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PubMed1980

The placenta in intrauterine fetal deprivation. II. Biochemical profile of placentas from deliveries associated with fetal distress.

The activity of enzymes with a regulatory function in the pathways of glycolysis, glyconeogenesis and NADP-generation, and the tissue content of DNA, protein, glycogen, triglycerides (TG), phospholipids (PL), cholesterol and dry matter were investigated in placentas from deliveries accompanied by fetal distress as a result of umbilical cord compression or placental dysfunction in toxemic pregnancies. In placentas from cases of fetal distress due to umbilical cord compression, there was increased activity of pyruvate kinase, 6-phosphogluconate dehydrogenase and NADP-malate dehydrogenase, and decreased activity of phosphoenolpyruvate carboxylase. The activity of aspartate aminotransferase was unchanged, and that of glucose-6-phosphate dehydrogenase was slightly elevated. The tissue content of dry matter, DNA, TG and PL was increased, whereas the protein, cholesterol and glycogen concentrations remained unaltered. In placentas from deliveries accompanied by fetal distress due to placental dysfunction, pyruvate kinase, when calculated per mg protein, was the only enzyme with decreased activity. TG, PL, glycogen and dry matter content were increased, DNA concentration was decreased, and protein and cholesterol remained unchanged. It is suggested that the divergent placental metabolic patterns found in the two fetal distress groups are related to the different levels of disturbed oxygen passage along the uterus-placenta-fetus axis.

Female↗
PubMed1993

A heparin-binding form of placenta growth factor (PlGF-2) is expressed in human umbilical vein endothelial cells and in placenta.

Placenta Growth Factor (PlGF) was recently discovered as a secreted growth factor for vascular endothelial cells and based on its homology to vascular endothelial growth factor (VEGF), can be classified as a new member of this growth factor family. We have carried out polymerase chain amplification (PCR) of RNA from human umbilical vein endothelial cells and placenta tissue and discovered a second species of PlGF, PlGF-2. PlGF-2 has a 21-amino acid insertion not present in PlGF-1 coding for a highly basic region near the C-terminus. This is similar to VEGF189. Northern analysis has shown, that the PlGF gene is expressed only in a limited number of cell types and tissues, e.g. human umbilical vein endothelial cells (HUVE) and placenta. Infection of Sf158 insect cells with recombinant baculoviruses specific for the two forms showed, that both, PlGF-1 and PlGF-2 are secreted efficiently into the supernatant and PlGF-2 can bind with high affinity to heparin. Both PlGF forms had a similar mitogenic potency for bovine aortic endothelial cells. Binding studies with 125I-VEGF165 demonstrate, that supernatant of PlGF expressing insect cells can compete for receptor binding. Similar to VEGF, PlGF can exist in different forms which are probably generated by differential splicing. The occurrence of two molecular forms of this endothelial specific growth factor suggests different physiological roles of the two forms during placental development and differentiation.

Amino Acid Sequence↗
PubMed1991

[Pathology of the placenta. VI. Circulation disorders of the placenta. Maternal circulation (intervillous space)].

Disorders of intervillous circulation are covered in this sixth part of the account of Pathology of the Placenta. Proposed in this paper are a new setup and modified nomenclature in which the term of "infarction" is definitely abandoned, as there can be neither genuinely anaemic nor haemorrhagic infarction in the placenta. Alterations which we consider as a formally pathogenetic chain are discussed by the order of focus of villous collapse, reticular intervillous fibrin deposition, and chronic disorder of intervillous circulation. These should be distinguished from subchorionic fibrin deposition, a special case of chronic circulatory disorder. Reference is finally made to intervillous haemorrhage and retroplacental haemorrhage (premature detachment of the placenta). An attempt is made, in conclusion, to give an account of the causative genesis of impairment to intervillous circulation together with various pathologic-anatomic findings recordable from myometrial and decidual arteries.

Arteries↗
PubMed1991

[Pathology of the placenta. VII, Inflammation of the placenta].

A general account of routes of infection is followed by reference to localisations of placental infection. The most common routes of infection are transmembrane, transdecidual, haematogenico-maternal, and haematogenico-foetal. Intra-uterine infections with placental involvement may be caused by several types of pathogens, with particular reference being made to listeriosis, tuberculosis, and lues, while virus infections may be associated with rubella and cytomegaly and protozoonosis with toxoplasmosis. Unambiguous morphological traces are left in the placenta merely by few of these "specific" infections. A possible pathogen, therefore, can be rarely concluded from the type of inflammatory placental involvement. Reference is also made to "villitis of unknown aetiology", an aetiologically obscure, probably haematogenico-maternal infection of the placenta. Introduction of this term to histological routine diagnosis is recommended. This account of placental inflammation is completed by explanations on relationships between inflammation and impaired maturation of the placenta as well as between inflammation and intervillous fibrin deposition or chronic disorders of intervillous circulation.

Female↗
PubMed1978

Studies of beta-glucuronidase in first-trimester placenta, term placenta and hydatidiform mole.

The specific activity and isoenzyme pattern of beta-glucuronidase (beta-D-glucuronide glucurononosohydrolase, EC 3.2.1.31) from first-trimester placenta, term placenta and hydatidiform mole were compared. Enzyme activity is highest in term placenta and lowest in hydatidiform mole, reflecting the steroid conjugation requirements of the tissues. The difference in enzyme activity is due to variation in the level of one isoenzyme form (isoenzyme B) of beta-glucuronidase, which is absent in molar tissue. The possible cause for the changing isoenzyme pattern is discussed.

Female↗
PubMed1992

Determination of concentrations of adenosine and other purines in human term placenta by reversed-phase high-performance liquid chromatography with photodiode-array detection: evidence for pathways of purine metabolism in the placenta.

A robust analytical method, using reversed-phase high-performance liquid chromatography with gradient elution and photodiode-array detection, was used to measure six purines and beta-NAD+ in acid-soluble extracts of samples taken from six different regions of human term placenta. Resolution of the analyte peaks in chromatographic profiles of the extracts, and the use of optimized integration, allowed simultaneous quantitation of all seven analytes from a single chromatogram. Peak purity was confirmed via on-line analysis of peak spectra, utilizing the purity parameter treatment of spectral data. Major placental purines were adenosine, inosine, hypoxanthine and adenine. Except for adenine, concentrations of the purines varied by two-fold or more between different regions of each placenta, but concentration ratios, i.e., adenosine/inosine and inosine/hypoxanthine, were similar. The findings indicate that the pathway of ATP breakdown to hypoxanthine in ischemic human term placenta is via adenosine, and that regional differences in placental concentrations of adenosine and its metabolites may result from regional differences in degree of ischemia.

Adenosine↗
PubMedDate not supplied

Fluid shift across the placenta: I. The effect of dextran T 40 in the isolated guinea-pig placenta.

In an effort to understand better the transplacental water flux induced by osmotic forces, 17 near-term guinea-pig placentae were perfused on both sides with an artificial cell-free fluid containing dextran. Maternal and fetal arterial inflow rates were kept constant by syringe pumps and inflow and outflow pressures were recorded continuously. Precise measurements of outflow rates were made by weight determination and transplacental fluid shifts calculated by weight changes during placental passage. The content of dextran T 40 in the perfusion fluid was altered in stepwise manner from 0 to 60 to 120 g/l, and the effects of all possible combinations of fetal--maternal concentration differences on the transplacental fluid shift were observed. On the average, about 1 X 10(-3) ml/min/g placenta was moved per 1 g/l concentration difference. In two experiments venous colloid osmotic pressures were recorded continuously. In ten experiments the oncotic fluid shift was counterbalanced by an additional hydrostatic pressure difference; an average 1 mmHg hydrostatic pressure counterbalancing 15 g/l of dextran concentration osmotic force. The calculated hydraulic conductance, Lp, was approximately 0.017 ml/min/mmHg/g and the reflection coefficient, s, for dextran T 40 was 0.1. Both parameters characterize the isolated guinea-pig placenta as leaky.

Animals↗
PubMed1977

Mechanism of action of Zn2+ and Mg2+ on rat placenta alkaline phosphatase. II. Studies on membrane-bound phosphatase in tissue sections and in whole placenta.

Alkaline phosphatase (EC 3.1.3.1) bound to trophoblastic cells in rat placenta is activated by Mg2+ and inhibited by Zn2+ in the same way as is found with partially purified soluble alkaline phosphatase in the same tissue (PetitClerc, C., Delisle, M., Martel, M., Fecteau, C. & Brière, N. (1975) Can. J. Biochem. 53, 1089-1100). In studies done with tissue sections (6-10 micron), it is shown that alkaline phosphatase activity and labelling of active sites by orthophosphate are lost during incubation with ethanolamine at pH 9.0. Addition of Mg2+ causes total recovery of catalytic activity and active sites labelling. Zn2+ displaces and replaces at the Mg2+ binding sites. The affinity for both ions is similar, and dissociation of Zn2+ from the enzyme is a very slow process, even in the presence of Mg2+. The Zn2+-alkaline phosphatase and Mg2+-alkaline phosphatase, which only differ by the ion bound to an apparent modulator site, have the same catalytic activity at pH less than 7.0, but the Zn2+ species has little activity at alkaline pH. Phosphorylation of the enzyme by orthophosphate indicates that with both enzyme species phosphoryl intermediate does not accumulate at alkaline pH. These results suggest that with orthophosphate, the phosphorylation step is rate determining for both enzymes, and that Zn2+ affects this step to a much greater extent. It is proposed that Zn2+ and Mg2+ regulate alkaline phosphatase in rat placenta. The concentration of both ions in maternal serum and placenta suggest that such a mechanism could exist in vivo.

Alkaline Phosphatase↗
PubMed1974

Protein binding by specific receptors on human placenta, murine placenta, and suckling murine intestine in relation to protein transport across these tissues.

Human, rat, and mouse placentas and rat and mouse intestines were homogenized in buffered saline, and fraction consisting primarily of cell membranes was separated from each of the homogenates by differential centrifugation. Human, bovine, and guinea pig IgG, and human IgE, Bence-Jones protein, serum albumin, insulin, and growth hormone were labeled with (131)I or (125)I, and the binding of these proteins by the cell membrane fractions was investigated. Rat and mouse sucklings were given labeled proteins intragastrically, and the amount of each protein absorbed after a given interval of time was determined. It was found that the degree and specificity of protein binding by the cell membrane fractions from human and murine placentas strikingly paralleled the relative rate and specificity of protein transport from mother to fetus in the respective species at or near term. Similarly, the degree and specificity of protein binding by the cell membrane fractions from suckling rat and mouse intestines tended to parallel the rate and specificity of protein absorption from the gastrointestinal tract in these animals. However, some discordance between protein binding and protein transport was also observed. The data suggest that: (a) the binding of a protein by specific receptors on cell membranes may be a necessary first step in the transcellular transport of the protein; (b) specific protein binding by cell receptors does not ensure the transport of that protein across the tissue barrier; and (c) specific transport mechanisms other than or in addition to specific cell membrane receptors are involved in the active transport of proteins across the human or murine placenta or the suckling murine intestine.

Animals↗
PubMed1981

[Studies on immunoreactive ACTH from human term placenta. (I) Detection of a high molecular weight-immunoreactive ACTH in term placenta (author's transl)].

Extracts of human term placenta were fractionated by Sephadex G-75 gel filtration and assayed for immunoreactive ACTH. Both high and low molecular weight protein fractions were detected to be immunologically reactive toward anti-human ACTH (1--39 alpha) antibody. For the extraction of low molecular weight ACTH from human term placenta (pl. -ACTH), a glacial acetic acid-acetone mixture was employed, while a pH 3.0-HCl solution was used for high molecular weight immunoreactive ACTH. The high molecular weight immunoreactive ACTH fraction (F-I), co-eluted with horse hemoglobin from a Sephadex G-75.column in 0.1M acetic acid, was essentially devoid of low molecular weight materials as revealed by polyacrylamide gel disc electrophoresis at pHs 9.5 and 4.3. Tryptic digestion of F-1 at pH 8.1 and 37 degrees C for 4 hr with E/S of 1/100, followed by fractionation with a Sephadex G-75, resulted in the formation of lower molecular weight fragments. One fragment was eluted at the same position as that of porcine ACTH with a recovery of 86% of immunoreactivity of F-I. Another fragment which was eluted last exhibited positive beta-endorphin receptor binding activity. These results suggest the presence of a common precursor protein to ACTH and beta-endorphin in human term placenta.

Adrenocorticotropic Hormone↗
PubMed2004

Identification of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD)-inducible and -suppressive genes in the rat placenta: induction of interferon-regulated genes with possible inhibitory roles for angiogenesis in the placenta.

Exposure to a low dose of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) results in a variety of toxic manifestations, including fetal death. In order to evaluate the effects of low dose TCDD on placental function, pregnant Holtzman rats were given a single oral dose of 1600 ng TCDD/kg body wt or an equivalent volume of vehicle (control) on gestation day 15 (GD15), and changes in the gene expression in the placenta on GD20 were analyzed by two comprehensive methods, representational difference analysis (RDA) and DNA microarray technology. Candidates of TCDD-inducible and -suppressive genes were selected. Quantitative real-time PCR analysis was then performed to verify the induction or suppression levels of the candidate genes. Finally, we identified 81 TCDD-inducible and 21 TCDD-suppressive genes from the placenta of TCDD-treated Holtzman rats on GD20. One of the remarkable profiles of the gene expression was that glucose transporters were strongly up-regulated by the TCDD treatment. Furthermore, many interferon-inducible genes were also up-regulated by the treatment. They included several cytokines such as IP-10 known as a potent angiogenesis inhibitor. In addition, interferon molecules are known to suppress angiogenesis. The above observations suggest that activation of the interferon signaling pathway and the induction of anti-angiogenic factors by TCDD might have a role in causing the inhibition of neovascularization, resulting in the hypoxic state of placenta and increased incidence of fetal death.

Animals↗
PubMed1977

The passage of thiamine across the rat placenta and its uptake by the fetal organs. I. The transport of thiamine across the placenta.

It is well known that thiamine is highly soluble in water. However, if chloroplatinic acid (H2PtCl6) is used during fixation, an insoluble, electron-dense thiamine-PtCl6 precipitate is formed. Using this method we performed electron microscope autoradiography of the placental labyrinth of rats in their 15th day of pregnancy after injection into the maternal bloodstream of 3H-thiamine, and we also measured the radioactivity of the tissues, in order to study the transport of the thiamine across the placenta. Both developed silver grains and radioactivity were found in the largest amounts 30 min after injection; the amounts of both declined after 2 hrs and declined further after 5 hrs. The majority of the developed silver grains were localized in the smooth-surfaced endoplasmic reticulum, which is generally thought to be the vehicle for the transport of materials in the cell, while in the mitochondria, Golgi apparatus, etc. the grains were few. Considering the substantial depletion of the amounts of both sivler grains and radioactivity after the relatively short time of 5 hrs, we conclude that the greater portion of the thiamine passes quickly across the placenta to the fetus, where it is used in the metabolism of the fetal organs, and that only a small part of the thiamine is retained in the placenta for its own metabolism.

Animals↗
PubMed1979

Water and ion metabolism in placenta. II. Water compartments and electrolytes in slices of rabbit placenta, at different periods of gestation, incubated at 0-1 degree C.

The movement and the distribution of water, sodium, potassium, chloride, magnesium and calcium have been studied in slices prepared from rabbit placentae at different periods of gestation, incubated in condition of depressed metabolism (0-1 degree C). In these conditions the tissue takes up water from the external medium up to a maximum of about 2.0 kg/kg d. wt., which represents 30 per cent of the initial H2O content of the fresh tissue. The extracellular compartment swells progressively and proportionally to the age of the placenta. The sodium and chloride content of the tissue increases while that of potassium decreases and their intracellular concentration reaches, after 120 min, that of the external medium. Magnesium does not show appreciable changes and calcium, too, despite its extreme variability, does not seem to undergo significant variations during the cold incubation. The results obtained show that placenta, like most of other mammalian cell systems, possesses specific metabolism-dependent mechanisms responsible for the maintenance of water distribution and ion gradients among the different tissue compartments. The characteristics and the regulation of these mechanisms are discussed in detail.

Animals↗
PubMed2002

[Rich hematopoietic stem/progenitor cells in the human placenta tissue and placenta blood].

Clinical transplantation evidence has indication that umbilical cord blood (UCB) can be useful in the hematopoietic reconstitution in the children, but not well in the adult patients because of the low cell count. The purpose of our study was to evaluate a new method for collection of blood cells from human placenta and umbilical cord. We have simultaneously harvested blood cells from umbilical cord (UCB), placenta blood (UPB) and placenta tissue (UPT) for their content of nucleated cells, CD34 (hematopoietic stem progenitor marker) positive cells. Result showed that the nuclear cell (NC) from UPB and UPT has three to four times than that from umbilical cord blood only, (8.3 +/- 1.04) x 10(8) (UCB), (16.33 +/- 5.54) x 10(8) (UPB), and (8.01 +/- 2.64) x 10(8) (UPT). CD34(+) cells are (0.77 +/- 0.01) x 10(6), (1.25 +/- 0.55) x 10(6) and (4.21 +/- 1.90) x 10(6) respectively. The cells from UPB and UPT have more survival ability than the cells from UCB in the long-term cell culture condition. It is clear that the blood stored in the liquid nitrogen did not show large loss of total nucleated cell count and CD34(+) cells. It was observed that UPT and UPB contained more suppressor lymphocytes, which may be important in prevention of graft-versus-host disease. In conclusion, our data may have implications for the development of placental blood collection together with umbilical cord blood banking for the stem cell transplantation.

Antigens, CD34↗
PubMed1992

Bovine retained placenta: effects of collagenase and hyaluronidase on detachment of placenta.

A significant percentage of cows (11%) fail to release the placenta within 12 h postpartum. Failure of collagen breakdown seems to be related to the retention of placentas. Sections of placentomes incubated with bacterial collagenase caused an increase in placentome proteolysis (6.6-fold) and placentome collagenolysis (94-fold) within 4 h in a dose-related fashion (r = 0.94). Injections of collagenase (825 U/cc) into the placentomes, via umbilical vessels, decreased the cotyledon-caruncle binding force (determined by manometry) to 30 +/- 5 mm Hg from 97 +/- 2 mm Hg, and increased proteolysis by 42% within 8 h (r = -0.95). Hyaluronidase at various concentrations (400-8 250 U/cc) and at various incubation times (up to 8 h) was not effective. Hyaluronidase (825 U/cc) and collagenase (825 U/cc) were not synergistic in loosening cotyledon-caruncle attachment. A single 15-min collagenase pulse, given prior to perfusion with collagenase-free blood, was as effective in loosening cotyledon attachment as was a sustained 2-h perfusion of blood with collagenase added. It was concluded that collagenase caused collagenolysis and loosening of cotyledon from caruncle, but collagenolysis and cotyledon-caruncle separation were not facilitated by the presence of hyaluronidase.

Animals↗
PubMed1992

Glycosphingolipid expression in spontaneously aborted fetuses and placenta from blood group p women. Evidence for placenta being the primary target for anti-Tja-antibodies.

A 12-week-old fetus and one 17-week-old fetus + placenta were obtained after spontaneous abortions from two women of blood group p. The 17-week-old fetus was dissected into intestine, liver, brain and residual tissue. Nonacid glycosphingolipid fractions were prepared from the tissues. Glycolipid characterization was carried out using thin layer chromatography immunostained with monoclonal antibodies and bacteria and by 1H NMR spectroscopy and mass spectrometry. In the placental fraction substantial amounts of globotetraosylceramide (P-antigen) and globotriaosylceramide (Pk-antigen) were identified. In contrast, the fetuses contained only trace amounts of these structures, as revealed by immunostaining. These results indicate that the primary target for the antibodies of the anti-Tja serum is the placenta tissue, resulting in termination of the pregnancy.

Abortion, Spontaneous↗