PURIFICATION AND SOME PROPERTIES OF OVINE PLACENTAL LACTOGEN

1978 ◽  
Vol 78 (1) ◽  
pp. 59-69 ◽  
Author(s):  
S. REDDY ◽  
W. B. WATKINS
Keyword(s):  
Mammary Gland ◽  
Polyacrylamide Gel Electrophoresis ◽  
Ammonium Bicarbonate ◽  
Placental Lactogen ◽  
Supernatant Fraction ◽  
Major Band ◽  
Foetal Tissue ◽  
Pregnant Rabbit ◽  
Ovine Prolactin

A method has been described for the purification of ovine placental lactogen (oPL) involving the use of freshly obtained sheep foetal cotyledons. Tissue was extracted with 0·1 m-ammonium bicarbonate and the supernatant fraction, adjusted to pH 7, was brought to 60% saturation with ammonium sulphate. The resulting precipitate was then subjected to a sequence of chromatographic steps using columns of Sephadex G-100 and carboxymethylcellulose. During each stage of the purification, the lactogenic activity was monitored with a pregnant rabbit mammary gland radioreceptor assay. The yield of oPL corresponded to 8 mg/kg wet foetal tissue and the oPL possessed lactogenic activity equivalent to 1 mg ovine prolactin/mg protein and GH-like activity equivalent to 0·8 mg human GH/mg protein. The biological activity of oPL was confirmed using a rabbit intraductal mammary gland assay in vivo. After polyacrylamide gel electrophoresis at pH 8·9, oPL was resolved into one major band (isoelectric point 8·2–8·4) and four minor components, which were thought to be deamidation products of oPL. Microimmunoelectrophoresis and immunodiffusion studies confirmed that the preparation of oPL was free from serum protein contaminants.

Xanthine oxidase/dehydrogenase in mammary gland of mouse: relationship to mammogenesis and lactogenesis in vivo and in vitro

1991 ◽  
Vol 58 (4) ◽  
pp. 401-409 ◽  
Author(s):  
Thomas J. Hayden ◽  
Denise Brennan ◽  
Katherine Quirke ◽  
Paddie Murphy
Keyword(s):  
Mammary Gland ◽  
Xanthine Oxidase ◽  
Post Partum ◽  
Explant Culture ◽  
Placental Lactogen ◽  
Early Event ◽  
Histological Differentiation ◽  
Variant Enzyme

SummaryXanthine oxidase/dehydrogenase (XO/XDH) increases at mid gestation in mammary gland but not in liver of the mouse and remains elevated until the pups are weaned at 20 d post partum. The increase in enzyme activity is due neither to alteration in activators or inhibitors nor to a production of a variant enzyme with altered catalytic properties. The increase is preceded in vivo by a surge of prolactin-like activity (placental lactogen) in plasma, and prolactin is required for induction of XO/XDH in explant culture in vitro. Induction of XO/XDH in vivo and in vitro precedes the full histological differentiation of the gland. In addition, induction of XO/XDH in vitro occurs more rapidly and at lower concentrations of prolactin than does histological differentiation. Thus although XO/XDH is present in milk, increased XO/XDH activity is an early event in mammogenesis in vivo and in vitro rather than a terminal component of differentiation.

scholarly journals Regulation of milk lipid secretion: effects of oxytocin, prolactin and ionomycin on triacylglycerol release from rat mammary gland slices

1995 ◽  
Vol 308 (3) ◽  
pp. 975-981 ◽  
Author(s):  
T H M Da Costa ◽  
K Taylor ◽  
V Ilic ◽  
D H Williamson
Keyword(s):  
Mammary Gland ◽  
Protein A ◽  
Late Pregnancy ◽  
Major Effect ◽  
Milk Lipid ◽  
Hormonal Stimulation ◽  
Parathyroid Hormone Related Protein ◽  
Ovine Prolactin

A system for the study of the regulation of the release of triacylglycerols by mammary gland slices was developed. By prelabelling the triacylglycerol pool with [3H]oleate measurements of release of both mass of triacylglycerol and of newly synthesized triacylglycerol have been made. Oxytocin and ovine prolactin stimulated release of triacylglycerol and protein, but the former was 40-fold more effective. Recombinant bovine prolactin was even less active than ovine prolactin, suggesting that contamination of the latter with oxytocin and/or vasopressin was partly responsible for its stimulatory effect on release. The findings support the view that the major effect of oxytocin is to stimulate contraction of myoepithelial cells and thus release secreted lipid stored in the lumen of the mammary gland alveoli. Ionomycin, a Ca2+ ionophore, also stimulated lipid release, but probably not by the usual apocrine route. Parathyroid hormone-related protein, a peptide produced by the mammary gland, did not stimulate release or antagonize the effects of oxytocin. Release of lipid was also measured in mammary gland slices from late-pregnant, early- and mid-lactating rats and lactating rats made prolactin-deficient. Hormonal stimulation in vitro showed the maturation of response seen in vivo on transition from late pregnancy to peak lactation. Prolactin deficiency resulted in decreased release of newly synthesized lipid in response to oxytocin.

UPTAKE OF 125I-LABELLED HUMAN PLACENTAL LACTOGEN AND HUMAN PLACENTAL LACTOGEN BY THE TISSUES OF NORMAL AND LACTATING RATS

1975 ◽  
Vol 65 (2) ◽  
pp. 183-NP ◽  
Author(s):  
S. REDDY ◽  
W. B. WATKINS
Keyword(s):  
Mammary Gland ◽  
Half Life ◽  
Post Partum ◽  
Membrane Receptors ◽  
Placental Lactogen ◽  
Immunoperoxidase Technique ◽  
Human Placental Lactogen ◽  
Radioactive Label ◽  
Pregnant Rat

SUMMARY The rate of clearance from the circulation and uptake into tissues of radioactive label was studied after i.v. injection of 125I-labelled human placental lactogen (HPL) into rats at various stages of pregnancy. The half-life was obtained for the disappearance of the trichloroacetic acid-precipitable material from the plasma. The half-life, t½(S), calculated over the first 5 min after injection of the hormone was 5·4 ± 1·1 (s.d.) min, while a half-life, t½(L), of 27·9 ± 2·3 min was obtained from the decay period of 15–35 min. In the non-pregnant and pregnant rat the highest ratio of the radioactivity in an organ to that in the blood was 12–14:1 in the kidney. That the kidney is mainly involved in the uptake of exogenous HPL is further confirmed by the application of the histochemical immunoperoxidase technique. Human placental lactogen was localized in the cells of the proximal tubules of the cortex and to a lesser extent in the tubular lumen and the tubules of the medulla region. Uptake of HPL in vivo also occurs in the mammary gland tissue of the post-partum rat and reaches a maximum uptake between 15 and 30 min after injection of the hormone. Furthermore, specific uptake of HPL was observed on the alveolar cell membranes after the incubation of paraffin-embedded sections of formalin-fixed mammary gland and subsequent treatment by the peroxidase-labelled antibody method. These findings support the work of others who have demonstrated the presence of specific membrane receptors in the mammary gland for hormones with prolactin-like activity.

AN IMMUNORADIOMETRIC ASSAY (IRMA) FOR HUMANTHROMBOMODULIN

1987 ◽  
Author(s):  
J C Giddings
Keyword(s):  
Endothelial Cells ◽  
Polyclonal Antibodies ◽  
Umbilical Vein ◽  
Polyacrylamide Gel Electrophoresis ◽  
Normal Serum ◽  
Immunoradiometric Assay ◽  
Culture Dish ◽  
Major Band ◽  
Umbilical Vein Endothelial Cells

Thrombomodulin was separated from detergent-soluble fractions of human placenta using a combination of DEAE-Sepharose and thrombin-Sepharose chromatography. The final product demonstrated one major band (Mr approximately 100000) and three minor bands (Mr 40000 - 80000) on SDS-polyacrylamide gel electrophoresis. The purified protein markedly enhanced the rate of activation of human protein C by thrombin in the presence of calcium ions. Polyclonal antibodies to the isolated thrombomodulin were raised in rabbits and were shown to inhibit thrombin co-factor activity. Immunofluorescence of fibroblasts and of human umbilical vein endothelial cells in culture demonstrated that thrombomodulin antigen was specifically located in endothelial cell membranes. Affinity purified antibody was labelled with 125I and was used to establish an immunoradiometric assay (IRMA). The method was sensitive to approximately 10.0μg purified thrombomodulin per litre. The concentration of thrombomodulin in detergent-solubilised endothelial cells obtained at intervals during primary culture was proportional to the number of cells harvested for assay and appeared to reflect cell growth. Confluent cells from four experiments (approximately 2 × 106 cells per culture dish) contained on average 8.4ng thrombomodulin. Incubation of confluent endothelial cells with medium containing 1 unit per ml human α-thrombin for 10 mins at 37°C reduced the amount of cellular thrombomodulin detected in this assay by up to 30%. Assays of human plasma confirmed that low levels of thrombomodulin are present in normal circulating blood. A mean level of 160μg per litre was detected in 20 normal donors. The levels of thrombomodulin antigen in 10 normal serum were not significantly different from those in the corresponding normal plasma. Preliminary results illustrated that increased levels of thrombomodulin might be found in the plasma of some patients with a variety of clinical disorders. The data suggest that quantitative assays of thrombomodulin might provide a useful index of endothelial disturbances in vivo.

scholarly journals A panel of monoclonal antibodies to ovine placental lactogen

2000 ◽  
Vol 165 (2) ◽  
pp. 435-442 ◽  
Author(s):  
IA Forsyth ◽  
A Hutchings ◽  
GW Butcher
Keyword(s):  
Growth Hormone ◽  
Biological Activity ◽  
Monoclonal Antibodies ◽  
Mammary Gland ◽  
Antigenic Determinant ◽  
Placental Lactogen ◽  
Antigenic Determinants ◽  
Sheep Liver

A panel of 11 rat monoclonal antibodies (mAbs) has been raised to ovine placental lactogen (PL). By competitive enzyme-linked immunoabsorbent assay (ELISA), confirmed by two-site ELISA, the antibodies were shown to recognize six antigenic determinants on the ovine PL molecule, two of which overlap. One antigenic determinant (designated 1) was shared by other members of the prolactin/growth hormone (GH)/PL family in ruminants, humans and rodents. The binding of (125)I-labelled ovine PL to crude receptor preparations from sheep liver (somatotrophic) or rabbit mammary gland (lactogenic) was inhibited by mAbs recognizing antigenic determinants 2-6. Both types of receptor preparation were affected similarly. In the local in vivo pigeon crop sac assay, mAbs directed against determinants 3 and 6 enhanced the biological activity of ovine PL.

scholarly journals Purification and properties of heparin-releasable lipoprotein- associated coagulation inhibitor

Blood ◽  
1991 ◽  
Vol 78 (2) ◽  
pp. 394-400 ◽  
Author(s):  
WF Novotny ◽  
M Palmier ◽  
TC Wun ◽  
GJ Jr Broze ◽  
JP Miletich
Keyword(s):  
Vascular Endothelium ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Size Exclusion ◽  
Plasma Lipoproteins ◽  
Major Band ◽  
Coagulation Inhibitor

The lipoprotein-associated coagulation inhibitor (LACI) is present in vivo in at least three different pools: sequestered in platelets, associated with plasma lipoproteins, and released into plasma by intravenous heparin, possibly from vascular endothelium. In this study we have purified the heparin-relesable form of LACI from post-heparin plasma and show that it is structurally different from lipoprotein LACI. The purification scheme uses heparin-agarose chromatography, immunoaffinity chromatography, and size-exclusion chromatography and results in a 185,000-fold purification with a 33% yield. Heparin- releasable LACI (HRL), as analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis, under reducing conditions, appears as a major band at 40 Kd and a minor band at 36 Kd. Immunoblot analysis suggests that the 36-Kd band arises from carboxyl-terminus proteolysis that occurs during the purification. HRL has a specific activity similar to that of HepG2 or lipoprotein LACI. HRL and lipoprotein LACI combine with lipoproteins in vitro while purified HepG2 LACI does not. I125-labeled HRL, injected into a rabbit, is cleared more slowly than I125-labeled HepG2 LACI, which may be due to attachment to lipoproteins in vivo. Preliminary evidence suggests that HRL is associated with vascular endothelium, possibly by attachment to glycosaminoglycans.

scholarly journals Purification and properties of heparin-releasable lipoprotein- associated coagulation inhibitor

Blood ◽  
1991 ◽  
Vol 78 (2) ◽  
pp. 394-400 ◽  
Author(s):  
WF Novotny ◽  
M Palmier ◽  
TC Wun ◽  
GJ Jr Broze ◽  
JP Miletich
Keyword(s):  
Vascular Endothelium ◽  
Specific Activity ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Size Exclusion ◽  
Plasma Lipoproteins ◽  
Major Band ◽  
Coagulation Inhibitor

Abstract The lipoprotein-associated coagulation inhibitor (LACI) is present in vivo in at least three different pools: sequestered in platelets, associated with plasma lipoproteins, and released into plasma by intravenous heparin, possibly from vascular endothelium. In this study we have purified the heparin-relesable form of LACI from post-heparin plasma and show that it is structurally different from lipoprotein LACI. The purification scheme uses heparin-agarose chromatography, immunoaffinity chromatography, and size-exclusion chromatography and results in a 185,000-fold purification with a 33% yield. Heparin- releasable LACI (HRL), as analyzed by sodium dodecyl sulfate- polyacrylamide gel electrophoresis, under reducing conditions, appears as a major band at 40 Kd and a minor band at 36 Kd. Immunoblot analysis suggests that the 36-Kd band arises from carboxyl-terminus proteolysis that occurs during the purification. HRL has a specific activity similar to that of HepG2 or lipoprotein LACI. HRL and lipoprotein LACI combine with lipoproteins in vitro while purified HepG2 LACI does not. I125-labeled HRL, injected into a rabbit, is cleared more slowly than I125-labeled HepG2 LACI, which may be due to attachment to lipoproteins in vivo. Preliminary evidence suggests that HRL is associated with vascular endothelium, possibly by attachment to glycosaminoglycans.

STEROID METABOLISM IN THE PERFUSED HUMAN PLACENTA

1978 ◽  
Vol 87 (1) ◽  
pp. 181-191 ◽  
Author(s):  
Alfred S. Wolf ◽  
Klaus A. Musch ◽  
Werner Speidel ◽  
Jürgen R. Strecker ◽  
Christian Lauritzen
Keyword(s):  
Venous Blood ◽  
Placental Lactogen ◽  
Dehydroepiandrosterone Sulphate ◽  
Metabolic Capacity ◽  
Loading Test ◽  
Lower Range ◽  
Group I ◽  
High Concentrations ◽  
Steroid Precursor

ABSTRACT A new model for the perfusion of human term-placentas has been developed for studies on the placental biogenesis of C-18 and C-19 steroids. For viability criteria, the glucose- and oxygen-consumption, regional perfusion control by dye-infusions or scanning after injection of 99Tc-labelled macroparticles, and the histological qualification were chosen. The recycled perfusate was investigated for the steroids oestrone (Oe1), oestradiol-17β (Oe2), oestriol (Oe3), 4-androstene-3,17-dione (A), testosterone (T), and human placental lactogen (HPL) by radioimmunoassay in controls and perfusions with the foetal steroid precursor dehydroepiandrosterone sulphate (DHA-S). In control perfusions, steroid hormones were found in constant ratios (Oe1:Oe2:Oe3:T:A = 30:1.5:100:0.35:1). Following the administration of 10 mg DHA-S for testing the metabolic capacity of the organ, high concentrations of Oe1 (90–720 ng/ml = 250–3970 % as compared to 100% pre-injection values) were found, shortly preceded by a rapid increase of A (66–1000 ng/ml = 100–16 000 %). A typical surge of T (5.3–147 ng/ml = 265–4640 %) preceded the normally slower increment of Oe2 (22–220 ng/ml = 1570–4330 %). The concentrations of Oe3 and HPL remained nearly unchanged. From different steroid patterns after DHA-S-load, two distinct responses of term-placentas could be differentiated: Group I (n=12) showed high concentrations of Oe1 (3200 ± 940 %), a small increase of T (1020 ± 500%), as well as low and delayed values of Oe2 (1660 ± 450%). In Group II (n = 5), values were high for T (3160 ± 1020%) and Oe2 (3300 ± 1110%), whereas Oe1 was found in a lower range (508 ± 302%). In contrast to in vivo findings in maternal venous blood after DHS-S injection to the mother, oestrone was found in perfusions as the main oestrogen fraction from DHA-S. Thus, the analysis of such metabolic differences might be of help in the interpretation of complex results from the DHA-S-loading test.

scholarly journals Mammary gland 3D cell culture systems in farm animals

2021 ◽  
Vol 52 (1) ◽  
Author(s):  
Laurence Finot ◽  
Eric Chanat ◽  
Frederic Dessauge
Keyword(s):  
Cell Culture ◽  
Mammary Gland ◽  
Bacterial Infections ◽  
Three Dimensional ◽  
3D Cell Culture ◽  
Farm Animals ◽  
Culture Systems ◽  
Cell Culture Systems

AbstractIn vivo study of tissue or organ biology in mammals is very complex and progress is slowed by poor accessibility of samples and ethical concerns. Fortunately, however, advances in stem cell identification and culture have made it possible to derive in vitro 3D “tissues” called organoids, these three-dimensional structures partly or fully mimicking the in vivo functioning of organs. The mammary gland produces milk, the source of nutrition for newborn mammals. Milk is synthesized and secreted by the differentiated polarized mammary epithelial cells of the gland. Reconstructing in vitro a mammary-like structure mimicking the functional tissue represents a major challenge in mammary gland biology, especially for farm animals for which specific agronomic questions arise. This would greatly facilitate the study of mammary gland development, milk secretion processes and pathological effects of viral or bacterial infections at the cellular level, all with the objective of improving milk production at the animal level. With this aim, various 3D cell culture models have been developed such as mammospheres and, more recently, efforts to develop organoids in vitro have been considerable. Researchers are now starting to draw inspiration from other fields, such as bioengineering, to generate organoids that would be more physiologically relevant. In this chapter, we will discuss 3D cell culture systems as organoids and their relevance for agronomic research.

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