Abstract PS17-28: Abrupt involution of lactating mammary gland induces metabolic reprogramming conducive to pro-tumorigenic changes

2021 ◽  
Author(s):  
Neelam Shinde ◽  
Kirti Kaul ◽  
Allen Zhang ◽  
Saba Mehra ◽  
Resham Mawalkar ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Metabolic Reprogramming ◽  
Lactating Mammary Gland

EFFECT OF LOCALLY IMPLANTED OESTROGEN ON THE RESPONSE OF THE RAT'S LACTATING MAMMARY GLAND TO OXYTOCIN

1973 ◽  
Vol 73 (4) ◽  
pp. 700-712 ◽  
Author(s):  
J. D. Bruce ◽  
X. Cofre ◽  
V. D. Ramirez
Keyword(s):  
Mammary Gland ◽  
Mammary Glands ◽  
Myoepithelial Cells ◽  
Recording System ◽  
Saline Infusion ◽  
High Dose ◽  
Low Doses ◽  
Milk Ejection ◽  
Lactating Mammary Gland ◽  
Small Rise

ABSTRACT On the day following delivery (day 1 of lactation) one abdominal mammary gland was implanted with oestrogen and the contralateral gland received an empty needle. At 2, 5 or 10 days of lactation the rats were anaesthetized with pentobarbital and the nipples of both abdominal glands were cannulated and their pressures recorded by means of transducers coupled to an amplifier and recording system. The normal mammary glands of 5-day lactating rats responded to very low doses of oxytocin (Syntocinon®, Sandoz) (5× 10−8 mU) with a rhythmic elevation in pressure. However, saline infusion also evoked a small rise in intra-mammary pressure. Earlier (2 days) and later (10 days) in lactation the responses were smaller. Oestrogen decreases significantly the milk ejection response to oxytocin, and the effect was maximal at day 10 of lactation. Histological observations confirmed the diminished reaction of the gland to oxytocin, since the milk was retained in the alveoli of rats bearing a mammary-oestrogen implant. A paradoxical rise in pressure was detected in normal as well as in oestrogen-implanted glands when the lowest dose of oxytocin was injected in lactating rats which had previously received a high dose of oxytocin (50 mU or 500 mU). These results reinforce the hypothesis that oestrogen alters the milk ejection response to oxytocin and that the mechanism is probably related to changes in the contractility of the myoepithelial cells.

ÜBER DIE WIRKUNG PHARMAKOLOGISCHER OXYTOCINDOSEN AUF DIE MILCHDRÜSE

1960 ◽  
Vol XXXIV (IV) ◽  
pp. 543-557 ◽  
Author(s):  
B. Berde ◽  
A. Cerletti
Keyword(s):  
Mammary Gland ◽  
Intravenous Administration ◽  
Intravenous Infusion ◽  
Intranasal Administration ◽  
Intramuscular Injection ◽  
Different Types ◽  
Lactating Mammary Gland ◽  
Synthetic Oxytocin

ABSTRACT A study was made of the influence of pharmacological amounts of synthetic oxytocin (»Syntocinon«) on the lactating mammary gland of the rabbit. The drug was given by intravenous infusion, by intramuscular injection and by intranasal administration. Two different types of reaction were noted: a tonic reaction, i. e. a lasting increase in pressure in the mammary gland without significant fluctuations, or a rhythmic reaction, i. e. a series of increases in pressure at more or less regular intervals. In order to elicit reactions approximately identical in intensity and character with those produced by intravenous infusion, it was necessary to give approximately 1.5 to 8.0 times as much by intramuscular injection and approximately 10 to 100 times as much by intranasal administration. Intravenous administration of adrenaline transiently suppressed a long-lasting reaction to oxytocin.

The calcium-sensing receptor regulates PTHrP production and calcium transport in the lactating mammary gland

Bone ◽  
2006 ◽  
Vol 38 (6) ◽  
pp. 787-793 ◽  
Author(s):  
Laleh Ardeshirpour ◽  
Pamela Dann ◽  
Martin Pollak ◽  
John Wysolmerski ◽  
Joshua VanHouten
Keyword(s):  
Mammary Gland ◽  
Calcium Transport ◽  
Calcium Sensing Receptor ◽  
Calcium Sensing ◽  
Lactating Mammary Gland

scholarly journals Evidence for conservation of dietary lipid in the rat during lactation and the immediate period after removal of the litter. Decreased oxidation of oral [1-14C]triolein

1986 ◽  
Vol 239 (1) ◽  
pp. 233-236 ◽  
Author(s):  
C M Oller do Nascimento ◽  
D H Williamson
Keyword(s):  
Adipose Tissue ◽  
Mammary Gland ◽  
Lipoprotein Lipase ◽  
Relative Activity ◽  
Dietary Lipid ◽  
Litter Removal ◽  
Lactating Mammary Gland ◽  
14Co2 Production

Production of 14CO2 from an oral load of [1-14C]triolein was greatly decreased (70%) in lactating rats or immediately after (24-48 h) removal of the litter, compared with virgin rats. This decreased oxidation of dietary lipid was accompanied by accumulation of 14C-labelled lipid in lactating mammary gland or adipose tissue (after litter removal). No difference in 14CO2 production between lactating and virgin rats was observed when [1-14C]octanoate was administered. It is concluded that a major factor in this conservation of dietary triacylglycerol is the relative activity of lipoprotein lipase in the tissues.

scholarly journals Molecular cloning, functional characterization, tissue expression and polymorphism analysis of buffalo PRDX6 gene

2021 ◽  
Author(s):  
Shengnan Sun ◽  
Gongxuan Chen ◽  
Zhenping Hou ◽  
Xuelei Zhang ◽  
Guitao Jiang ◽  
...  
Keyword(s):  
Small Intestine ◽  
Mammary Gland ◽  
Differential Expression Analysis ◽  
Functional Characterization ◽  
Tissue Expression ◽  
Functional Domain ◽  
Polymorphism Analysis ◽  
River Buffalo ◽  
Nucleotide Polymorphisms ◽  
Lactating Mammary Gland

PRDX6 is a bifunctional protein involved in antioxidant regulation and phospholipid metabolism. Previous studies have shown that PRDX6 is involved in some biological pathways and networks related to lactation. The aim of this study was to explore the characteristics, function, tissue expression and variation of buffalo PRDX6 gene. We cloned and characterized the complete coding sequence (CDS) of buffalo PRDX6. The CDS of PRDX6 for swamp and river buffalo is the same, which consists of 675 nucleotides and encodes a protein of 224 amino acids. Buffalo PRDX6 contains one PRX_1cys functional domain (AA 7–222), which is probably related to the regulation of oxidative stress. Multi-tissue differential expression analysis showed that buffalo PRDX6 was highly expressed in the muscle, brain, lung and small intestine during non-lactation and lactation, and there were significant differences in expression in all the tissues except the small intestine between the two periods. It is worth noting that the mRNA abundance of buffalo PRDX6 in non-lactating mammary gland is higher than that in lactating mammary gland. Among the two single nucleotide polymorphisms (SNPs) identified in the CDS in this study, c.261C>T is shared by the two types of buffalo with different allelic frequencies, and c.426T>G is found only in river buffalo. The c.426T>G is non-synonymous, resulting in the amino acid substitution p.Asn142Lys. Only one nucleotide differential site is identified in PRDX6 gene between buffalo and other species of Bovidae. Phylogenetic analysis indicated that buffalo PRDX6 has a closer genetic relationship with that of the species in Bovidae. These results indicate that PRDX6 probably plays a crucial role in the mammary gland of buffalo. This study provides the foundation for further functional studies of PRDX6 in buffalo.

scholarly journals Cytosol oestrogen receptor of lactating mammary gland. Effect of heparin on the aggregation of the receptor and interaction of the receptor with heparin-Sepharose

1978 ◽  
Vol 171 (1) ◽  
pp. 137-141 ◽  
Author(s):  
F Auricchio ◽  
A Rotondi ◽  
P Sampaolo ◽  
E Schiavone
Keyword(s):  
Mammary Gland ◽  
Oestrogen Receptor ◽  
High Speed ◽  
Gradient Centrifugation ◽  
Gel Filtration ◽  
Sedimentation Coefficient ◽  
Large Aggregate ◽  
Low Salt ◽  
Lactating Mammary Gland ◽  
Stokes Radius

1. An oestrogen receptor is present in low-salt cytosol of the mammary gland of lactating mice as a large aggregate; it is excluded from gel matrix when filtered on a Sephadex G-200 column and sediments at 7S in sucrose gradients. After incubation of cytosol with heparin, the receptor is dissociated. On a Sephadex G-200 column, it is included in the gel matrix and eluted as a protein with mol.wt. 260000 and a Stokes radius of 6.8nm; it sediments at 6S in sucrose gradients. 2. Dissociation of the mammary-gland cytosol oestrogen receptor seems to be the result of interaction of the oestrogen-receptor complex with heparin. This receptor interacts with heparin covalently bound to Sepharose, thereafter sedimenting at 6S. By using this interaction, the cytosol receptor was purified 200-fold compared with the homogenate, with a yield of 70%. 3. The cytosol receptor that was not incubated or was incubated with heparin was much smaller during sucrose-gradient centrifugation than during gel filtration. This discrepancy can be explained by pressure-induced dissociation during high-speed centrifugation. This possibility is supported by the decrease in the sedimentation coefficient of the receptor with increased duration of centrifugation.

Milk protein precursors in lactating goats

1992 ◽  
Vol 1992 ◽  
pp. 2-2 ◽  
Author(s):  
B J. Bequette ◽  
C. Backwell ◽  
G.E. Lobley ◽  
J.C. MacRae
Keyword(s):  
Mammary Gland ◽  
Dietary Fat ◽  
Nutritional Value ◽  
Milk Protein ◽  
Integrated Approach ◽  
Fat Intake ◽  
Lactating Goats ◽  
Lactating Mammary Gland ◽  
Milk Component ◽  
Kinetics Of

With the failure of current nutritional schemes for dairy ruminants to predict yields of milk and milk components, and perceptions of milk's nutritional value following recommendations to reduce dietary fat intake, an integrated approach to feeding and metabolism needs to be developed. Such a system must therefore be ‘metabolite’ based.An ability to predict changes in milk constituent output in response to alterations in nutrition requires, in the first instance, the identification of specific precursors for milk component synthesis in the lactating mammary gland. Arteriovenous differences across the mammary gland indicate that blood free amino acids (AA) are either taken-up by the gland in excess, equal to, or in insufficient amounts compared to their output in milk (1). Isotope labelling experiments have indicated that, in addition to AA free in blood, the mammary gland utilises a substantial amount of AA derived from constitutive mammary gland protein breakdown (2). The present experiment was designed to investigate the AA precursors and kinetics of milk protein synthesis and to confirm and extend the latter observations.

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