Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PLACENTAL HORMONES”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 559 records · Page 31Linked to original sources
PubMed1971

The plasma estradiol as an index of fetoplacental function.

A radioligand assay has been developed for the measurement of unconjugated 17beta-estradiol in as little as 0.01 ml of pregnancy plasma employing rabbit uterine cytosol as specific binder and activated charcoal as nonspecific absorbant. Large numbers of samples could be processed simultaneously at relatively little expense and results were obtainable within 3 hr. The procedure was sensitive to 1 ng/ml. No diurnal or positional variations were found. Values from 250 unselected normal patients showed a constantly rising mean plasma E(2) from 18 to 35 wk gestation from 4.5 to 14 ng/ml. From 35 to 40 wk, mean E(2) rose only to 15 ng/ml and the range of values increased substantially. When 22 normal pregnant subjects were followed serially, rising levels of plasma E(2) were found with no significant fall ever seen. By contrast, patients exhibiting fetal distress generally had falling or reduced E(2) levels. However, 3 cases of Rh isoimmunization had elevated or normal E(2) concentrations even after clearcut evidence of fetal demise. A decrease of 45% in E(2) concentration was associated with intraamniotic instillation of hypertonic saline prior to delivery supporting the view that placental conversion of maternal adrenal precursors is responsible for about half of the E(2) production in pregnancy. The postpartum clearance of endogenous E(2) was measured and found to fit a two compartment model with mean half-time of 22 min and 7 hr. Follicular phase levels of E(2) were attained by 35 hr postpartum. The concentration of unconjugated E(2) in pregnancy plasma correlated as well with the state of the placenta as other placental hormone measurements and holds promise of being a rapid, inexpensive, and reliable method of following patients with high-risk pregnancies in a variety of clinical settings.

Abortion, Induced↗
PubMed2004

Luteal 3beta-hydroxysteroid dehydrogenase and 20alpha-hydroxysteroid dehydrogenase activities in the rat corpus luteum of pseudopregnancy: effect of the deciduoma reaction.

BACKGROUND: In the rat, the maintenance of gestation is dependent on progesterone production from the corpora lutea (CL), which are under the control of pituitary, decidual and placental hormones. The luteal metabolism of progesterone during gestation has been amply studied. However, the regulation of progesterone synthesis and degradation during pseudopregnancy (PSP), in which the CL are mainly under the control of pituitary prolactin (PRL), is not well known. The objectives of this investigation were: i) to study the luteal metabolism of progesterone during PSP by measuring the activities of the enzymes 3beta-hydroxysteroid dehydrogenase (3betaHSD), involved in progesterone biosynthesis, and that of 20alpha-hydroxysteroid dehydrogenase (20alphaHSD), involved in progesterone catabolism; and ii) to determine the role of decidualization on progesterone metabolism in PSP. METHODS: PSP was induced mechanically at 10:00 h on the estrus of 4-day cycling Wistar rats, and the stimulus for decidualization was provided by scratching the uterus on day 4 of PSP. 3betaHSD and 20alphaHSD activities were measured in the CL isolated from ovaries of PSP rats using a spectrophotometric method. Serum concentrations of progesterone, PRL, androstenedione, and estradiol were measured by radioimmunoassay (RIA). RESULTS: The PSP stage induced mechanically in cycling rats lasted 11.3 +/- 0.09 days (n = 14). Serum progesterone concentration was high until day 10 of PSP, and declined thereafter. Serum PRL concentration was high on the first days of PSP but decreased significantly from days 6 to 9, having minimal values on days 10 and 11. Luteal 3betaHSD activities were elevated until day 6 of PSP, after which they progressively declined, reaching minimal values at the end of PSP. Luteal 20alphaHSD activities were very low until day 9, but abruptly increased at the end of PSP. When the deciduoma was induced by scratching the uterus of pseudopregnant animals on day 4 (PSP+D), PSP was extended to 18 +/- 2.2 days (n = 8). In PSP + D rats, serum progesterone and PRL levels, and luteal 3betaHSD activities were higher than in pseudopregnant rats on day 11. Decidualization also prevented the increase in luteal 20alphaHSD activities observed on day 11 of PSP. Administration of the dopaminergic agonist CB154 in PSP + D rats on day 10 of PSP induced a decline in both serum PRL and progesterone on day 11 of PSP, values that were not different from that of pseudopregnant controls. CONCLUSIONS: We have established that during the final period of PSP a decline in progesterone biosynthesis occurs before the increase in progesterone catabolism. We have also shown that decidualization in pseudopregnant rats extends the life of the CL by prolonging the production of pituitary PRL, and by maintaining high 3betaHSD and low 20alphaHSD activities within the CL leading to sustained production of progesterone.

17-Hydroxysteroid Dehydrogenases↗
PubMed2006

Leptin enhances lung maturity in the fetal rat.

Pulmonary alveolar type II cells synthesize and secrete phospholipids and surfactant proteins. In most mammalian species, the synthesis of phospholipids and proteins of lung surfactant increases with fetal lung maturation, which occurs late in gestation. Factors that may promote lung maturation and surfactant production include the placental hormone, leptin, whose expression increases with advancing gestational age. We demonstrate that physiologic concentrations of leptin (1 and 10 ng/mL) increase the levels of surfactant proteins (SP) A, B, and C mRNA as well as SP-A and SP-B protein in d-17 fetal rat lung explants in vitro. To determine whether leptin exerts similar effects in vivo, we administered leptin antenatally to pregnant rats and compared its effects to that of dexamethasone, a known mediator of fetal lung development. Antenatal treatment with leptin for 2 d significantly increased the average weight of the fetal lungs in relation to their body weight. Histologic analysis revealed that the increase in fetal lung weight was accompanied by an increase in the number and maturation of type II alveolar cells and the expression of surfactant proteins B and C in these cells. Collectively, these results suggest that leptin is a cytokine regulator of rat fetal lung maturity.

Animals↗
PubMed2004

Enhanced recovery from thrombocytopenia and neutropenia in mice constitutively expressing a placental hematopoietic cytokine.

Expression of the placental hormone, prolactin-like protein E (PLP-E), a potent cytokine that acts on multiple myeloid lineages, is normally restricted to pregnancy and certain hematopoietic disease states. We hypothesized that the restricted pattern of PLP-E expression is necessary to avoid hyperstimulation of myelopoiesis. To test this idea, we have produced PLP-E transgenic mice and analyzed their steady-state blood cell levels. We find that blood cell levels remain in the normal range, and thus the constitutive expression of a cytokine of pregnancy fails to overcome the tight control of hematopoietic set points for blood cell levels. In contrast, an effect of constitutive PLP-E expression is detected during the recovery from low blood platelet levels (acute thrombocytopenia) and from low granulocyte levels (acute neutropenia) but not from anemia. Mice producing high circulating concentrations of PLP-E recover more rapidly from both thrombocytopenia and neutropenia, as seen both by an earlier increase of progenitor numbers in the bone marrow and the earlier return to normal circulating blood cell levels.

Anemia↗
PubMed2005

Cathepsins in the ovine uterus: regulation by pregnancy, progesterone, and interferon tau.

Cathepsins (CTS) are peptidases that have biological roles in degrading extracellular matrix, catabolism of intracellular proteins, and processing of prohormones. Expression of CTSB, CTSD, CTSH, CTSK, CTSL, CTSS, and CTSZ genes was detected in the endometria of cyclic and early pregnant ewes with distinct temporal and spatial expression patterns. In the d 18 and 20 conceptus, expression of CTSB, CTSD, CTSL, and CTSZ mRNA was detected in the trophectoderm. Of particular note, CTSL mRNA was the most abundant CTS mRNA in the ovine endometrium and detected only in the luminal epithelium and superficial glandular epithelium of cyclic and pregnant ewes. CTSL mRNA increased 8-fold between d 10 and 18 in endometria of pregnant ewes, whereas it declined between d 14 and 16 in cyclic ewes. CTSL protein was also detected in conceptus trophectoderm, and pro-CTSL was detected in uterine flushings from ewes between d 12 and 16 of pregnancy. In ovariectomized and catheterized ewes, CTSL mRNA in the endometrium was increased by progesterone and intrauterine injections of ovine interferon (IFN)tau. Other endometrial CTS genes were also regulated by progesterone alone (CTSB, CTSK, CTSS, and CTSZ) or progesterone and IFNtau (CTSH, CTSK, CTSS, and CTSZ). These results indicate that CTS of endometrial and conceptus origin may regulate endometrial remodeling and conceptus implantation, endometrial CTS genes are regulated by ovarian and placental hormones, and CTSL is a novel IFNtau-stimulated gene expressed only in luminal epithelium and superficial glandular epithelium of the endometrium.

Animals↗
PubMed1992

Expression and secretion of galanin during pregnancy in the rat.

The expression of galanin messenger RNA (mRNA) in the pituitary and conceptus of pregnant rats has been studied at various stages of gestation. Using Northern blot analysis and in situ hybridization we have found that high levels of mRNA coding for galanin were detected in the conceptus during early pregnancy. The level of expression in conceptuses increased until day 11-12 after which the levels decreased rapidly. In contrast, in the pituitary galanin mRNA continued to increase throughout pregnancy, especially in the latter half of pregnancy as serum estradiol levels has been reported to be increased. The size of the galanin transcript was the same in the conceptus and pituitary (0.9 kilobase). Expression of this mRNA was confined to the decidua and was first seen at day 5 of pregnancy at a time when implantation swellings were first observed. Galanin antisense probe hybridized strongly to the decidual cells that surround the implantation site. At day 11 of pregnancy the galanin mRNA was found in both the antimesometrial and the mesometrial tissue with the highest concentration in the region lateral to the antimesometrial cells and continued toward the mesometrial cells. Serum galanin levels measured by an RIA using synthetic rat galanin as standard and antisera raised against porcine galanin, exhibited a temporal pattern similar to the pattern of mRNA expression in decidua, with a 7.1-fold increase at day 12 of pregnancy followed by a decline. In summary, decidual cells may differentiate into an endocrine cell during pregnancy. The galanin secreted by these cells, in addition to acting locally in a paracrine/autocrine fashion, may function as a placental hormone with systemic effects on distal target tissues.

Animals↗
PubMed2002

Ca2+-activated, large conductance K+ channel in the ovary: identification, characterization, and functional involvement in steroidogenesis.

Progesterone production by the corpus luteum is a process vital for reproduction. In humans its secretion is stimulated by the placental hormone human chorionic gonadotropin (hCG), and this stimulatory action can also be observed in cultured human luteinized granulosa cells (GCs). We now provide evidence that opening of a Ca(2+)-activated K(+) channel, the BK(Ca), is crucially involved in this process. Immunohistochemistry and RT-PCR revealed the presence of the pore-forming alpha-subunit in human luteinized GCs and in luteal cells of human, macaque, and rat, implying that BK(Ca) channels are important throughout species. Blocking of BK(Ca) channels by iberiotoxin attenuated hCG-induced progesterone secretion. The inhibitory action of iberiotoxin suggests that BK(Ca) channels are activated in the course of hCG-induced steroidogenesis. In search of physiological activators we used an electrophysiological approach and could preclude a direct regulation of channel activity by hCG or GC-derived steroids (progesterone and 17beta-estradiol). Instead, the peptide hormone oxytocin and an acetylcholine (ACh) agonist, carbachol, evoked transient BK(Ca) currents and membrane hyperpolarization. These two molecules are both secreted by GCs and act via raised intracellular Ca(2+) levels. The release of oxytocin is stimulated by hCG, and a similar mechanism is likely in the case of ACh. We conclude that BK(Ca) channel activity in GCs is mediated by components of the intraovarian signaling system, thereby interlinking a systemic hormonal and a local neuroendocrine system in control of steroidogenesis.

Animals↗