scholarly journals Dispersed mammary gland epithelial cells. I. Isolation and separation procedures.

1977 ◽  
Vol 72 (2) ◽  
pp. 390-405 ◽  
Author(s):  
J P Kraehenbuhl
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Connective Tissue ◽  
Structural Integrity ◽  
Plasma Cells ◽  
Buoyant Density ◽  
Light And Electron Microscopy ◽  
Enzymatic Digestion ◽  
Myoepithelial Cells ◽  
Tissue Cells

The mammary gland from midpregnant rabbits has been dissociated into individual cells by enzymatic digestion, divalent cation chelation, and gentle shearing. A heterogeneous cell population is obtained, comprising approximately 60% parenchymal cells, approximately 10% myoepithelial cells, and approximately 30% connective tissue cells, including fibroblasts, plasma cells, and microphages. The epithelial cells are characterized by the presence of fat droplets, which in 65% of the cells form large supranuclear vacuoles. Their buoyant density is less than 1.045, allowing their separation from myoepithelial cells and connective tissue cells by isopycnic centrifugation in a density gradient. The homogeneity of the epithelial cell fraction has been assessed by light and electron microscopy. The cells are viable and functionally active as indicated by their ability to exclude vital dyes, incorporate labeled precursors, consume oxygen, maintain intracellular Na+ and K+ concentrations, and retain their structural integrity. In addition, when cultured in Petri dishes, the cells grow as a monolayer, reestablish junctional complexes and retain cell polarity.

scholarly journals Distribution of myoepithelial cells and basement membrane proteins in the resting, pregnant, lactating, and involuting rat mammary gland.

1982 ◽  
Vol 30 (7) ◽  
pp. 667-676 ◽  
Author(s):  
M J Warburton ◽  
D Mitchell ◽  
E J Ormerod ◽  
P Rudland
Keyword(s):  
Mammary Gland ◽  
Membrane Proteins ◽  
Epithelial Cells ◽  
Connective Tissue ◽  
Basement Membrane ◽  
Myoepithelial Cells ◽  
Type I ◽  
Continuous Layer ◽  
Basement Membrane Proteins ◽  
Rat Mammary Gland

Using antisera to specific proteins, the localization of the rat mammary parenchymal cells (both epithelial and myoepithelial), the basement membrane, and connective tissue components has been studied during the four physiological stages of the adult rat mammary gland, viz. resting, pregnant, lactating, and involuting glands. Antisera to myosin and prekeratin were used to localize myoepithelial cells, antisera to rat milk fat globule membrane for epithelial cells, antisera to laminin and type IV collagen to delineate the basement membrane and antisera to type I collagen and fibronectin as markers for connective tissue. In the resting, virgin mammary gland, myoepithelial cells appear to form a continuous layer around the epithelial cells and are in turn surrounded by a continuous basement membrane. Antiserum to fibronectin does not delineate the basement membrane in the resting gland. The ductal system is surrounded by connective tissue. Only the basal or myoepithelial cells in the terminal end buds of neonatal animals demonstrate cytoplasmic staining for basement membrane proteins, indicating active synthesis of these proteins during this period. In the secretory alveoli of the lactating rat, the myoepithelial cells no longer appear to form a continuous layer beneath the epithelial cells and in many areas the epithelial cells appear to be in contact with the basement membrane. The basement membrane in the lactating gland is still continuous around the ducts and alveoli. In the lactating gland, fibronectin appears to be located in the basement membrane region in addition to being a component of the stroma. During involution, the alveoli collapse, and appear to be in a state of dissolution. The basement membrane is thicker and is occasionally incomplete, as also are the basket-like myoepithelial structures. Basement membrane components can also be demonstrated throughout the collapsed alveoli.

Observations on the nephridial system of the cestode Moniezia expansa (Rud., 1805)

Parasitology ◽  
1969 ◽  
Vol 59 (2) ◽  
pp. 449-459 ◽  
Author(s):  
R. E. Howells
Keyword(s):  
Electron Microscopy ◽  
Fine Structure ◽  
Epithelial Cells ◽  
Connective Tissue ◽  
Intercellular Space ◽  
Technical Assistance ◽  
Light And Electron Microscopy ◽  
Flame Cell ◽  
Research Scholarship ◽  
Research Facilities

The nephridial system of M. expansa has been studied using light and electron microscopy, and a number of histochemical techniques have been used on sections of the worm. The organization of the nephridial system and the fine structure of the flame cells and the nephridial ducts are described. Pores, which connect the nephridial lumen to the intercellular space of the connective tissue, exist at the junction of a flame cell and a nephridial duct. These pores may be considered nephrostomes and the system therefore is not protonephridial as defined by Hyman (1951).The epithelium lining the nephridial ducts has a structure which suggests that it is metabolically active. It is postulated that the beating of the cilia of the flame cells draws fluid into the ducts via the nephrostomes, with absorption and/or secretion of solutes being carried out by the epithelial cells of the duct walls. The function of the nephridial system is discussed.I am grateful to Professor James Brough for the provision of research facilities at the Department of Zoology, University College, Cardiff, andtoDrD. A. Erasmus for much helpful advice during the course of the work. I wish to thank Professors W. Peters and T. Wilson for critically reading the manuscript and Miss M. Williams and Mr T. Davies for expert technical assistance.I also wish to thank the Veterinary Inspector and his staff at the Roath Abattoir, Cardiff, for their kind co-operation and assistance in obtaining material.The work was carried out under the tenure of an S.R.C. research scholarship.

Innervation of vibrissa follicles in the marsupial Trichosurus vulpecula

1974 ◽  
Vol 22 (3) ◽  
pp. 263 ◽  
Author(s):  
DE Hollis ◽  
AG Lyne
Keyword(s):  
Epithelial Cells ◽  
Connective Tissue ◽  
Outer Layer ◽  
Light And Electron Microscopy ◽  
Sensory Receptor ◽  
Merkel Cell ◽  
Myelinated Nerves ◽  
Sensory Receptor Cells ◽  
A Chain ◽  
Connective Tissue Sheath

The innervation of the mystacial vibrissa follicles in the adult brush-tailed possum, T. vulpecula, has been studied by light and electron microscopy. One to five large nerve trunks penetrate the lower part of the follicle capsule and divide many times as they ascend and completely envelop the con- nective tissue sheath of the follicle. As many as 500 myelinated nerves have been observed in the mid region of the largest follicles. Above the mid region, most of the nerves move closer to the centre of the follicle and finally terminate within or near the outer layer of epithelial cells. Four main types of nerve endings have been observed: (1) Sensory receptor cells, called Merkel cells, with their associated neurites are numerous within the outer layer of epithelial cells. (2) Palisade endings, which are less common than the Merkel cell-neurite complexes, surround the upper part of the glassy membrane of the follicle. In transverse section each palisade ending appears as a flattened central neurite partially enveloped on either side by Schwann cell processes. (3) Bulbous endings occur in both the connective tissue sheath and in the outer layer of follicle epithelial cells. They are larger than types (1) and (2) and their ultrastructure varies markedly. (4) Compound endings occur within the connective tissue sheath of the follicle. They are uncommon but large and are composed of a chain of bulbous units joined by nerves; the entire ending may be encapsulated. Within each unit there is a tangle of nerve fibres. The Merkel cell-neurite complexes and the palisade endings in T. vulpecula are remarkably similar to those of eutherian mammals, suggesting that such sensory structures were features of primitive mammals.

Complex mammary tumours in the female dog: a review

2005 ◽  
Vol 72 (S1) ◽  
pp. 90-97 ◽  
Author(s):  
Eva Hellmén
Keyword(s):  
Mammary Gland ◽  
Growth Factors ◽  
Epithelial Cells ◽  
Sex Hormones ◽  
Myoepithelial Cells ◽  
The Body ◽  
Pronounced Effect ◽  
Mammary Tumours ◽  
Luminal Epithelial Cells

Spontaneous mammary tumours are most frequently seen (apart from rodents) in women, female dogs and cats. The mammary gland is the most commonly affected organ for tumours in women and in female dogs. The mammary gland has a similar histology in the different species whereas the number of glands differs as well as the number of interlobular ducts that reach the nipple/teat. The parenchymatous tissue is composed of alveoli that turn into interlobular ducts. The whole ductal tree is outlined by a two-layered epithelium with the luminal epithelial cells adjacent to the lumen and the more sparse myoepithelial cells peripherally located to these. Different proteins such as growth factors regulate the mammary gland, as they do for all tissues in the body. In addition, sex hormones regulate the biology of the mammary gland. Oestrogen has the most pronounced effect on duct growth whereas progesterone promotes growth of the alveoli.

A new monoclonal antibody to a cell-surface antigen that distinguishes luminal epithelial and myoepithelial cells in the rat mammary gland

1989 ◽  
Vol 94 (3) ◽  
pp. 545-552
Author(s):  
R.S. Mahendran ◽  
M.J. O'Hare ◽  
M.G. Ormerod ◽  
P.A. Edwards ◽  
R.A. McIlhinney ◽  
...  
Keyword(s):  
Monoclonal Antibody ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Milk Fat ◽  
Single Cells ◽  
Myoepithelial Cells ◽  
Stages Of Development ◽  
Leukaemia Cell Line ◽  
Flow Cytometric ◽  
Rat Mammary Gland

A monoclonal antibody (25.5) has been produced that recognises luminal epithelial cells of the rat mammary gland. This antibody together with monoclonal anti-CALLA antibodies, which react with mammary myoepithelial cells, has been used in biochemical, immunocytochemical and flow cytometric studies. Antibody 25.5 bound to proteins of molecular weight 70K and 25K (K = 10(3) Mr) in both the rat milk fat globule membrane and in single cell suspensions prepared from the virgin adult rat mammary gland. Anti-CALLA antibody (J5), recognised a 93–100K protein in the gland extracts, which co-electrophoresed with the CALLA/CD-10 antigen from NALM-6 acute lymphoblastic leukaemia cell line. Antibody 25.5 bound to the luminal surface of rat mammary epithelial cells at all stages of development from neonatal through to pregnancy, lactation and involution. CALLA immunoreactive staining has previously been shown on basally located presumptive myoepithelial cells at all stages of development. Flow cytometric analyses demonstrated that 25.5 and anti-CALLA antibodies stained independent cell populations in suspensions of single cells prepared from purified epithelial elements from the mammary gland of adult virgin rat.

scholarly journals Dissociation of cytological and functional differential in virgin mouse mammary gland during inhibition of DNA synthesis

1982 ◽  
Vol 53 (1) ◽  
pp. 97-114 ◽  
Author(s):  
B.K. Vonderhaar ◽  
G.H. Smith
Keyword(s):  
Mammary Gland ◽  
Epithelial Cells ◽  
Dna Synthesis ◽  
Milk Protein ◽  
Light And Electron Microscopy ◽  
Mouse Mammary Gland ◽  
Enhanced Production ◽  
Virgin Mouse ◽  
In Cells

Epithelial cells in mammary gland explants from mice assume a secretory appearance and synthesize the milk proteins, casein and alpha-lactalbumin, when cultured in the presence of insulin, hydrocortisone and prolactin. In cells from the glands of mature virgin animals such syntheses are known to require DNA synthesis. Addition of cytosine-beta-D-arabinofuranoside to the explant cultures suppresses both hormonally induced DNA synthesis and enhanced production of milk protein. To determine the level at which this block in terminal differentiation occurs, epithelial cell pellets were prepared from virgin mouse mammary gland explants cultured with various combination of insulin, hydrocortisone and prolactin, and subsequently examined by light and electron microscopy. We observed that the epithelial cells cultured in the presence of all three hormones developed fully, cytologically and ultrastructurally, even in the absence of DNA synthesis in vitro. Likewise, these cells were able to incorporate [3H]uridine into RNA efficiently and to incorporate amino acids into acid-precipitable polypeptides at levels equivalent to the untreated controls. However, immunoprecipitation of newly synthesized casein peptides showed that no new synthesis of casein occurred in cells prevented from synthesizing DNA. These data show uncoupling of cytological development and synthesis of milk protein in mammary explants from mature virgin mice inhibited from synthesizing DNA.

scholarly journals Morphological and ultrastructural aspects of the cyclical changes of human mammary gland during the menstrual cycle

1994 ◽  
Vol 112 (2) ◽  
pp. 543-547 ◽  
Author(s):  
Afonso Celso Pinto Nazário ◽  
Manuel de Jesus Simões ◽  
Geraldo Rodrigues de Lima
Keyword(s):  
Mammary Gland ◽  
Menstrual Cycle ◽  
Epithelial Cells ◽  
Connective Tissue ◽  
Great Majority ◽  
Mammary Tissue ◽  
Secretory Phase ◽  
Proliferative Phase ◽  
Human Mammary Gland ◽  
Mitotic Figures

Analyzing the morphological and ultrastructural features of the mammary gland during the menstrual cycle, the authors observed that in the proliferative phase, the mammary gland consisted of few developed lobules and presented a relative absence of mitotic figures. In this phase, the great majority of the epithelial cells contained small, dark, irregular, rich heterochromatinic nuclei. The mammary stroma showed similar findings, presenting dense connective tissue with few enhanced fibroblasts. During the secretory phase, the lobules were well developed and mitotic figures were usually observed. In this phase, the great majority of the ephitelial cells presented clear voluminous, rich euchromatinic nuclei; the stroma consisted of fibroblasts with voluminous nuclei full of euchromatin. There are evident modifications of the mammary tissue according to the phase of the menstrual cycle. The morphological and ultrastructural modifications indicate higher metabolical and mitotic activities during the secretory phase.

scholarly journals Acid Mucopolysaccharides in Mammary Tumors of Dogs

1979 ◽  
Vol 16 (5) ◽  
pp. 493-509 ◽  
Author(s):  
T. E. Palmer ◽  
A. W. Monlux
Keyword(s):  
Hyaluronic Acid ◽  
Epithelial Cells ◽  
Connective Tissue ◽  
Hyaline Cartilage ◽  
Mammary Tumors ◽  
Myoepithelial Cells ◽  
Fibrous Connective Tissue ◽  
Intercellular Matrix ◽  
Acid Mucopolysaccharides ◽  
Mesodermal Origin

The predominant acid mucopolysaccharides found in selected epithelial mammary tumors of dogs stained with alcian blue and were labile to hyaluronidase digestion. These histochemical characteristics identified them as hyaluronic acid, chondroitin-4- and chondroitin-6-sulfate. The intensity of the staining of these acid mucopolysaccharides varied in a transitionary process from a precartilaginous to a pseudocartilaginous intercellular matrix to mature hyaline cartilage. The tumor acid mucopolysaccharides were indistinguishable from those associated with formation of cartilage in developing mammals; such cartilage is reported to be produced only by cells of mesodermal origin. There was no evidence to suggest transitional changes in myoepithelial cells, neoplastic epithelial cells or their components that could contribute to the formation of the acid mucopolysaccharides. It was concluded that the heterotopic tissues (cartilage, bone and fibrous connective tissue) in the epithelial mammary tumors were derived from cells of mesodermal orgin and formed the adjacent stroma in areas of neoplasia.

A HISTOLOGICAL AND FUNCTIONAL STUDY OF THE MAMMARY GLAND IN NORMAL AND AGALACTIC SOWS

1958 ◽  
Vol 17 (1) ◽  
pp. 63-NP ◽  
Author(s):  
B. A. CROSS ◽  
R. F. W. GOODWIN ◽  
I. A. SILVER
Keyword(s):  
Alkaline Phosphatase ◽  
Mammary Gland ◽  
Epithelial Cells ◽  
Dose Response ◽  
Myoepithelial Cells ◽  
Functional Study ◽  
Milk Ejection ◽  
Histological Changes ◽  
Alveolar Structure ◽  
Clinical Cases

SUMMARY 1. A method has been devised for obtaining repeated biopsy samples from the mammaryglands of sows, and by its use the histological changes associated with farrowing have been studied. 2. Before farrowing, the alveoli were at first small and filled with a hyaline eosinophilic secretion. Progressive distension of the alveoli followed, accompanied by a gradual replacement of the eosinophilic material by basophilic secretion and the onset of fat secretion. At farrowing the alveoli were contracted and their contents evacuated. 3. Acute involutional changes seen in the engorged glands of early-weaned animals, or animals that were suckled with one teat occluded, were characterized by solidification of the alveoli, swollen degenerating epithelial cells and, later, stromal proliferation. Little alveolar structure remained after 8 days. 4. Descriptions are given of three main types of mammary defect that were detected histologically in clinical cases of agalactia. 5. In experiments on milk ejection, recorded manometrically, the dose-response relation to injected oxytocin was determined. Two out of three sows responded to 10 mu. and maximal responses were obtained with doses of 200–500 mu. 6. The occurrence of myoepithelial cells in the sow's mammary gland has been demonstrated by the alkaline phosphatase technique.

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