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 1,009 records · Page 56Linked to original sources
PubMed1990

Identification of a follicle-stimulating hormone receptor-binding region in hFSH-beta-(81-95) using synthetic peptides.

Pituitary and placental glycoprotein hormones are heterodimers with alpha-subunits of identical primary structure, but dissimilar beta-subunits. Regions of structural similarity between the beta-subunits might be involved in interaction with the homologous alpha-subunits, and regions of structural dissimilarity could, therefore, be candidates for receptor interactions. A restrained matrix dot-plot analysis identified hFSH-beta-(8-32) and hFSH-beta-(55-65) as candidates for interaction with alpha-subunit. Therefore, by subtraction, hFSH-beta-(33-54) and hFSH-beta-(66-111) seemed candidates for regions of interaction with receptor. In a previous report we demonstrated that hFSH-beta-(33-53) represented a receptor-binding region of hFSH-beta. Analysis of structural parameters (flexibility, surface probability, secondary structure prediction, etc.) indicates similarities between hFSH-beta-(33-53) and hFSH-beta-(85-95), suggesting the latter might be the component of hFSH-beta-(61-111) interacting with the receptor. Testing of 11 synthetic peptides, corresponding to the primary structure of hFSH-beta, demonstrated that hFSH-beta-(31-45)-peptide amide, were unique in ability to inhibit 125I-follicle-stimulating hormone binding to receptor. hFSH-beta-(81-95)-peptide amide also stimulated estradiol biosynthesis in Sertoli cell cultures. The correlation between binding inhibition and surface probability, flexibility, and predicted secondary structure (alpha, extended, and turn) was highly significant (R2 = 0.87, p less than 0.0001). Regression significance for these parameters, taken individually, were very poor. Receptor-binding regions, therefore, appear to be characterized by a particular and complex arrangement of secondary structure motifs, surface probability, and flexibility.

Amino Acid Sequence↗
PubMed1989

Inhibin and activin modulate the release of gonadotropin-releasing hormone, human chorionic gonadotropin, and progesterone from cultured human placental cells.

Although it is clear that human chorionic gonadotropin (hCG) and progesterone play fundamental roles in pregnancy, the regulation of placental production of these hormones remains to be defined. Recent evidence suggests that the human placenta expresses proteins related to inhibin (alpha beta subunits) or activin (beta beta subunits). Inhibin and activin (follicle-stimulating hormone-releasing protein) possess opposing activities in several biological systems including pituitary follicle-stimulating hormone (follitropin) secretion, erythroid differentiation, and gonadal sex-steroid production. The actions of purified inhibin and activin on hormonogenesis by primary cultures of human placental cells were studied. The addition of activin increased gonadotropin-releasing hormone (GnRH) and progesterone production and potentiated the GnRH-induced release of hCG. Inhibin by itself did not modify placental immunoreactive GnRH, hCG, and progesterone secretion but reversed the activin-induced changes. Neither inhibin nor activin influenced the release of human placental lactogen. Furthermore, transforming growth factor beta, structurally related to inhibin/activin, did not significantly influence hormone release from cultured placental cells. These results support the hypothesis that inhibin and activin may play a role in regulating the release of GnRH, hCG, and progesterone from placenta and implicate inhibin-related proteins in the endocrine physiology of human pregnancy.

Activins↗
PubMed1979

Role of phospholipids in the structure and function of the thyrotropin receptor.

Phosphatidylinositol, phosphatidylserine, and phosphatidylethanolamine interact with 125I-thyrotropin and inhibit its binding to thyroid plasma membranes; phosphatidylcholine is not similarly effective. The interaction has been monitored by column chromatography on Sephadex G-100 which shows, for example, that 125I-labeled thyrotropin forms an adduct with phosphatidylinositol but not with phosphatidylcholine. Formation of the 125I-labeled thyrotropin-phosphatidylinositol adduct is dependent on the phosphatidylinositol concentration but can be reversed by both unlabeled thyrotropin and excess membranes. The efficacy of the phospholipid interaction and the phospholipid inhibition of thyrotropin binding to thyroid membranes is paralleled by changes in fluorescence and fluorescence polarization imposed on the 5-dimethylamino-1-naphthalene sulfonate (dansyl) derivative of thyrotropin. These changes are reversed by unlabeled thyrotropin but not by prolactin, placental lactogen, or growth hormone; similar changes are not observed when phospholipids are incubated with dansylated growth hormone, prolactin, and placental lactogen. Monovalent potassium, sodium, and lithium salts neither prevent nor reverse the formation of the phospholipid-dansyl-thyrotropin adduct; these results contrast with the effects of the same salts on the formation of ganglioside adducts with dansyl-thyrotropin. Despite their ability to interact witw 125I-thyrotropin in solution, neither phosphatidylinositol, phosphatidylserine, nor phosphatidylethanolamine, when incorporated in a liposome, binds the 125I-labeled ligand. These same phospholipids have no effect on ganglioside binding of 125I-labeled thyrotropin when gangliosides are incorporated in a liposome. These phospholipids do, however, modulate the expression of the glycoprotein component of the thyrotropin receptor when it is imbedded in a liposome. The phosphatidylinositol in this case serves as a negative modulator, both by decreasing the incorporation of the glycoprotein component of the receptor into the liposome and by inhibiting the binding activity of the glycoprotein component which is incorporated. Speculation is offered as to a possible role of the phospholipids in the message transmission process which would be consistent with current studies demonstrating a direct interaction of acidic phospholipids with thyrotropin. The effect of phospholipids on liposomes containing the glycoprotein component of the thyrotropin receptor raises the possibility that phospholipids and, in particular, phosphatidylinositol, may also play a role in regulating the insertion and expression of this receptor component in thyroid plasma membranes.

Animals↗
PubMed1984

Endocrinological problems in malformation of the male genitalia.

There are two groups of congenital defects of the male genitalia: defects of organogenesis (e. g., aplasia of the external genitalia) and malformations due to defective hormonal influences on these organs. The pathophysiological mechanisms of the functional malformations can be a defect of androgen biosynthesis in the gonads, defects of conversion of precursor hormones into the biologically active compound, and defects at the receptor site with a faulty hormonal utilisation. All these defects in the production of a biologically active substance can be present and operating very early in life, i. e., in the embryonal or foetal period. Problems can arise from the mother and particularly the placenta, or from the child (pituitary). The production of an antimüllerian hormone in Sertoli cells has been recently reported as an additional important mechanism. These hormonal defects influence the development of the male genitourinary tract system. Testosterone biosynthesis has several enzymatic steps: The synthesis of androgens starts early in the embryonal period, with the final transformation of the indifferent organ into the differentiated external male genitalia occurring under the influence of the foetal testosterone. Targets for these hormonal malfunctions are, besides the urogenital system, an enzyme (5-alpha-hydroxylase) and cytoplasmic and nuclear receptor sites on the skin of the external genital region. One of the clinical manifestations of such a hormonal malfunction is a defective virilisation of the external male genitals, with several types of hypospadias. Complete and partial defects of testosterone biosynthesis are known. Extensive laboratory investigations disclose the specific defect. Besides hypospadias, similar malformations occur in the form of ambiguous external genitalia if testosterone cannot metabolize into dihydrotestosterone in the target cell. In earlier descriptions this congenital genitourinary defect was called pseudovaginal perineoscrotal hypospadias. Today, the specific defect is identified as a 5-alpha-reductase deficiency. The diagnosis is established by a skin biopsy of the genital area. Ambiguous genitalia of variable expression are present if the receptor sites at the target cells are defective. The clinical presentation is known as testicular feminization or hereditary male pseudohermaphroditism. Incomplete partial expression of this disorder is known. The diagnosis is made clinically, and diagnosis is proven by investigation of hormone receptor sites in the target cells in the skin of the genital region.(ABSTRACT TRUNCATED AT 400 WORDS)

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1995

Specific endometrial binding sites for bovine placental lactogen are antigenically similar to the growth hormone receptor.

Bovine liver growth hormone receptors bind both bovine growth hormone (bGH) and bovine placental lactogen (bPL) with high affinity (Kd = 1.4 x 10(-11) M and 3.0 x 10(-11) M, respectively). By contrast, the uterine endometrium of pregnant cattle has high-affinity (Kd = 8.0 x 10(-11) M) binding sites for bPL but, displays negligible binding of bGH. A polyclonal antiserum raised against the extracellular domain of the bGH receptor, was used to determine if there was antigenic similarity between the liver bGH receptor and the endometrial bPL binding site(s). On Western blots, this antiserum displayed cross-reactivity with a 180,000-mol wt protein (nonreducing conditions) in detergent-solubilized extracts of microsomal membranes from both tissues. However, different detergents (Triton X-100 for endometrium and 3-[(3-cholamidopropyl)dimethylammonio]-1-propane-sulfonate [CHAPS] for liver) were required to solubilize the cross-reacting protein in the two tissues. The purified immunoglobulin fraction from this same antiserum also blocked binding of [125I]bPL to microsomal membrane preparations from both liver and endometrium. These results indicate that the endometrial binding site for bPL is antigenically similar to the bGH receptor and raise the possibility that it may be a modified GH receptor.

Animals↗
PubMed1983

Pregnancy hormone concentrations in marijuana users.

The maternal serum concentrations of human chorionic gonadotropin, pregnancy-specific beta-l-glycoprotein, placental lactogen, progesterone, 17-hydroxyprogesterone, estradiol and estriol were measured in 13 women who smoked marijuana regularly throughout pregnancy. Cannabinoid use in these women was confirmed by RIA measurements of their serum delta 9-tetrahydrocannabinol (THC) concentrations. These THC using women were matched within 2 1/2 weeks of gestational age with 13 pregnant non-THC using controls drawn from the same population. Placental protein and steroid hormone concentrations were within established normal ranges for gestational age and there were no significant differences between the groups in the concentrations of any of the protein and steroids measured. In addition, no significant differences between THC users were found following linear regression analysis of placental hormone concentrations as a function of gestational age. Thus, this study suggests that marijuana use during pregnancy does not significantly alter the circulating maternal concentrations of trophoblastic protein hormones or major fetoplacental steroid hormones.

Cannabis↗
PubMed1991

Dose-related action of gonadotropin-releasing hormone on basal prostanoid production from the human term placenta.

The dose-related effect of gonadotropin-releasing hormone on placental prostanoids was studied with a perifusion system. Villous tissues were perifused with medium 199 (1 ml/hr) and at the beginning of the fifth hour, either 0, 10(-10), 10(-9), 10(-8), 10(-7), or 10(-6) mol/L gonadotropin-releasing hormone was added to the medium of triplicate chambers. The concentration of prostaglandin E, prostaglandin F, 13,14-dihydro-15-keto-prostaglandin F2 alpha, 6-keto-prostaglandin F1 alpha, and thromboxane B2 in the effluent medium, collected every hour, was determined by specific radioimmunoassay. The cumulative release after gonadotropin-releasing hormone treatment for each chamber was calculated, and replicate chambers were averaged. Linear regression analysis of the average for each dose from three different placentas was used to determine the dose-response relationship. Gonadotropin-releasing hormone significantly inhibited the release of placental prostaglandin E, prostaglandin F, and thromboxane B2 in a dose-dependent fashion. Gonadotropin-releasing hormone had no significant effect on 13,14-dihydro-15-keto-prostaglandin F2 alpha and 6-keto-prostaglandin F1 alpha, although there was an apparent increase in 13,14-dihydro-15-keto-prostaglandin F2 alpha. These data support the hypothesis that chorionic gonadotropin-releasing hormone inhibits prostanoid production from the placenta, which in turn may regulate various functions of prostanoids during pregnancy.

6-Ketoprostaglandin F1 alpha↗
PubMed1977

Immunofluorescent localization of ovine placental lactogen.

The localization of ovine placental lactogen (OPL) was studied using the immunofluorescence method. The placentome sections were treated by an indirect technique with anti-OPL antibodies obtained from rabbits injected with purified hormone. OPL was located in large cells of the monostratified epithelium of chorionic villi. These cells are mono- or binucleated and PAS-positive. The immunological reaction was inhibited by the specific antigen (OPL, 400 microgram/ml undiluted anti-OPL antiserum) but not by ovine prolactin, bovine growth hormone, human placental lactogen nor by any other polypeptidic hormone tested. Reciprocally, the localization of OPL-secreting cells was unsuccessful with antibodies raised against these control hormones.

Animals↗
PubMed2001

Epidermal growth factor regulation of equine glycoprotein hormone alpha subunit expression in trophoblast cells.

Primates and equids are the only species known to express the placental glycoprotein hormone, chorionic gonadotropin (CG), a heterodimeric glycoprotein composed of an alpha subunit linked to a hormone-specific beta subunit. The regulatory mechanisms involved in the induction of equine glycoprotein alpha subunit gene expression have not been identified. Epidermal growth factor (EGF) receptor is known to transduce signals that alter a number of different cellular functions (cell proliferation, differentiation, hormone secretion, and gene regulation). In the present study, we investigated the regulation of the equine alpha subunit gene by EGF in trophoblasts. We found that 2800 base pairs of 5' flanking sequence from the equine alpha subunit promoter is sufficient for basal expression in human choriocarcinoma cells. Epidermal growth factor and phorbol 12-myristate 13-acetate (PMA), an activator of protein kinase C (PKC), increased transcriptional activity of the equine alpha subunit promoter (-2800/+21). These responses were blocked by pretreatment with bisindolylmaleimide-I, an inhibitor of PKC, suggesting an involvement of this pathway downstream of EGF. In addition, PD98059, an inhibitor of the extracellular signal-regulated kinase (ERK) pathway, completely blocked activation of the equine alpha promoter by PMA, suggesting that mitogen-activated protein kinase (MAPK) cascade was involved downstream of the PKC pathway. In conclusion, the EGF/PKC/MAPK pathway regulates equine glycoprotein alpha subunit gene expression through a distinct regulatory region (-2300 to -1900) in trophoblasts, while essential elements for basal expression appear to exist within the -2800 to -1900 region of the promoter.

Animals↗
PubMed1988

[Method and evaluation of hormone assays in practical obstetrics and gynecology].

Hormone assays are very important in obstetrics and gynecology. Today, I want to talk about how to measure hormones and how to evaluate the data obtained for therapeutic purposes. In humans, there are two mechanisms of control, neural control and endocrine control. Generally speaking, the neural system controls organs directly via various neurotransmitters, while the endocrine system controls organs by hormones transported in the blood. In fact, recent progress in hormone research has shown that this concept should be modified, because some hormones act as neurotransmitters or regulate other cells or even endocrine cells themselves in the same organ. But I shall not go into this. Today's lecture is focused on hormones that are closely related to clinical obstetrics and gynecology. The hormones that are important are those in females, reproduction, and pregnancy, and tumors. First, and most important, is that patients acquire femininity in the physiological and psychological sense by hormones. The hormones closely related to this are estrogens and pituitary hormones. For reproduction, cyclic hormonal change is important. In the reproductive period, women have menstruation and ovulation along with cyclic changes of ovarian and pituitary hormones. After conception, various kinds of hormones, including hCG, HPL and estriol, are secreted from the feto-placental system. These hormones are used clinically as a markers of placental function. Hormones also have important roles in oncology. hCG is an excellent marker of trophoblastic diseases. Endometrial cancer is expected respond to large doses of progestins if they have progesterone receptors. There are three types of hormone assays, biological assays, immunological assays and chemical assays.(ABSTRACT TRUNCATED AT 250 WORDS)

Age Factors↗
PubMedDate not supplied

Immunologic and neuroendocrine interactions in pregnancy.

The neuroendocrine system helps in the success of the fetal graft by suppressing maternal cellular immune response against the foreign paternal histocompatibility (HLA) antigens. In addition, placenta absorbs the antibodies directed against the paternal HLA antigens, thus inhibiting the humoral rejection of the fetal graft. In contrast, neuropeptides released in the maternal blood stream under adverse mental states may stimulate lymphocyte blastogenesis and natural killer (NK) cell activity resulting in premature loss of the fetus. Further, homozygosity of a lethal gene which is in linkage disequilibrium with HLA genes may have a role in some unexplained fetal deaths.

Female↗
PubMed1995

Man and the chimaera. Selective versus neutral oxytocin evolution.

The oxytocin/vasopressin superfamily encompasses vertebrate and invertebrate peptides and therefore the ancestral gene encoding the precursor protein antedates the divergence between the two groups, about 700 million years ago. The preserved nonapeptide pattern indicates that both the precursor structures and the processing enzymatic machinery were greatly conserved to ensure the building of a specific conformation. Substitutions, which may be neutral or selective, occurred in precise positions. Virtually all vertebrate species possess an oxytocin-like and a vasopressin-like peptide so that two evolutionary lineages can be traced. Because a single peptide, vasotocin ([Ile3]-vasopressin or [Arg8]-oxytocin) has been found in the most primitive Cyclostomata, a primordial gene duplication and subsequent mutations are assumed to have given rise to the two lineages. They started with vasotocin and isotocin ([Ser4,Ile8]-oxytocin) in bony fishes and culminated with vasopressin and oxytocin in placental mammals. Mesotocin ([Ile3]-oxytocin), found in lungfishes, amphibians, reptiles, birds and marsupials, appears as an evolutionary intermediate. The change from isotocin ([Ser4,Ile8]-oxytocin) into mesotocin ([Ile8]-oxytocin), can be observed in African and Australian lungfishes, species making the transition from bony fishes to land vertebrates. On the other hand the replacement of mesotocin by oxytocin can be detected in marsupials, particularly in the North-American opossum and the Australian Northern bandicoot that have both mesotocin and oxytocin whereas placental mammals possess only oxytocin. The invariability of this peptide in placentals can be explained by receptor-fitting selective pressure. In contrast to bony vertebrates in which neurohypophysial hormones revealed a remarkable structural stability, cartilaginous fishes displayed an unique oxytocin-like hormone evolution with variability and duality. Aside from vasotocin, in the subclass Selachii, rays have glumitocin ([Gln8-oxytocin]) and sharks possess two peptides: aspargtocin ([Asn4-oxytocin]) and valitocin ([Val8-oxytocin]) for the spiny dogfish, asvatocin ([Asn4,Val8]-oxytocin) and phasvatocin ([Phe3,Asn4,Val8]-oxytocin) for the spotted dogfish. In the other subclass Holocephali, the chimaera (ratfish) has oxytocin, the typical hormone of placental mammals. Cartilaginous fishes used urea rather than salts for their osmoregulation and oxytocin-like hormones could have been relieved from osmoregulatory functions and able to accept many neutral variations.

Amino Acid Sequence↗