Ultrasonographic assessment of the feline mammary gland

2008 ◽  
Vol 10 (5) ◽  
pp. 466-471 ◽  
Author(s):  
Rita Payan-Carreira ◽  
Ana C. Martins-Bessa
Keyword(s):  
Mammary Gland ◽  
Diagnostic Tool ◽  
Late Pregnancy ◽  
Mammary Glands ◽  
Mammary Tissue ◽  
Physiological Changes ◽  
Linear Transducer ◽  
Pregnancy And Lactation ◽  
Ultrasonographic Assessment ◽  
Ultrasonographic Appearance

The aim of this study is to characterise the feline mammary echotexture using B-mode ultrasonography, which is not routinely used to examine the feline mammary gland. Using a 5–9 MHz linear transducer the ultrasonographic appearance of non-stimulated and stimulated mammary glands was determined in 35 mature intact non-pregnant, pregnant and lactating queens aged from 16 months to 8 years. In intact non-pregnant queens, mammary glands are fairly underdeveloped and on the ultrasonograms they appear with a regular hypoechoic texture and generally show a thickness of less than 2.0 mm. The stimulated mammary tissue typically presents a more hyperechoic appearance compared to the non-stimulated gland and a fine granular echotexture. Maximum echogenicity of the mammary gland is reached during lactation. In late pregnancy, the mammary glands reach 6–9 mm in thickness. During lactation, the size of the glands depends on the existence of a suckling stimulus, with the suckled glands reaching about 11 mm in thickness. Ductal structures can only be imaged during late pregnancy and lactation. Ultrasonographic evaluation of the feline mammary gland can become a valuable diagnostic tool to characterise physiological changes and may further contribute to a better characterisation of diseased mammary tissue.

scholarly journals Identification of reference genes for RT-qPCR in ovine mammary tissue during late pregnancy and lactation and in response to maternal nutritional programming

2014 ◽  
Vol 46 (15) ◽  
pp. 560-570 ◽  
Author(s):  
A. M. Paten ◽  
S. J. Pain ◽  
S. W. Peterson ◽  
H. T. Blair ◽  
P. R. Kenyon ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Reference Genes ◽  
Physiological State ◽  
Late Pregnancy ◽  
Mammary Tissue ◽  
Qpcr Data ◽  
Maternal Programming ◽  
Pregnancy And Lactation ◽  
Measure Gene Expression

The mammary gland is a complex tissue consisting of multiple cell types which, over the lifetime of an animal, go through repeated cycles of development associated with pregnancy, lactation and involution. The mammary gland is also known to be sensitive to maternal programming by environmental stimuli such as nutrition. The molecular basis of these adaptations is of significant interest, but requires robust methods to measure gene expression. Reverse-transcription quantitative PCR (RT-qPCR) is commonly used to measure gene expression, and is currently the method of choice for validating genome-wide expression studies. RT-qPCR requires the selection of reference genes that are stably expressed over physiological states and treatments. In this study we identify suitable reference genes to normalize RT-qPCR data for the ovine mammary gland in two physiological states; late pregnancy and lactation. Biopsies were collected from offspring of ewes that had been subjected to different nutritional paradigms during pregnancy to examine effects of maternal programming on the mammary gland of the offspring. We evaluated eight candidate reference genes and found that two reference genes ( PRPF3 and CUL1) are required for normalising RT-qPCR data from pooled RNA samples, but five reference genes are required for analyzing gene expression in individual animals ( SENP2, EIF6, MRPL39, ATP1A1, CUL1). Using these stable reference genes, we showed that TET1, a key regulator of DNA methylation, is responsive to maternal programming and physiological state. The identification of these novel reference genes will be of utility to future studies of gene expression in the ovine mammary gland.

scholarly journals Regulation of lipogenic capacity in lactating rats

1982 ◽  
Vol 208 (3) ◽  
pp. 611-618 ◽  
Author(s):  
M R Grigor ◽  
A Geursen ◽  
M J Sneyd ◽  
S M Warren
Keyword(s):  
Mammary Gland ◽  
Fatty Acid ◽  
Malic Enzyme ◽  
Fatty Acid Synthase ◽  
Specific Activity ◽  
Mammary Glands ◽  
Lipogenic Enzymes ◽  
Pregnancy And Lactation ◽  
Specific Activities

1. The rate of mammary-gland lipogenesis measured in vivo from 3H2O was suppressed after decreasing the milk demand by decreasing the number of pups from ten to two or three, as well as by giving diets containing lipid [Grigor & Warren (1980) Biochem. J. 188, 61-65]. 2. The specific activities of the lipogenic enzymes fatty acid synthase, glucose 6-phosphate dehydrogenase and ‘malic’ enzyme increased between 6- and 10-fold in the mammary gland and between 2- and 3-fold in the livers during the first 10 days of lactation. The increases in specific activity coupled with the doubling of liver mass which occurred during pregnancy and lactation resulted in considerable differences in total liver activities when compared with virgin animals. 3. Although consumption of a diet containing 20% peanut oil suppressed the activities of the three lipogenic enzymes in the livers, only the ‘malic’ enzyme was affected in the mammary glands. 4. In contrast, decreased milk demand did not affect the specific activities of any of the liver enzymes, whereas it resulted in suppression of all three lipogenic enzymes of the mammary glands. There was no effect on either the cytoplasmic malate dehydrogenase or the lactate dehydrogenase of the mammary gland. 5. In all the experiments performed, the activity of the fatty acid synthase correlated with the amount of material precipitated by the rabbit antibody raised against rat fatty acid synthase.

ANALYSIS OF RIBOSOMES AND POLYSOMES DERIVED FROM RABBIT MAMMARY GLANDS DURING PREGNANCY AND LACTATION

1971 ◽  
Vol 49 (4) ◽  
pp. 667-NP ◽  
Author(s):  
I. D. HERRIMAN ◽  
G. D. BAIRD ◽  
JUDY M. BRUCE
Keyword(s):  
Electron Microscopy ◽  
Density Gradient ◽  
Gradient Analysis ◽  
Late Pregnancy ◽  
Sucrose Density Gradient ◽  
Mammary Glands ◽  
Pregnancy And Lactation

SUMMARY Whole-ribosome and polysome-enriched fractions were prepared from the mammary glands of rabbits during late pregnancy and lactation. The composition of the fractions was determined by sucrose density gradient analysis and electron microscopy. The range of size of polysomal aggregates was similar in the late-pregnant and lactating gland, with aggregates containing five to nine ribosomal units predominating. However, the amount of polysomes relative to monosomes was invariably found to increase after parturition. The greater portion of this increase was accounted for by the increased abundance of aggregates containing five to nine units.

Mammary gland cell content during various phases of lactation

1962 ◽  
Vol 203 (5) ◽  
pp. 939-941 ◽  
Author(s):  
Richard C. Moon
Keyword(s):  
Mammary Gland ◽  
Deoxyribonucleic Acid ◽  
Cellular Proliferation ◽  
Gland Cell ◽  
Late Pregnancy ◽  
Mammary Glands ◽  
Lactation Period ◽  
Cell Content ◽  
Rat Mammary Gland ◽  
Mammary Gland Cell

Deoxyribonucleic acid (DNA) was used as an index of the cellular state of the rat mammary gland in late pregnancy ( day 20) and early ( day 1), intense ( day 14), and declining ( day 28) lactation. Dams sacrificed on day 28 of lactation were provided with foster litters on day 14 postpartum to insure a strong sucking stimulus during the lactation period from days 14–28. Mammary DNA increased 57% from day 20 of pregnancy to lactation day 14, but no significant change in DNA content was evident by day 1 of lactation. A significantly lower DNA concentration was observed in mammary glands of rats sacrificed at lactation day 28 when compared with that of animals killed at day 14 of lactation. The data suggest that cellular proliferation of mammary gland continues well into lactation and that a decline in lactation may be due, in part, to a reduction in the number of milk-secreting cells.

scholarly journals Has the mammary gland a protective mechanism against overexposure to triiodothyronine during the peripartum period? The prolactin pulse down-regulates mammary type I deiodinase responsiveness to norepinephrine

2004 ◽  
Vol 183 (2) ◽  
pp. 267-277 ◽  
Author(s):  
B Anguiano ◽  
R Rojas-Huidobro ◽  
G Delgado ◽  
C Aceves
Keyword(s):  
Mammary Gland ◽  
Critical Role ◽  
Alveolar Epithelium ◽  
Late Pregnancy ◽  
Protective Mechanism ◽  
Type I ◽  
Key Factor ◽  
Pregnancy And Lactation ◽  
Contrary Effect ◽  
Peripartum Period

Peripartum is a crucial period for mammary gland final differentiation and the onset of lactation. Although the ‘trigger’ for lactogenesis depends on several hormones, a key factor is the peripartum prolactin (PRL) pulse whose deletion results in a failure to initiate milk production. Other hormones having a critical role during this period but exerting a contrary effect are the thyronines. A transitory hypothyroidism occurs at peripartum in serum and several other extrathyroidal tissues, whereas the induction of hyperthyroidism during late pregnancy is associated with the absence of lactation after delivery. We analyzed the mammary gland during pregnancy and lactation for: (a) the type and amount of thyroid receptors (TRs), (b) the local triiodothyronine (T3) generation catalyzed by type I deiodinase (Dio1), (c) the Dio1 response to norepinephrine (NE) and (d) the effect on Dio1 and TRs of blocking the PRL pulse at peripartum. Our data showed that during pregnancy the mammary gland contains Dio1 in low amounts associated with the highest expression of TRα1; whereas during lactation the gland shows high levels of both Dio1 and TRα1. However, at peripartum, both TRs and Dio1 decrease, and Dio1 becomes refractory to NE. This refractoriness disappears when the PRL pulse is blocked by the dopamine agonist bromocriptine. This blockade is also accompanied by a significant decrease in cyclin D1 expression. Our data suggested that the peripartum PRL pulse is part of a protective mechanism against precocious differentiation and/or premature involution of the alveolar epithelium due to T3 overexposure.

XXIV.—The Innervation of the Human Quiescent Nipple, with Notes on Pigmentation, Erection, and Hyperneury

1949 ◽  
Vol 61 (3) ◽  
pp. 699-717 ◽  
Author(s):  
E. P. Cathcart ◽  
F. W. Gairns ◽  
H. S. D. Garven
Keyword(s):  
Mammary Gland ◽  
Considerable Change ◽  
The Other ◽  
Mammary Tissue ◽  
Histological Structure ◽  
Nerve Fibres ◽  
Histological Studies ◽  
Pregnancy And Lactation ◽  
To Receive ◽  
Stimulation Of

It has been known from antiquity that involution of the uterus is aided by putting the child to the breast, and the work of Moir (1933) has demonstrated conclusively that suckling brings about waves of contraction of the puerperal uterus. Since suckling must necessarily involve stimulation of the nipple, it seemed of interest to know what sensory apparatus is present in the nipple to receive these stimuli. While histological studies of the mammary gland itself have been numerous, only slight attention has been paid to the histological structure of the areola and the nipple.It must be appreciated from the outset that the present study is devoted to the innervation of the nipple in the quiescent breast. There may be considerable change during pregnancy and lactation, not only in the size of the organ and its epithelium but also in the other structures. It has been shown that there is an increase in the number of nerve-fibres in the actively secreting mammary tissue, and it is possible that there is an increase in the nerve-structures of the nipple also. The richness of the innervation in the quiescent nipple certainly makes a further study of these nerve-structures during pregnancy and lactation of great interest.

scholarly journals Essential functions of p21-activated kinase 1 in morphogenesis and differentiation of mammary glands

2003 ◽  
Vol 161 (3) ◽  
pp. 583-592 ◽  
Author(s):  
Rui-An Wang ◽  
Ratna K. Vadlamudi ◽  
Rozita Bagheri-Yarmand ◽  
Iwan Beuvink ◽  
Nancy E. Hynes ◽  
...  
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Mammary Gland Development ◽  
Mammary Epithelial Cells ◽  
Ectopic Expression ◽  
Functional Differentiation ◽  
Mammary Glands ◽  
Pregnancy And Lactation ◽  
P21 Activated Kinase ◽  
Gland Development

Although growth factors have been shown to influence mammary gland development, the nature of downstream effectors remains elusive. In this study, we show that the expression of p21-activated kinase (Pak)1, a serine/threonine protein kinase, is activated in mammary glands during pregnancy and lactation. By targeting an ectopic expression of a kinase-dead Pak1 mutant under the control of ovine β-lactoglobulin promoter, we found that the mammary glands of female mice expressing kinase-dead Pak1 transgene revealed incomplete lobuloalveolar development and impaired functional differentiation. The expression of whey acidic protein and β-casein and the amount of activated Stat5 in the nuclei of epithelial cells in transgenic mice were drastically reduced. Further analysis of the underlying mechanisms revealed that Pak1 stimulated β-casein promoter activity in normal mouse mammary epithelial cells and also cooperated with Stat5a. Pak1 directly interacted with and phosphorylated Stat5a at Ser 779, and both COOH-terminal deletion containing Ser 779 of Stat5a and the Ser 779 to Ala mutation completely prevented the ability of Pak1 to stimulate β-casein promoter. Mammary glands expressing inactive Pak1 exhibited a reduction of Stat5a Ser 779 phosphorylation. These findings suggest that Pak1 is required for alveolar morphogenesis and lactation function, and thus, identify novel functions of Pak1 in the mammary gland development.

Nuclear targeting of stanniocalcin to mammary gland alveolar cells during pregnancy and lactation

2005 ◽  
Vol 289 (4) ◽  
pp. E634-E642 ◽  
Author(s):  
Craig P. Hasilo ◽  
Christopher R. McCudden ◽  
J. Ryan J. Gillespie ◽  
Kathi A. James ◽  
Edward R. Hirvi ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mammary Gland ◽  
Molecular Mass ◽  
Chemical Reduction ◽  
Mammary Tissue ◽  
Nuclear Targeting ◽  
Alveolar Cells ◽  
Hormone Production ◽  
Pregnant Rats ◽  
Pregnancy And Lactation

In most mammalian tissues, the stanniocalcin-1 gene (STC-1) produces a 50-kDa polypeptide hormone known as STC50. Within the ovaries, however, the STC-1 gene generates three higher-molecular-mass variants known as big STC. Big STC is targeted locally to corpus luteal cells to block progesterone release. During pregnancy and lactation, however, ovarian big STC production increases markedly, and the hormone is released into the serum. During lactation, this increase in hormone production is dependent on a suckling stimulus, suggesting that ovarian big STC may have regulatory effects on the lactating mammary gland. In this report, we have addressed this possibility. Our results revealed that virgin mammary tissue contained large numbers of membrane- and mitochondrial-associated STC receptors. However, as pregnancy progressed into lactation, there was a decline in receptor densities on both organelles and a corresponding rise in nuclear receptor density, most of which were on milk-producing, alveolar cells. This was accompanied by nuclear sequestration of the ligand. Sequestered STC resolved as one ∼135-kDa band in the native state and therefore had the appearance of a big STC variant. However, chemical reduction collapsed this one band into six closely spaced, lower-molecular-mass species (28–41 kDa). Mammary gland STC production also underwent a dramatic shift during pregnancy and lactation. High levels of STC gene expression were observed in mammary tissue from virgin and pregnant rats. However, gene expression then fell to nearly undetectable levels during lactation, coinciding with the rise in nuclear targeting. These findings have thus shown that the mammary glands are indeed targeted by STC, even in the virgin state. They have further shown that there are marked changes in this targeting pathway during pregnancy and lactation, accompanied by a switch in ligand source (endogenous to exogenous). They also represent the first example of nuclear targeting by STC.

Ruminants express a prolactin receptor of Mr 33 000—36 000 in the mammary gland throughout pregnancy and lactation

1993 ◽  
Vol 139 (1) ◽  
pp. 37-49 ◽  
Author(s):  
J. J. Smith ◽  
A. V. Capuco ◽  
I. H. Mather ◽  
B. K. Vonderhaar
Keyword(s):  
Mammary Gland ◽  
Developmental Stages ◽  
Developmental Regulation ◽  
Prolactin Receptor ◽  
Binding Activity ◽  
Receptor Type ◽  
Mammary Tissue ◽  
Cross Linking ◽  
Developmental Variation ◽  
Pregnancy And Lactation

ABSTRACT Developmental variation in the expression of the prolactin receptor in the ruminant mammary gland was investigated. Affinity chromatography revealed that bovine prolactin and human GH each bound to the same mammary gland proteins, yielding fractions enriched in binding activity and a protein of Mr 36 000, assumed to be a bovine prolactin receptor. Affinity cross-linking of 125I-labelled human GH to mammary microsomes confirmed that the Mr 36 000 protein was a bovine prolactin receptor. Binding assays of receptors in microsomes from the mammary tissue of cows and ewes at various stages of the lactational/reproductive cycle indicated developmental regulation of receptor concentration, but not receptor type, as no other bovine prolactin receptor type was detected by affinity cross-linking. These results suggest that differences in the response to prolactin in the mammary gland at various developmental stages in ruminants are not due to the expression of different forms of the prolactin receptor, and the lack of a prolactin effect on established lactation in ruminants is not due to the absence of the Mr 36 000 form of the prolactin receptor. Journal of Endocrinology (1993) 139, 37–49

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