Biomedical subjects

I T Cameron

Publications and source records attributed to I T Cameron.

At least 19 recordsLinked to original sources

PubMed2006

L-serine uptake by human placental microvillous membrane vesicles.

The human fetus requires more glycine than any other amino acid but placental glycine transfer to the fetus is insufficient to meet fetal demand. L-Serine could represent a major metabolic source of glycine for the human fetus but little is known about the kinetics and physiology of L-serine uptake by the human placenta. We have characterised the amino acid transport systems involved in the uptake of L-serine by the microvillous membrane of the human placental syncytiotrophoblast and compared the uptake rates to those of glycine. L-Serine uptake into microvillous membrane (MVM) vesicles was primarily mediated by system A (MeAIB inhibitable) and system L (BCH inhibitable). Further characterisation using specific substrates of LAT1 and LAT2 found the pattern of L-serine uptake was consistent with that expected for uptake mediated by LAT2. Uptakes were performed with tracer levels of (14)C-L-serine, physiological levels of L-serine, or with physiological levels of amino acids. As amino acid concentrations rose, the proportion of uptake by System L decreased while uptake by uncharacterised Na(+)-independent systems increased. Uptake of Lserine into MVM vesicles had a V(max) of 2.1+/-0.4 nmol/mg protein/min, which was significantly higher than for glycine (V(max) 1.0+/-0.2 nmol/mg protein/min). This indicates that MVM vesicles have a higher uptake capacity for L-serine than glycine, despite a greater demand for glycine over serine for fetal protein synthesis. Further studies are now required to define the fate of L-serine taken up by the placenta and its importance for the fetus.

Amino Acid Transport System A↗

PubMed2004

Progesterone inhibits insulin-like growth factor binding protein-1 (IGFBP-1) production by explants of the Fallopian tube.

The Fallopian tube provides the environment for early embryo growth, a process which is influenced by insulin-like growth factors (IGFs) in the tubal fluid. Whether the bioavailability of tubal IGFs is modulated by locally produced IGF-binding protein (IGFBP-1) is not clear. An explant culture system from human Fallopian tube mucosa was, therefore, developed enabling the potential for IGFBP-1 production by this tissue to be examined directly. Initial characterization of the system established that the explants maintained responsiveness to steroids. Thus, oviduct-specific glycoprotein production, a major product of the oviduct in vivo, continued to be made via an estrogen-sensitive pathway in the culture. The presence of mRNA for IGFBP-1 was established within the explants by the use of quantitative RT-PCR and IGFBP-1 protein was measured by enzyme-linked immunosorbent assay. Although insulin and estradiol had no consistent effect on IGFBP-1, addition of progesterone had a significant inhibitory effect on IGFBP-1 production, both at the mRNA and protein levels. A dose-range of progesterone revealed an incremental inhibitory effect of progesterone on IGFBP-1 output (maximal effect, 25-50 nmol/l), consistent with physiological inhibition of this process during the luteal phase. We suggest that progesterone might, therefore, play a role in controlling the bioavailability of IGFs to the embryo during early development within the Fallopian tube.

Adult↗

PubMed2004

Beta cell differentiation during early human pancreas development.

Understanding gene expression profiles during early human pancreas development is limited by comparison to studies in rodents. In this study, from the inception of pancreatic formation, embryonic pancreatic epithelial cells, approximately half of which were proliferative, expressed nuclear PDX1 and cytoplasmic CK19. Later, in the fetal pancreas, insulin was the most abundant hormone detected during the first trimester in largely non-proliferative cells. At sequential stages of early fetal development, as the number of insulin-positive cell clusters increased, the detection of CK19 in these cells diminished. PDX1 remained expressed in fetal beta cells. Vascular structures were present within the loose stroma surrounding pancreatic epithelial cells during embryogenesis. At 10 weeks post-conception (w.p.c.), all clusters containing more than ten insulin-positive cells had developed an intimate relationship with these vessels, compared with the remainder of the developing pancreas. At 12-13 w.p.c., human fetal islets, penetrated by vasculature, contained cells independently immunoreactive for insulin, glucagon, somatostatin and pancreatic polypeptide (PP), coincident with the expression of maturity markers prohormone convertase 1/3 (PC1/3), islet amyloid polypeptide, Chromogranin A and, more weakly, GLUT2. These data support the function of fetal beta cells as true endocrine cells by the end of the first trimester of human pregnancy.

Animals↗

PubMed2003

Progesterone up-regulates WT1 mRNA and protein, and alters the relative expression of WT1 transcripts in cultured endometrial stromal cells.

OBJECTIVE: To determine the change in expression of the Wilms tumor suppressor gene product, WT1, by progesterone alone in endometrial stromal cell culture and to study its relationship with prolactin, a marker of decidualization. In addition, to examine the change in ratio of WT1 isoforms with and without exon 5 message. METHODS: Endometrial biopsies were taken from eight patients who had hysterectomy. Stromal cells were isolated and cultured in the presence of progesterone alone (12 days) or progesterone and 8-bromo-cyclic adenosine monophosphate (cAMP) (6 days). RNA was extracted from cells, and reverse transcription, real-time polymerase chain reaction (PCR), and conventional PCR were done to analyze WT1 mRNA expression. Immunocytochemistry was performed on equivalent cells to study WT1 protein expression. Decidualization was identified by increased prolactin concentrations in the media and immunocytochemical markers IGFBP-1 and collagen IV. RESULTS: Reverse transcription and real-time PCR revealed a significant increase in WT1 mRNA with increasing progesterone concentrations when decidualization was occurring (n = 6, P =.002). Increasing progesterone concentrations also increased the proportion of the WT1 transcript containing a 17-amino-acid insert (+ exon 5 expression); changes in WT1 exon 5 expression have been shown to be involved in control of proliferation and differentiation. Significant correlations between WT1 message and prolactin existed at physiologic progesterone concentrations (6.25, 12.5, 25, and 50 nM; P <.05) until prolactin concentrations reached a plateau at 100 nM. At concentrations of progesterone alone (> 25 nM) and progesterone with 8-bromo-cAMP, WT1 protein was localized to the nuclei of many of the decidualized stromal cells. CONCLUSION: The changing expression of WT1 isoforms in endometrial stromal cells caused by progesterone may be important for differentiation into the decidualized phenotype.

8-Bromo Cyclic Adenosine Monophosphate↗

PubMed2002

Elastin distribution in the myometrial and vascular smooth muscle of the human uterus.

Magnetic resonance imaging and transvaginal ultrasonography in women of reproductive age suggest that the myometrium consists of inner and outer layers. It was hypothesized that these structural and functional differences in the myometrium might be associated with a variation in elastin distribution. Fifty-one hysterectomy specimens representing all phases of the normal menstrual cycle were studied by immunocytochemistry, orcein staining and image analysis. Elastin was present within the outer myometrial smooth muscle, but was less widely distributed in the inner smooth muscle. Immunoreactivity and staining were observed in the myometrial arteries and arterioles and within the basal portions of endometrial arterioles. Elastin was also present in perivascular tissue, particularly near the large vessels. More extravascular (i.e. perivascular and smooth muscle) elastin was present in the outer myometrium in all cases, although no distinct layering was observed. Semi-quantitative analysis of the elastin distribution in 11 full thickness specimens demonstrated a decreasing gradient from outer to inner myometrium rather than distinct layering. Contrary to previous reports, these data suggest that the external region of the myometrium is more elastic than the inner region and that elastin is found throughout the arteriolar tree of the human uterus.

Elastin↗

PubMed2001

The levonorgestrel intrauterine system: the benefits of reduced bleeding.

The levonorgestrel intrauterine system (LNG-IUS) offers a new therapeutic concept that combines a highly efficient contraceptive with a treatment that reduces menstrual blood loss in both normal women and those with menorrhagia. Initially developed to decrease the risk of expulsion of the intrauterine contraceptive device by reducing myometrial contractility, recent clinical studies have shown that the LNG-IUS provides excellent contraception without many of the adverse effects associated with the conventional intrauterine contraceptive device. The main mechanism of action of the LNG-IUS appears to be at the level of the endometrium, where the high dose of local progestogen causes decidualization, epithelial atrophy and direct vascular changes. Whilst some women experience systemic hormonal effects, circulating concentrations of levonorgestrel are low in comparison to those seen after the levonorgestrel progestogen-only pill. The LNG-IUS results in a dramatic reduction in menstrual blood loss. In turn, this has led researchers to investigate the LNG-IUS as an alternative to surgery for the treatment of dysfunctional uterine bleeding, uterine fibroids and adenomyosis. The system has also been used as a means of delivering progestogen for endometrial protection in postmenopausal hormone replacement regimens. The main side-effect of the LNG-IUS is irregular breakthrough bleeding. This is most common in the first 6 months after insertion. Detailed counselling is crucial to explain this anticipated effect, in order to reduce unnecessary discontinuation of treatment. After 6 months' treatment with the LNG-IUS, 20% of women become amenorrheic, rising to 50% after 5 years. Again, it is important to explain that this is an expected phenomenon, that it is not related to disorders of the hypothalamic-pituitary-ovarian axis, and that this 'bleed-free' status might indeed be viewed as a positive feature in its own right.

Administration, Intravaginal↗

PubMed2000

Measurements of the dielectric properties of peripheral blood mononuclear cells and trophoblast cells using AC electrokinetic techniques.

The separation of trophoblast cells from the maternal circulation could provide a valuable diagnostic tool for prenatal diagnosis of genetic abnormalities. This has been attempted using antibody methods, but due to non-specificity of the antibodies, maternal cell contamination remains a problem. We have investigated the potential of dielectrophoretic separation methods as a means of isolating trophoblast cells from mixed peripheral blood mononuclear cells. To determine the potential of this method the dielectric properties of trophoblast cells and mixed peripheral blood mononuclear cells were measured using dielectrophoretic crossover and single cell electrorotation methods. Both dielectrophoretic crossover data and electrorotation data gave an average specific membrane capacitance of the peripheral blood mononuclear cells of 11.5 mF m(-2). Trophoblast cells prepared using three different methods had a higher average specific membrane capacitance in the range 13-18 mF m(-2). The differences in capacitance between the cell types could be exploited as the basis of an AC electrokinetic-based system for the separation of trophoblast cells from peripheral blood mononuclear cells.

Cell Membrane↗

PubMed2000

Spatially regulated differentiation of endometrial vascular smooth muscle cells.

Angiogenesis within the human endometrium involves the development of arterioles and elaboration of a capillary network. It was postulated that maturation of these arterioles involves a spatially regulated process of vascular smooth muscle cell (VSMC) differentiation. The endometrial vascular tree was therefore examined immunohistochemically for evidence of longitudinal and radial gradients of VSMC phenotype. Twenty-three hysterectomy specimens and 15 first trimester decidual tissues were studied. Five cytoskeletal markers (alpha and gamma-smooth muscle (sm) actin, sm myosin, desmin, vimentin), three endothelial markers (CD31, CD34, factor VIII related antigen) and two steroid receptors (oestrogen and progesterone) were detected immunohistochemically. alpha-sm actin was present throughout the wall of basal arterial segments and extended longitudinally towards the endometrial surface. Sm myosin expression was more restricted longitudinally and radially within in the vascular tree. The expression of gamma-sm actin was even more restricted than myosin. In first trimester decidua, however, gamma-sm actin was widely distributed within the wall of spiral arteries that were not invaded by trophoblast. Oestrogen and progesterone receptors were present in peri-vascular stromal cells but absent from vascular smooth muscle and endothelium. Endometrial VSMC differentiation involves a progressive increase in cytoskeletal complexity and occurs in a spatially regulated fashion.

Actins↗

PubMed2000

The long term health consequences of polycystic ovary syndrome.

Women with polycystic ovary syndrome have both insulin resistance and beta cell dysfunction. Consequently, they are at increased risk of developing diabetes and cardiovascular disease. Women with polycystic ovary syndrome present to clinicians at a young age and as such offer a unique opportunity to identify insulin resistant patients at an early stage. This enables the modification of risk factors and diagnosis of diabetes before the onset of macro- and micro-vascular symptoms. Increased emphasis should thus be placed on long term risk management and diabetic screening with advice on smoking, exercise and, if appropriate, weight loss. Where possible drugs that exacerbate insulin resistance should be avoided and consideration should be given to the use of insulin sensitising agents, particularly in the obese.

Diabetes Mellitus, Type 2↗

PubMed2000

A randomised comparison and economic evaluation of laparoscopic-assisted hysterectomy and abdominal hysterectomy.

OBJECTIVES: To determine the safety, cost effectiveness and effect on quality of life of laparoscopic-assisted vaginal hysterectomy (LAVH) compared with total abdominal hysterectomy (TAH) in the management of benign gynaecological disease. DESIGN: Randomised controlled trial and economic evaluation. SETTING: Three hospitals in the West of Scotland. PARTICIPANTS: Two hundred women scheduled for an abdominal hysterectomy for benign gynaecological disease. MAIN OUTCOME MEASURES: Conversion rate of LAVH to TAH, complication rates, NHS resource use and costs, quality of life using EuroQol 5 D visual analogue scale, and achievement of milestones. RESULTS: The overall incidence of operative complications was 14% in the TAH group and 8% in the LAVH group, with an 8% conversion rate. Length of operation was significantly greater in the women having LAVH at 81 +/- 30 min vs 47 +/- 16 min (P < 0.001). There was no difference in analgesic requirements between the groups although there was a significantly shorter hospital stay for those having LAVH. The rate of post-surgery recovery, satisfaction with operation and quality of life at four weeks post-operative were similar in the two groups of women. LAVH was significantly more expensive than TAH and remained more expensive for all but the most extreme scenario. CONCLUSIONS: This study demonstrates that despite the decreased length of hospital stay, LAVH is more expensive than TAH. In addition, recovery following operation and patient satisfaction were not affected by the route chosen. It is unlikely that LAVH represents an efficient use of NHS resources.

Adult↗

PubMed1999

Medical management of dysfunctional uterine bleeding.

Complaints of excessive menstrual bleeding (menorrhagia) have a substantial impact on gynaecological services and in most cases no organic pathology is identified. Up to 50% of women who present with menorrhagia have blood losses within the normal range. Medical therapy is indicated for patients who do not wish surgery, or for whom surgery is unsuitable. Nonsteroidal anti-inflammatory drugs and tranexamic acid offer a simple therapy to be taken during menses, with reductions in menstrual blood loss (MBL) of 25-35% and 50% respectively. Danazol and the gonadatrophin-releasing hormone analogues are highly effective, but their side-effects make them suitable only for short-term use. The combined oral contraceptive pill and the levonorgestrel intrauterine system give reductions in MBL of 50% and 80%, with additional contraceptive cover. Cyclical progestogens are the most commonly prescribed therapy in the United Kingdom but they are ineffective for the management of ovulatory menorrhagia unless taken at high doses (10-15 mg daily) for 3 weeks out of 4.

Anti-Inflammatory Agents, Non-Steroidal↗

PubMed1999

Effects of the insulin sensitizing drug metformin on ovarian function, follicular growth and ovulation rate in obese women with oligomenorrhoea.

Hyperinsulinaemic insulin resistance is commonly associated with hyperandrogenaemia, and menstrual dysfunction. The aim of this study was to examine the effects of the insulin sensitizing drug, metformin, on ovarian function, follicular growth, and ovulation rate in obese women with oligomenorrhoea. Twenty obese subjects with oligomenorrhoea [polycystic ovarian syndrome; (PCOS)] were observed longitudinally for 3 weeks prior to and for 8 weeks during treatment with metformin (850 mg twice per day). Fifteen patients completed the study. The frequency of ovulation was significantly higher during treatment than before treatment (P = 0.003). A significant decline in both testosterone and luteinizing hormone concentrations was recorded within 1 week of commencing treatment. Patients with elevated pretreatment testosterone concentrations showed the most marked increase in ovulation rate (P < 0.005), and significant reductions in circulating testosterone from 1.02 to 0.54 ng/ml (P < 0.005) after only 1 week of treatment. However, the sub-group with raised fasting insulin showed less marked changes, and the sub-group with normal testosterone concentrations showed no effect of treatment. Metformin had a rapid effect upon the abnormal ovarian function in hyperandrogenic women with PCOS, correcting the disordered ovarian steroid metabolism and ovulation rate; however, there appeared to be no effect in cases where the circulating androgen concentration was normal.

Adult↗

PubMed1999

Expression of intercellular adhesion molecules ICAM-1 and ICAM-2 in human endometrium: regulation by interferon-gamma.

The purpose of this study was to localize intercellular adhesion molecule (ICAM)-1 and ICAM-2 in human endometrium and myometrium throughout the menstrual cycle, and to determine whether the expression of these molecules is regulated by interferon (IFN)-gamma. ICAM-1 and ICAM-2 distribution was examined in endometrial biopsies by immunocytochemistry, and Northern blotting was used to quantify ICAM-1 and ICAM-2 mRNA expression in isolated endometrial glands. Stromal fibroblast cultures were exposed to IFN-gamma and the effect on expression of ICAM-1 and ICAM-2 was determined by immunocytochemistry and Northern blotting. ICAM-1 was localized in vivo to the apical surface of the glandular epithelium, the vascular endothelium and endometrial stromal cells throughout the menstrual cycle. Stromal expression of ICAM-1 was up-regulated in menstrual specimens. Northern blotting confirmed the presence of ICAM-1 mRNA in isolated endometrial glands. The expression of ICAM-1 antigen and message was increased in stromal cell culture after incubation with IFN-gamma in a time-dependent manner, suggesting that this cytokine stimulates the expression of ICAM-1 in the endometrial stroma. ICAM-2 antigen expression was restricted to the vascular endothelium. ICAM-2 mRNA was absent in endometrial glands. The widespread distribution of ICAM-1 in human endometrium suggests that this molecule is involved in the process of menstruation, the functioning of glands, blood vessels and stroma, and in regulating leukocyte trafficking into the tissue. ICAM-2 is restricted to the vascular endothelium where it might modulate leukocyte invasion of the stroma and myometrial connective tissue.

Antigens, CD↗

PubMed1999

Myometrial constitutive nitric oxide synthase expression is increased during human pregnancy.

Nitric oxide (NO), derived from L-arginine by the action of nitric oxide synthase (NOS), is a mediator of many diverse biological activities, including vasodilation, neurotransmission and inhibition of platelet adhesion. A role for NO in the maintenance of rat and rabbit pregnancy is supported by a variety of studies. A recent study in women demonstrated that myometrial inducible NOS (iNOS) expression was greater in the early third trimester than either the late third trimester or in the non-pregnant condition, suggesting that increased iNOS expression is involved in the maintenance of human pregnancy. Constitutive NOS (cNOS) expression was not determined. The aim of this study was to compare constitutive NOS (both eNOS and bNOS) expression in the human non-pregnant uterus, preterm pregnant uterus (25-34 weeks gestation) and term pregnant uterus (>37 weeks gestation) using immunohistochemistry and Western blotting. Preterm pregnant samples were taken from women with a variety of pathologies necessitating early delivery. We found that eNOS and bNOS protein concentrations were greater in the preterm pregnant myometrium than non-pregnant myometrium. eNOS, but not bNOS, protein concentration was lower in myometrial samples obtained at term compared with those obtained preterm. We conclude that the constitutive isoforms of NOS are also up-regulated in human pregnancy and may play a role in the maintenance of myometrial quiescence.

Blotting, Western↗

PubMed1999

Leukocytes infiltrate the myometrium during human parturition: further evidence that labour is an inflammatory process.

Inflammatory mediators in the cervix, placenta and fetal membranes play a crucial role in human parturition. The aim of this study was to determine whether the upper and lower segments of the myometrium are infiltrated by inflammatory cells during pregnancy and parturition. Myometrial biopsies were obtained from non-pregnant women, and pregnant women at term before and after the onset of spontaneous labour. Subpopulations of inflammatory cells were identified using immunocytochemistry. The intercellular adhesion molecules, 1 and 2, platelet endothelial cell adhesion molecule, vascular cell adhesion molecule and E-selectin were immunolocalized to investigate their involvement in leukocyte accumulation. Histological analysis demonstrated that inflammatory cells, predominantly neutrophils and macrophages, infiltrate human myometrium during spontaneous labour at term. The infiltrate is predominant in the lower uterine segment but is also present in the upper segment. Increased expression of E-selectin was found on the vascular endothelium of biopsies obtained during labour, suggesting a role for this molecule in the accumulation of leukocytes. These results suggest that inflammatory cell infiltration is part of the physiological mechanisms that occur in the myometrium during parturition. Further understanding of this process may suggest new strategies aimed at preventing preterm delivery.

Cell Adhesion Molecules↗

PubMed1998

Randomised trial of nitric oxide donor versus prostaglandin for cervical ripening before first-trimester termination of pregnancy.

BACKGROUND: Vaginal administration of the nitric oxide donor isosorbide mononitrate can induce effective ripening of the human cervix. We investigated whether this drug is associated with fewer side-effects than prostaglandins when used to ripen the cervix before first-trimester surgical termination of pregnancy, and assessed whether the extent of cervical ripening it induces is clinically sufficient. METHODS: 66 primigravid women scheduled for surgical termination were assigned to receive before surgery, per vaginam, isosorbide mononitrate 40 mg or 80 mg, or the prostaglandin analogue gemeprost 1 mg. The primary measured outcome was onset of new symptoms before termination of pregnancy. FINDINGS: More women remained symptom-free after isosorbide mononitrate than after gemeprost (28/44 [64%] vs 3/22 [14%], p<0.005). Pretreatment with gemeprost resulted in abdominal pain in 73% of women and vaginal bleeding in 32% compared with 3% and 0%, respectively, after isosorbide mononitrate, whereas, more women developed headache after isosorbide mononitrate (27%) than after gemeprost (0%). Cervical resistance and measured intraoperative blood loss were lowest after pretreatment with gemeprost. The measured cervical resistance and intraoperative blood loss with either dose of isosorbide mononitrate did not differ from those in a comparison group of 22 parous women not in the randomised trial. INTERPRETATION: Pretreatment with isosorbide mononitrate to ripen the cervix before first-trimester termination of pregnancy is associated with fewer side-effects than gemeprost treatment and adequately decreases cervical resistance. Isosorbide mononitrate could be used as an alternative to gemeprost for this indication.

Abortifacient Agents, Nonsteroidal↗

PubMed1998

Should sperm donors be paid? A survey of the attitudes of the general public.

Gamete donation in assisted reproduction is an accepted treatment option for certain infertile couples. Traditionally, men donating spermatozoa have been paid a nominal fee, whilst women donating oocytes have not. The issue of payment for sperm donors has recently attracted attention following the Human Fertilisation and Embryology Authority's (HFEA) suggestion that such payment may be withdrawn. Prior to the final meeting of the HFEA working party which is examining this issue, here we report the results of a survey designed to solicit opinion on whether sperm donors should be paid, to identify social or other factors which influence this opinion, and to examine the influence of financial incentive on potential donors. We surveyed 717 individuals in three distinct groups: the general public, students (potential donors), and infertility patients (potential recipients). The majority of the potential donor group (students) was in favour of paying sperm donors, as were infertility patients. In contrast the general public was not. The opinion of the general public on this issue was influenced by their prior knowledge of whether donors were paid: those of the general public favouring the payment of sperm donors had a prior awareness that such payments were made. Although not in favour of paying sperm donors, the general public overwhelmingly approved of the use of donated spermatozoa for the treatment of infertile couples, and thought that ways should be sought to increase the availability of donor spermatozoa for the treatment of infertility and for research purposes. Within the potential donor group (students), the majority indicated that financial reward was an important factor which would influence their decision to donate spermatozoa. As the majority of both the potential recipients and potential donors feels that sperm donors should be paid, perhaps the views of these groups should carry significant weight when the decision whether or not to withdraw payment is taken. This is especially the case in view of the fact that the majority of the general public is in favour of the use of donated spermatozoa for the treatment of infertile couples.

Biomedical Research↗

PubMed1998

Endothelin receptor expression in human decidua.

The endothelins are signalling peptides that act via two receptors, ET(A) and ET(B). In the human endometrium, endothelin receptors have been demonstrated in glands and stroma and have been shown to vary during the course of the menstrual cycle. The present study was undertaken to determine whether or not expression of endothelin receptors changes during pregnancy or after administration of exogenous progestagens. The expression of the receptors was correlated with the appearance of basement membrane components during decidualization of the endometrial stroma. Decidual specimens (n = 15) were obtained during the first trimester of pregnancy and 10 at term. Sixteen pairs of endometrial biopsies were obtained from women with menorrhagia before and after exposure to exogenous progestagens. A total of 15 hysterectomy specimens were used as controls for the expression of stromal basement membrane proteins in the absence of decidualization. Autoradiography was carried out with selective ligands for ET(A) ([125I]-PD 151242) and ET(B) ([125I]-BQ3020). The distribution of ligand binding was then compared with the distribution of laminin alpha2 light chain and collagen IV. ET(A), ET(B), laminin alpha2 light chain, and collagen IV were expressed in stromal decidual cells in the first trimester of pregnancy. ET(B) was also found on endometrial glandular epithelium. Quantitative macro-autoradiography and multiple regression analysis demonstrated a highly significant positive correlation (P < 0.001) between expression of ET(B) and laminin alpha2 light chain. In the third trimester qualitative examination suggested a reduction of ET(A) in the stroma. Progestagen-induced decidua exhibited a similar pattern to that found in first trimester decidua. This study has demonstrated up-regulation of ET(B) during the progesterone-dependent process of decidualization and suggests a paracrine or autocrine role for endothelins in the decidua.

Abortion, Induced↗