Reversible calcium inhibition of the membrane-dependent cleavage of pre-placental lactogen in ascites cell-free extracts.
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Calcium↗
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Results for “PLACENTAL EXTRACTS”
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[Effect of the protein-free calf-blood-extract (Solcoseryl) on the excretion of estrogens in chronic placental insufficiency].
In a double blind study the action of Solcoseryl was tested in 31 patients during late pregnancy with chronic placental insufficiency. Under treatment with Solcoseryl a significant increase in urinary estrogen excretion occurred in relation to the placebo-group.
Actihaemyl↗
Human placenta and fetal membranes contain peptide YY1-36 and peptide YY3-36.
Extracts of human term amniotic, placental, and chorion/decidua tissue contained, respectively, 4.36 +/- 2.79 (pmol/g wet wt; mean +/- S.E.M.: n = 5). 2.78 +/- 0.5 (n = 5) and 0.68 +/- 0.68 (n = 5) peptide YY (PYY)-like immunoreactivity. Using a specific PYY antiserum, gel filtration chromatography and reverse-phase high performance liquid chromatography (HLPC), amniotic, placental and fetal intestinal tissue extracts were demonstrated to contain PYY-like immunoreactivity consisting of equal amounts of PYY1-36 and PYY3-36. The presence of pancreatic polypeptide was not detected in any of the extracts. Positive immunohistochemical staining for PYY was seen in extravillous trophoblasts in the decidual septa and fetal membranes, the syncytiotrophoblast and cytotrophoblasts, amniotic epithelial cells and in maternal decidual stromal cells. Positive staining for PYY was found at the earliest date examined (9.5 weeks) and remained present throughout pregnancy to term. PYY1-36 and PYY3-36 may play important roles in human pregnancy, acting via endocrine or paracrine mechanisms.
Amnion↗
Suppression of in vitro lymphocyte reactivity to phytohemagglutinin by placental protein 14.
Crude human decidual extracts containing up to 26.6 mg/l of placental protein 14 (PP14) and purified PP14 were assessed for their effects on the in vitro lymphocyte reactivity to phytohemagglutinin (PHA). Both decidual extract and purified PP14 suppressed the mitogenic response to PHA with the suppression being dose-dependent over the range of PP14 concentrations investigated (0-26.6 mg/l). On the specific reduction of the PP14 content by a monoclonal anti-PP14 immunoadsorbant the suppression was reduced. The suppressive activity of PP14 was related to the degree of proliferation of the stimulated lymphocytes. These results suggest that PP14, which is present at peak levels in the first trimester of pregnancy and constitutes up to 10% of the soluble protein content of decidual tissue, may be an immunomodulator important for the survival of the implanting embryo and maintenance of early pregnancy.
Decidua↗
Detection and partial characterization of two bovine pregnancy-specific proteins.
Two pregnancy-specific proteins were detected by immunoelectrophoresis using antisera developed to homogenates of bovine extraembryonic membranes. Antisera also reacted to extracts of endometrium from pregnant cows and extraembryonic fluids. However, antisera did not react with a preparation presumed to be bovine placental lactogen, fetuin, extracts of various somatic tissues from pregnant cows or extracts of endometrium from nonpregnant cows. One of the proteins had an estimated molecular weight of 65,000-70,000, an isoelectric point of 4.6-4.8 and yielded a reaction of identity with bovine alpha 1-fetoprotein by immunodiffusion. The second protein yielded a reaction of identity with bovine alpha 1-fetoprotein by immunodiffusion. The second protein had no immunological cross-reactivity with the known proteins or organ extracts which were tested. The molecular weight and isoelectric point was 47,000-53,000 and 4.0-4.4, respectively. These data demonstrate the presence of at least 2 pregnancy-specific proteins in cattle.
Animals↗
Demonstration of placental and placental-like alkaline phosphatase in non-malignant human tissue extracts using monoclonal antibodies in an enzyme immunoassay.
The occurrence and nature of heat-stable placental-type alkaline phosphatase (Pl-ALP) in extracts from a variety of non-malignant human tissues has been investigated using monoclonal antibodies in a sensitive solid-phase enzyme immunoassay. The presence of Pl-ALP was confirmed in testicular, cervical and lung tissue extracts, and trace amounts were also detected in extracts from mammary and ovarian tissue. Evidence is presented that normal testis contains at least two forms of Pl-ALP, the major component being an L-leucine-inhibitable placental-like enzyme which is not the D-variant of Pl-ALP. These results have a bearing on the occurrence of Pl-ALP and placental-like ALP activity in malignancy.
Alkaline Phosphatase↗
Thyrotropin-releasing hormone metabolism and extraction by the perfused guinea pig placenta.
This report describes the extraction of synthetic TRH and its metabolic conversion in the perfused guinea pig placenta. These studies were performed to obtain an estimate of fractional fetal TRH losses through the placenta and to determine if some of these losses are due to TRH metabolism. The in situ guinea pig placenta was perfused through an umbilical artery for 90 min, and placental effluent fractions were collected at timed intervals from the umbilical vein. Experiments were performed in which the perfusion buffer contained 0.01, 1, and 10 micrograms/ml or no synthetic TRH. Synthetic TRH was always perfused in the presence of 3H2O. In experiments in which TRH was perfused, the perfusion reservoir contents and placental effluent fractions were counted for 3H, and TRH and deamido-TRH were determined by RIA. Similarly, cyclo(His-Pro) was measured when 10 micrograms/ml TRH were perfused. When no TRH was perfused, the perfusion reservoir and placental effluent contents were processed to determine their content of TRH immunoreactivity. When synthetic TRH was perfused, steady state TRH concentrations were achieved in placental effluent fractions by 20-30 min. The single pass extraction of TRH by the placenta was 11.4 +/- 2.6% (mean +/- SE) compared to 56.9 +/- 7.0% for 3H2O (P less than 0.001). No significant difference was detected regardless of whether 10, 1, or 0.01 micrograms/ml TRH were perfused. A portion of the TRH that perfused the placenta was converted to deamido-TRH at all concentrations of perfused TRH. No conversion of TRH to cyclo(His-Pro) was noted when the highest concentration (10 micrograms/ml) of TRH was perfused. The conversion of TRH to TRH-OH was 4.2 +/- 0.7% in a single pass. When the perfusion buffer was devoid of synthetic TRH, a small but significant increase in the content of TRH immunoreactivity was noted in the placental effluent compared to that in the perfusion reservoir. This was not large enough to affect calculations of the placental extraction of TRH. These studies, in addition to demonstrating that the placenta contains TRH deamidase activity, suggest that losses of fetal TRH through the placenta are not large. They do not support the current impression, based on the fetal TSH response to maternal TSH administration, that the placenta is freely permeable to TRH.
Animals↗
Biochemical characterization of a reverse transcriptase activity associated with retroviral-like particles isolated from human placental villous tissue.
The presence of budding type-C retroviral-like particles in normal placental trophoblast, particularly at the basal surface of the placental syncytiotrophoblast, is well documented. Retroviral-like particles were isolated from human placental villous tissues using isopycnic sucrose gradient centrifugation. Reverse transcriptase activity (RTase) associated with isolated retroviral-like particles was characterised using a combination of synthetic template-primers. These studies showed that RTase activity was more specific with poly(rC).oligo(dG)12-18 than poly(dC).oligo(dG)12-18. Furthermore, activity was detected with poly(rCm).oligo(dG)12-18, a template-primer which has previously been shown to be specific for retroviral RTase. Maximum activity appeared at a sucrose density between 1.15-1.17 g/ml, characteristic of enveloped retroviral particles. Electron microscopy examination of the gradient purified particles revealed morphology and size similar to other retroviruses. Endogenous retroviral particles were isolated from 26 out of 32 (81%) first-trimester placental villous tissue extracts. These particles are likely to be product of endogenous proviral sequences present in the germline of humans. Although these studies showed presence of intact retroviral particles in placental tissues, it was not possible to propagate the isolated particles in vitro. All attempts to propagate placental retroviral particles by co-cultivation with human cells (U937 and JAr choriocarcinoma cells) and long term placental villous tissue explant cultures were unsuccessful. Subsequently, there was no evidence of retroviral-like particles or RTase activity in these cell cultures, including after stimulation with 5'-azacytidine or dexamethasone, chemical agents known to stimulate particle production in virus-infected lines.
Centrifugation, Density Gradient↗
Microheterogeneity of human placental lactogen showing different patterns in individuals.
Samples of human placental lactogen, obtained either as a standard pooled preparation or prepared from individual placentas, were shown to migrate as a single band on acrylamide gel electrophoresis. When subjected to isoelectric focusing in polyacrylamide gels, the pooled sample was resolved into bands at pI values 5.0, 5.5, 5.8. 6.0, 6.1 and 6.2. Different batches of the standard pooled sample gave different proportions of each isoprotein species. Isolation and refocusing of individual bands did not alter the pI of each. Treatment with urea or with p-chloromercuribenzoate did not eliminate microheterogeneity seen on isofucising, indicating that the observed heterogeneity is probably not due to conformational differences or to restriction of molecular shape of disulfide bonds. It was shown by immunodiffusion that all the isofocusing reacted similarly against a common antibody to human placental lactogen. When placental lactogen was extracted from individual full term human placentas, the same isoprotein bands were observed but their proportions varied markedly from one placenta to another, and not all bands were present. Thus human placental lactogen displays considerable microheterogeneity which varies with individual placentas.
Electrophoresis, Polyacrylamide Gel↗
Identification of somatostatin in the human placenta.
High pressure liquid chromatography (HPLC), gel chromatography and radioimmunoassay (RIA) were applied to the identification of cyclic somatostatin in human placental tissue. Methanol extracts of the placenta were treated with acetic acid and chloroform, purified on an octadecylsilane column, fractionated on HPLC and gel filtration, and assessed by RIA. It is concluded that human placental somatostatin is similar or identical to cyclic somatostatin on other tissue.
Chromatography, Gel↗
Persistence of human cytomegalovirus DNA sequences without cell-virus homology in human placental explants in culture.
Using histopathology, virology, and molecular probing, we investigated the potential of human first-trimester placental tissue to support human cytomegalovirus (HCMV) infection. Histopathologic examination of infected placental explants revealed cellular changes characteristic of HCMV infection. Immunohistochemical staining of infected explants with human convalescent sera demonstrated expression of HCMV antigens within the cytotrophoblast. Dot blot hybridization of DNA extracted from infected placental tissue using cloned Hind III "W" fragment of HCMV genome indicated the presence of HCMV sequences without virus-cell homology in infected explants from one to ten days post-infection. In general, the sequences detected by the viral probes increased in abundance with time as infection continued.
Antigens, Viral↗
Structure and expression of cDNA for an inhibitor of blood coagulation isolated from human placenta: a new lipocortin-like protein.
An inhibitor of blood coagulation, a new protein with an apparent molecular weight of 34,000 and an isoelectric point of 4.9, was purified from human placental tissue by EDTA extraction. Five cDNA clones were isolated from the human placental lambda gt11 cDNA library using the mouse monoclonal antibody raised against the coagulation inhibitor as the probe. The longest insert consists of 1,566 nucleotides, and contains 960 nucleotides entirely encoding the 320 amino acids of the inhibitor, and a poly A tail. The deduced amino acid sequence was corroborated by chemical analyses of the protein. The entire amino acid sequence shows homology to those of lipocortin I, lipocortin II, and endonexin-related proteins. The cDNA for the inhibitor was expressed in Escherichia coli under the regulation of the trc promotor of the plasmid pKK233-2. The resulting recombinant protein manifested inhibitory activities against both blood coagulation and phospholipase A2 activity, as did the coagulation inhibitor isolated from human placenta.
Amino Acid Sequence↗
The specific 3H-ouabain binding to Na+/K+-ATPase of the human placental tissue is inhibited by newborn plasma extracts.
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Female↗
Extraction of adrenal cortex hormone activity from placental tissue.
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Adrenal Cortex↗
The application of a monoclonal antibody for the detection of human placental alkaline phosphatase in sera and tumor extracts of cancer patients.
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Alkaline Phosphatase↗
The physiology of growth hormones (GHs) in pregnant women and partial characterization of the placental GH variant.
This work was undertaken to study the heterogeneity of GH in serum and placental and pituitary extracts and to study GH physiology in pregnant women. Two distinct monoclonal antihuman GH (anti-hGH) antibodies (MAb) coded 5B4 and K24 were selected for their high binding affinity and specificity. The 5B4 MAb recognized the epitope comprising the NH2-terminal end of hGH, and the K24 MAb recognized an internal epitope. Both MAbs were used in RIAs to measure serum GH concentrations in various circumstances, including pregnancy. The two RIAs yielded slightly different serum GH results in normal men and nonpregnant women, but the overall correlation between the data was excellent. Since the RIAs were not affected by human placental lactogen, the evolution of serum GH in pregnant women could be studied. In such women, serum GH levels progressively declined to undetectable levels during the second half of pregnancy, while a pregnancy-associated serum GH-like antigen [tentatively called human placental growth hormone (PGH)] appeared in the circulation at midpregnancy and increased thereafter up to term. PGH contained the NH2-terminal epitope of pituitary GH, but lacked the internal one. Consequently, it reacted selectively with the 5B4 MAb only. After delivery, PGH disappeared from maternal serum within 1 h. Amniotic fluid contained low GH concentrations; cord serum contained high GH levels, but no PGH. Thus, PGH appears to be secreted selectively into the maternal compartment. PGH was purified from term placenta extracts. According to its chromatographic behavior, it appears more basic than pituitary 22K and 20K GHs. Size dimorphism was demonstrated; PGH was composed of two entities of 22K and 25K, respectively. Pure PGH, obtained in small quantities by preparative electrophoresis, was found to bind to hepatic GH receptor with an apparent high potency compared to that of pituitary GH, PGH, thus, should act in vivo as a GH agonist sharing most of its biological properties. These results lead to the conclusion that PGH is likely to replace the pituitary hormone in governing maternal metabolism during the second half of pregnancy.
Amniotic Fluid↗
The effect of maternal asthma on placental and cord blood protein profiles.
OBJECTIVE: We conducted a comparative proteomic analysis of placental and umbilical cord blood proteins using surface-enhanced laser desorption ionization-time of flight mass spectrometry (SELDI-TOF MS) to examine the associations among asthma, fetal gender, and protein profiles. METHODS: Placental tissue and umbilical vein plasma were collected from 10 healthy and 20 asthmatic women. Placental proteins were extracted using phosphate-buffered saline containing protease inhibitors. Samples were applied to the surfaces of strong anion exchange (SAX2), weak cation exchange (WCX2) and immobilized metal affinity capture (IMAC-Cu(2+)) chips. Mass analysis was conducted using a Ciphergen Protein Biology System IIc (Freemont, CA), and differences in individual peak intensities between groups were determined. RESULTS: Fourteen placental peaks were significantly different between asthmatic and non-asthmatic women (seven more highly expressed and seven less highly expressed). Ten umbilical cord blood peak differences were identified, with four peaks more highly expressed and six peaks less highly expressed in asthmatics. Four placental and three umbilical cord blood proteins differed significantly between male and female fetuses. Two placental and five umbilical cord blood peaks were specifically increased in a subgroup of samples collected from asthmatic women who did not use inhaled glucocorticoids and were pregnant with a female fetus, a group previously found to have altered placental function. CONCLUSIONS: This study demonstrates the abilities of the SELDI technique as a tool for protein profiling in tissue or plasma. Further work to positively identify the candidate peptides found in this study may provide a greater understanding of the placental mechanisms leading to alterations in fetal growth in patients with bronchial asthma.
Adult↗
Identification of 19-hydroxy-progesterone in human placenta.
We have tentatively demonstrated the presence of a 19-hydroxylated C21 steroid, 19-hydroxy-progesterone, in normal human placenta. A 19-hydroxylated steroid such as 19-hydroxy-progesterone, if produced by the placenta, could serve as a precursor for such hypertensinogenic 19-nor-steroids as 19-nor-deoxycorticosterone and 19-nor-progesterone. Freshly delivered, homogenized placental tissue was extracted and subjected to thin layer chromatography. A steroid corresponding to standard 19-hydroxy-progesterone was subsequently purified in HPLC, where authentic 19-hydroxy-progesterone and the sample had the same retention time. The identity of the sample was further confirmed by repeat HPLC after acetylation and mass spectrometry. Our experiment indicates that 19-hydroxy-progesterone is present in term placental tissue, where it appears to be synthesized.
Acetylation↗