western blotting in the tIssue of non-pregnant heifers, but only isoform B remained during the following stages (lactogenesis, galactopoiesis and involution). In conclusion, the mRNA expression and protein data for ER and PR showed clear regulatory changes, suggesting involvement of these receptors in bovine mammary gland development and involution.

Uteroplacental insufficiency alters the mammary gland response to lactogenic hormones in vitro

2008 ◽  
Vol 20 (4) ◽  
pp. 460 ◽  
Author(s):  
Rachael O'Dowd ◽  
Mary E. Wlodek ◽  
Kevin R. Nicholas
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Postnatal Growth ◽  
Mammary Development ◽  
Mammary Tissue ◽  
Sham Surgery ◽  
Uterine Vessel ◽  
Lactogenic Hormones ◽  
Vessel Ligation

Adequate mammary development and coordinated actions of lactogenic hormones are essential for the initiation of lactation. Pregnancies compromised by uteroplacental insufficiency impair mammary development and lactation, further slowing postnatal growth. It is not known whether the initiation of lactation or galactopoesis is compromised. Uteroplacental insufficiency induced in rats by bilateral uterine vessel ligation (Restricted) or sham surgery (Control) on Day 18 of gestation preceded collection of mammary tissue on Day 20 of pregnancy. Mammary explants were cultured with combinations of insulin, cortisol and prolactin and analysed for α-lactalbumin and β-casein gene expression. Mammary tissue from late pregnant Restricted rats had elevated α-lactalbumin, but not β-casein, mRNA, which is consistent with premature lactogenesis resulting from an early decline in peripheral maternal progesterone. Explants from Restricted rats were more responsive to hormone stimulation after 3 days in culture, indicating that compromised galactopoesis, not lactogenesis, most likely leads to the reduced growth of suckled pups.

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