Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “PROGESTERONE”

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 181 records · Page 10Linked to original sources
PubMed1987

The use of a bovine plasma progesterone ELISA kit to measure progesterone in equine, ovine and canine plasmas.

A commerical kit designed to measure the concentration of progesterone in bovine plasma using an enzyme-linked immunosorbent assay (ELISA) has been assessed for measuring progesterone in the plasma of horses, sheep and dogs. Without validation, an immunoassay developed for progesterone in one species should not be used to measure progesterone in the plasma of other species. The kit was assessed by using the criteria of parallelism to a standard curve, the recovery of added progesterone, the correlation with an established radioimmunoassay and the detection of physiological change for each of the species tested. The ELISA kit proved to be acceptable for the analysis of progesterone in the plasma of each species, and in particular for the detection of the low concentrations found during the follicular phase and of the subsequent rise during the luteal phase of the oestrous cycle.

Animals↗
PubMed2004

Comparison of pregnancy outcomes of progesterone or progesterone + estradiol for luteal phase support in ICSI-ET cycles.

OBJECTIVE: To find out the effect of estradiol with progesterone for luteal phase support in IVF-ICSI cycles. MATERIALS AND METHODS: Patients were accepted for treatment in the ART unit of Selcuk University, Meram Faculty of Medicine, between January 2001 and March 2003. The study was done in a prospective manner. The age range of 252 women was 19-41 years and the total number of cycles was 310. All patients were treated with a long ovulation induction protocol. Patients were treated and divided into two groups in a randomized manner: group I used only 600 mg/day divided into three equal doses of micronized progesterone vaginally, and group II used transdermal estradiol 100 microg/day + 600 mg/day vaginal micronized progesterone. RESULTS: 310 ICSI cycles were carried out in 252 infertile couples between January 2001 and March 2003. From 22 of these cycles, oocytes were retrieved but no embryos were developed. In the remaining 288 cycles there were embryo transfers. All embryo development was achieved by ICSI treatment. In 148 out of 288 cycles, the luteal phase was supported only by vaginal micronized progesterone (group I). On the other hand, the remaining 140 cycles received vaginal micronized progesterone plus transdermal estradiol 100 microg/day (group II). The number of beta-hCG-positive results in group I and group II were 20 (13.5 %) and 54 (38.5%) respectively. CONCLUSION: Adding estradiol to progesterone for luteal phase support in ICSI-ET cycles may increase implantation and pregnancy rates.

Adult↗
PubMed1995

A randomized study comparing the efficacy of reducing the spontaneous abortion rate following lymphocyte immunotherapy and progesterone treatment versus progesterone alone in primary habitual aborters.

Presented herein is a randomized prospective study performed to evaluate the efficacy of the addition of lymphocyte immunotherapy (LI) to progesterone (P) therapy (LI/P) for the prevention of spontaneous abortion (SAB) in primary aborters with a history of three SABs. The incidence of intrauterine pregnancies in four cycles was 23 of 35 (65.7%) patients for LI/P vs. 14 of 31 (45.1%) patients treated with progesterone alone. SABs occurred in 6 of 23 (26.0%) LI/P-treated patients compared to 8 of 14 (57.1%) given progesterone alone. The mean number of previous abortions in both groups was 3.9. The mean age of the LI/P group was 34.1 vs. 33.6 years for the group treated with progesterone alone. These data could be interpreted to show that progesterone therapy and LI independently inhibit SAB or that LI/P acts synergistically to inhibit immune destruction. LI/P therapy was found to be more effective than progesterone therapy alone.

Abortion, Habitual↗
PubMed1975

[Composite microassays of plasma progesterone, 17alpha-OH-progesterone, estrone, 17beta-estradiol and estriol in normal adult women. II.Steroid patterns in normal pregnancy, labor and the puerperium (author's transl)].

Plasma progesterone, 17alpha-OH-progesterone, estrone, 17beta-estradiol and estriol in human normal pregnancy, labor and the puerperium were measured simultaneously with radioimmunoassay or competitive protein binding assay. The steroids were extracted from the sample plasma with diethyl either, and were separated through two steps of sephadex LH-20 microcolumn chromatography prior to the assays. From the beginning to the 25th week of pregnancy, a gradual rise in the levels of plasma progesterone was noted, followed by a steep increase toward term with a level of 150-250 ng/ml at the end of gestation. The levels of 17alpha-OH-progesterone during the 7th or 8th week of pregnancy were 2-3 ng/ml, which was above the normal range in the luteal phase, followed by a gradual decrease during 15-25 weeks of gestation. Thereafter, an increase toward term was seen with a mean level of 6-10 ng/ml in the 40th week. From the beginning to the end of pregnancy, plasma levels of estrone, 17beta-estradiol, and estriol increased from less than 0.5 ng/ml to 2-4 ng/ml, from 1-2.5 ng/ml to 6-10 ng/ml, and from less than 1 ng/ml to 6-10 ng/ml, respectively. The disappearance of steroids from maternal peripheral blood in the puerperium was rapid. The half time of progesterone, 17alpha-OH-progesterone, estrone, 17beta-estradiol, and estriol were 72 min, 68 min, 27 min, 27 min, and 48 min, respectively. Analysis of the interrelation between several kinds of steroids of pregnancy, labor, and the puerperium with simultaneous microassays will contribute to the clarification of some important physiological and pathological aspects of feto-placental-maternal functions and steroidogenic functions of the corpus luteum in pregnancy.

Estradiol↗
PubMed1976

Progesterone-binding globulin and testosterone-binding activity in guinea pig serum during pregnancy: relationship to progesterone and oestrogens.

Progesterone levels in serum have been determined throughout pregnancy in guinea-pigs by a competitive protein-binding technique, using pregnant guinea pig plasma protein as binding agent. The concentrations of this protein (progesterone-binding globulin, PBG) as well as the testosterone-binding activity (TBA) have been quantitated by means of equilibrium dialysis. In order to correlate these parameters to the endogenous oestrogen production, the urinary oestrogen excretion was recorded. The concentration of progesterone, PBG and TBA showed a sharp rise on days 14-18 of gestation, reaching a maximal level on days 30-44. The progesterone level thereafter declined significantly towards parturition, followed by a sharp drop post partum. PBG and TBA followed a similar course, the decline towards parturition, however, being non significant. Neither progesterone, PBG nor TBA were significantly correlated to the urinary oestrogen excretion. The concentration of PGB was remarkably high, amounting to 1-2 x 10(-5) M during most of the guinea pig pregnancy. This binding capacity generally exceeded the endogenous progesterone concentration by a factor of 20, as calculated on a molar basis. A mean of 64% of the binding sites was available for testosterone binding, corresponding to a free binding capacity of 400 mug testosterone per 100 ml.

Animals↗
PubMed1978

Pituitary responsiveness to LH-RH and TRH and the effects of progesterone or progesterone and oestradiol treatment in anoestrous sheep.

Pituitary responsiveness to 200 microgram synthetic LH-RH and to 10 microgram TRH was determined in anoestrous sheep before and after treatment for 3 weeks with progesterone (100 mg/day), or oestradiol (250 microgram/day) plus progesterone (100 mg/day). There was a marked decrease in pituitary responsiveness to LH-RH after progesterone (P is less than 0.01), or oestradiol plus progesterone (P is less than 0.01) treatments, and an increase in response to TRH after oestradiol plus progesterone (P is less than 0.01) treatment. The results demonstrate selective and simultaneous feedback effects of oestradiol and progesterone on pituitary responsiveness to two hypothalamic releasing hormones.

Anestrus↗
PubMed1997

High progesterone is related to effective human labor. Study of serum progesterone and 5alpha-pregnane-3,20-dione in normal and abnormal deliveries.

BACKGROUND: The role of progesterone levels during human labor is unclear. OBJECTIVE: To investigate serum concentrations of progesterone and 5alpha-pregnane-3,20-dione in normal and abnormal deliveries. METHODS: Venous and umbilical cord serum samples were collected from 108 parturient women. In a further 49 deliveries, arterial and venous umbilical cord sera were collected separately. The concentrations of progesterone and 5alpha-pregnane-3,20-dione were determined by radioimmunoassay. The delivery modes studied were: elective cesarean section; oxytocin-resistant dystocia; normal but induced delivery, and normal spontaneous delivery. RESULTS: Progesterone concentrations in maternal and umbilical serum were higher following normal labor than after dystocia (p<0.005) and elective cesarean section (p<0.005). The maternal and umbilical progesterone concentrations in dystocia and elective cesarean section were between 77-43% of those in normal labor. The concentrations did not vary between gestational weeks 37 and 42, within the different modes of delivery. The 5alpha-pregnane-3,20-dione serum concentration in the fetal compartment was twice that in the maternal compartment (p<0.001); its concentration in venous umbilical serum was higher than in corresponding arterial samples (p<0.001). No distinct differences in the 5alpha-pregnane-3,20-dione serum concentration were found with regard to parity or mode of delivery. CONCLUSION: High progesterone concentrations during parturition appear to be related to effective labor. The findings support results from in vitro experiments on human term myometrium.

5-alpha-Dihydroprogesterone↗
PubMed1990

Effects of progesterone and human chorionic gonadotrophin administration five days postinsemination on plasma and milk concentrations of progesterone and pregnancy rates of normal and repeat breeder dairy cows.

Treatment with a progesterone-releasing intravaginal device between days 5 and 12 after estrus elevated (p less than 0.05) plasma progesterone concentrations between days 6 and 8 in comparison with controls. Treatment with injectable progesterone (200 mg) on days 5, 7, 9 and 11 postestrus did not increase plasma progesterone concentrations over controls. The administration of 1500 IU human chorionic gonadotrophin (hCG) on day 5 after estrus resulted in a sustained increase (p less than 0.01) in plasma progesterone concentrations from day 8 until day 20 when measurements ceased. Pregnancy rates, as a result of artificial insemination (AI) at the pretreatment estrus, in these treatments (n = 12-14 each), were unaffected by any of the treatments and ranged from 57.1 to 75.0% at 45-60 days post-AI. In a field trial, of 36 repeat breeder cows treated with 1500 IU hCG 5.5 days after insemination, 47.2% were pregnant at 60 days, whereas 39.5% of saline-treated controls were diagnosed pregnant. Treatment with hCG significantly (p less than 0.05) increased milk progesterone concentrations over controls on days 14 and 20 after insemination.

Administration, Intravaginal↗
PubMed1985

Ovarian progesterone synthesis and content and plasma progesterone levels in adult mice treated with diethylstilbestrol neonatally.

Ovaries from 8-week-old female NMRI mice, treated with 5 micrograms diethylstilbestrol (DES) daily for the first 5 days after birth were studied for progesterone synthesis in vitro, using 3H-pregnenolone as precursor, and assayed for progesterone content using radioimmunoassay (RIA) technique. The plasma levels of progesterone were measured with RIA. These results were compared with those from control ovaries from females in different phases of the estrous cycle. Values for radioactivity representing 3H-progesterone were significantly higher after 1-hour incubation of ovarian homogenate from DES treated females than in homogenates of ovaries from any phase of the normal estrous cycle. The ovarian content of progesterone was similar in DES exposed ovaries and ovaries from females in proestrous or estrous but lower in DES ovaries than in diestrous ovaries. The plasma levels of progesterone were in the same range in DES treated females and diestrous females but higher in DES females than in estrous or proestrous females.

Animals↗
PubMed1995

Investigation of the efficacy of progesterone pessaries in the relief of symptoms of premenstrual syndrome. progesterone Study Group.

BACKGROUND: A variety of definitions have been applied to premenstrual syndrome. The severity of the syndrome is also variable. AIM: A study was undertaken to compare progesterone pessaries with placebo in the relief of symptoms of premenstrual syndrome. In this study the condition was characterized by a wide range of symptoms recurring in the late luteal phase but absent in the follicular phase (that is, the specific definition published by Dalton in 1953). METHOD: A multicentre, prospective, double-blind, randomized, parallel group study was undertaken by 45 general practitioners. Patients were deemed eligible after two prospective menstrual cycles of observation (selection phase) in which a precise definition of symptoms was applied. Patients were randomized to use either progesterone pessaries (400 mg twice a day) or matching placebo, by vaginal or rectal administration, from 14 days before the expected onset of menstruation until the onset of vaginal bleeding, for four consecutive cycles. Baseline data for the outcome variables were determined in the selection phase. The main outcome variables were changes in the severity (categorized as none, mild, moderate or severe) of each patient's most severe symptom, and in the average score of all the patient's symptoms characteristic of premenstrual syndrome. Spontaneous reports of adverse events were recorded. RESULTS: A total of 281 patients were screened for premenstrual syndrome; of these, 141 patients were randomized to treatment or placebo groups. Efficacy was evaluated in 93 patients. Reductions in the scores of the highest scoring, most severe, symptoms and in the average symptom score, were consistently observed in patients receiving progesterone pessaries and in those receiving placebo. The response to progesterone was greater than to placebo during each cycle; the differences were clinically and statistically significant. Adverse events were reported by 51% of patients in the progesterone treatment group and by 43% in the placebo group. Irregularity of menstruation, vaginal pruritus and headache were reported more frequently by patients taking active therapy. CONCLUSION: In this study, progesterone, given as pessaries by vaginal or rectal administration, was more effective than placebo in the relief of symptoms of premenstrual syndrome in a population of patients selected by strict entry criteria.

Adolescent↗
PubMed1978

The effect of progesterone analogues, naturally occurring steroids, and contraceptive progestins on hypothalamic and anterior pituitary delta4-steroid (progesterone) 5alpha-reductase.

The effects of a number of steroids on the conversion of progesterone to 5alpha-dihydroprogesterone by hypothalamic and pituitary progesterone 5alpha-reductase have been investigated. Using enzyme preparations from female rats and 3H-progesterone as substrate, 5alpha-reduced products (5alpha-dihydroprogesterone and 3alpha-hydroxy-5alpha-pregnan-20-one) were analyzed by reverse isotopic dilution analysis. The amount of total 5alpha-reduced products formed was compared in the presence and absence of the test steroid. Derivatives lacking the delta4 and/or the 3-keto moiety were without effect. Corticosterone had no effect. 16beta-Methylprogesterone inhibited progesterone 5alpha-reduction in both tissues by at least 65%, while the 2alpha-, 6alpha-, and 7alpha-methylated derivatives had lesser effects. 3-Oxo-4-pregnene-20beta-carboxaldehyde and 21-fluoroprogesterone were potent inhibitors. 17-Hydroxyprogesterone was a competitive inhibitor (substrate) with Ki's of 0.27 micrometer (pituitary) and 0.29 micrometer (hypothalamus). Medroxyprogesterone exerted little inhibitory effect. Of the 19-nor-steroids examined, only norethindrone appreciably inhibited the 5alpha-reduction. These results suggest that some natural delta4-3-ketosteroids can modify enzymatic activity. Also, inhibitory analogues may be useful for studies on the role of this 5alpha-reduction of progesterone.

3-Hydroxysteroid Dehydrogenases↗
PubMed2006

Plasma membrane destination of the classical Xenopus laevis progesterone receptor accelerates progesterone-induced oocyte maturation.

Xenopus laevis oocyte maturation is induced by the steroid hormone progesterone through a non-genomic mechanism initiated at the cell membrane. Recently, two Xenopus oocyte progesterone receptors have been cloned; one is the classical progesterone receptor (xPR-1) involved in genomic actions and the other a putative seven-transmembrane-G-protein-couple receptor. Both receptors are postulated to be mediating the steroid-induced maturation process in the frog oocyte. In this study, we tested the hypothesis that the classical progesterone receptor, associated to the oocyte plasma membrane, is participating in the reinitiation of the cell cycle. Addition of a myristoilation and palmytoilation signal at the amino terminus of xPR-1 (mp xPR-1), increased the amount of receptor associated to the oocyte plasma membrane and most importantly, significantly potentiated progesterone-induced oocyte maturation sensitivity. These findings suggest that the classical xPR-1, located at the plasma membrane, is mediating through a non-genomic mechanism, the reinitiation of the meiotic cell cycle in the X. laevis oocyte.

Animals↗
PubMed1986

Progesterone metabolism in T47Dco human breast cancer cells--II. Intracellular metabolic path of progesterone and synthetic progestins.

We show here that progesterone added to the medium of proliferating T47Dco human breast cancer cells is metabolized with a half life of 2-4h. The final metabolic product, 5 alpha-pregnan-3 beta,6 alpha-diol-20-one, (P-metabolite) is released into the medium. This structure suggested that the intracellular metabolism of progesterone involves the enzymes 5 alpha-reductase, 3 beta-hydroxysteroid dehydrogenase, and 6 alpha-hydroxylase. To investigate this pathway, the cells were incubated with a variety of potential substrates. In addition to progesterone, only precursors with the 5 alpha-configuration served as substrates for the enzymes leading to P-metabolite formation. Some precursors with a 5 beta-configuration were also metabolized by T47Dco cells. This metabolism reflected activity by either 3 beta-hydroxysteroid dehydrogenase and/or 6 alpha-hydroxylase but, in contrast to progesterone metabolism, the rates were different and the products were often mixtures. In T47Dco and MCF-7 human breast tumor cells, the reduction at C-3 followed by 6 alpha-hydroxylation, appear to be the major, and possibly only, route of progesterone metabolism. In contrast, preliminary data suggest that in normal human breast epithelial cells, this is not an exclusive route. Androgens are partially subject to the same metabolic enzymes, but synthetic progestins are not metabolized by T47Dco during an 18 h incubation.

3-Hydroxysteroid Dehydrogenases↗
PubMed1992

Effect of the progestagen R5020 (promegestone) and of progesterone on the uptake and on the transformation of estrone sulfate in the MCF-7 and T-47d human mammary cancer cells: correlation with progesterone receptor levels.

In the present study we have explored the actions of the progestagen R5020 (Promegestone: 17 alpha, 21-dimethyl-19-nor-pregna-4, 9-diene-3,20-dione) and progesterone on the uptake of [3H]estrone sulfate ([3H]E1S) and its conversion to estradiol (E2) by two hormone-dependent mammary cancer cell lines: MCF-7 and T-47D. R5020 or progesterone significantly decreased the uptake of [3H]E1 and its conversion to (E2). In the cells of the two lines, R5020 or progesterone (5 x 10(-6) M) decreased the E2 concentrations by 2-3 times in relation to the levels in untreated cells. E1S (1 x 10(-7) M) also increased expression of the progesterone receptor (PR) and both R5020 (5 x 10(-6) M) and progesterone (5 x 10(-6) M) blocked this stimulatory action of E1S in cells of both cell lines. As E2 is one of the main factors of cancerization in the breast and estrone sulfate is quantitatively the most important precursor of E2 in this tissue, the decrease of E2 by these progestagens could open new possibilities for the control of E2 in the breast cancer tissue.

Biotransformation↗
PubMed2004

Identification of a novel mechanism of NF-kappaB inactivation by progesterone through progesterone receptors in Hec50co poorly differentiated endometrial cancer cells: induction of A20 and ABIN-2.

OBJECTIVE: Nuclear factor kappa B (NFkappaB) is a strong anti-apoptotic factor, which is constitutively active in human endometrial cancer cells. Progesterone is the principal growth inhibitory hormone in the endometrial epithelium and promotes apoptosis. To identify the pathways through which progesterone controls NFkappaB function, we explored its genomic and non-genomic effects in endometrial cancer cells. METHODS: PR-negative Hec50co endometrial cancer cells were engineered to express high levels of the A or B isoform of PR (PRA or PRB) by adenoviral infection. Cells were treated with progesterone or vehicle alone, and RNA was isolated. Affymetrix microarrays were performed and transcriptional control of the genes of highest interest was confirmed by semi-quantitative RT-PCR. To assess the non-genomic effects of PR on inflammation associated with NF-kappaB, electromobility shift assays (EMSAs) were performed. RESULTS: Expression analysis demonstrated a significant effect of progesterone after 12- and 24-h treatment on several genes; in particular, A20 and ABIN-2 were induced through PRB. These factors bind in a complex and inhibit NFkappaB transcriptional activity. In addition, EMSAs revealed the complete inhibition of NFkappaB dimer binding to DNA by both PRA and PRB. CONCLUSIONS: Progesterone is the principal differentiating hormone in the endometrium. We have now identified several down-stream pathways of action, one of which is the control of genes involved in NFkappaB activity. The tumorigenic inflammatory and anti-apoptotic effects of NFkappaB are inhibited by progesterone/PRB through the transcriptional control of binding proteins A20 and ABIN-2. This pathway offers interesting targets for future therapeutic development.

Adaptor Proteins, Signal Transducing↗
PubMed2000

The size and/or configuration of the cycloalkane D' ring in pentacyclic progesterone derivatives are crucial for their high-affinity binding to a protein in addition to progesterone receptor in rat uterine cytosol.

[(3)H]labeled progesterone and a number of its 16alpha, 17alpha-cycloalkano derivatives with an additional three to six-membered D' ring were investigated for mutual competition and equilibrium binding to proteins from rat uterine cytosol. The interaction of all studied [(3)H]ligands with proteins was characterized by comparable affinity (K(d) in nM region) and apparent homogeneity in terms of affinity. At the same time, the concentrations of binding sites for ligands bearing 16alpha,17alpha cyclopentano, cyclohexano, or cyclohexeno substituents were several-fold higher than those for progesterone or 16alpha, 17alpha-cyclopropanoprogesterone. In mutual competition experiments, when [(3)H]progesterone or [(3)H]16alpha, 17alpha-cyclopropanoprogesterone were used, the curves of 'bound radioactivity-log of competitor concentration' for all compounds studied were parallel and corresponded to a model of 'one protein-two ligands.' However, when [(3)H]ligands with bulky 16alpha, 17alpha-substituents (with the possible exception of cyclohexene derivative) were used, competitive curves for various ligands had different appearances and fell into two groups. Parallel curves for derivatives with 5 or 6 carbons in D' ring described by a model of 'one protein-two ligands' formed the 1st group. The 2nd group comprised curves for progesterone or 16alpha, 17alpha-cyclopropanoprogesterone that had lower slopes and could be described by a model of 'two proteins-two ligands.' Taken together, the results suggest the presence in rat uterine cytosol, of a protein in addition to progesterone receptor capable of discriminating between ligands with no or small 16alpha, 17alpha-cycloalkano substituents and ligands with more bulky substituents.

Alkanes↗
PubMed1989

In vitro binding of progesterone, cronolone and medroxyprogesterone acetate to uterine progesterone receptors of sheep, rabbit and mouse.

Various aspects of the binding of the synthetic progesteongens, cronolone (9 alpha-fluoro-11 beta-hydroxy-17 alpha-acetoxypregn-4-ene-3,20-dione) and medroxyprogesterone acetate (6 alpha-methyl-17 alpha-acetoxypregn-4-ene-3,20-dione, MAP) to uterine cytosol progesterone receptors of the sheep, rabbit and mouse were studied, in an attempt to explain interesting species differences in the biological activity of these steroids. For the sheep, data for binding-site concentration, relative binding affinity (RBA), dissociation constant (Kd) and rates of association and dissociation indicate specific binding of cronolone to the progesterone receptor and these would seem to explain in part the high progestational activity of cronolone in this species. By contrast, with the mouse, there was only a low level of specific binding of cronolone and this appears to explain its inability to maintain pregnancy in this species. Results for the binding activity of cronolone in rabbit uterus were similar to those for the sheep and thus inability of cronolone to maintain pregnancy in the rabbit is not explained by a failure to bind the progesterone receptor. Species differences in binding to the progesterone receptor were also seen with MAP where the RBA, with respect to progesterone, was high in the sheep and rabbit and lower in the mouse. The results, however, do not relate directly to the progestational activity of MAP in these species. Overall, the data indicate that species differences in the binding activity of steroid receptors constitute one factor that causes species-dependent variation in biological responses to progestogens.

Animals↗
PubMed1996

Effects of interferon-tau and progesterone on oestrogen-stimulated expression of receptors for oestrogen, progesterone and oxytocin in the endometrium of ovariectomized ewes.

The effects of recombinant ovine interferon-tau (IFN-tau) and progesterone on oestrogen-stimulated expression of endometrial receptors for oestrogen (ER), progesterone (PR) and oxytocin (OTR) were determined in ovariectomized ewes. Cyclic ewes (n = 16) were ovariectomized and fitted with uterine catheters on Day 4 of the oestrous cycle (Day O, oestrous) and assigned randomly in 2 x 2-factorial arrangement to receive daily intrauterine injections of either recombinant ovine IFN-tau (roIFN-tau; 2 x 10(7) anti-viral units) or control proteins from Day 11 to Day 15 and 50 mg progesterone from either Day 4 to Day 10 (E-P) or Day 4 to Day 15 (E+P). All ewes received 50 micrograms oestradiol-17 beta on Days 13, 14 and 15 and were hysterectomized on Day 16. In control ewes, endometrial ER mRNA, PR protein and OTR density were greater in E-P- than E+P- treated ewes. In E-P ewes, roIFN-tau decreased oestrogen-stimulated increases in ER and OTR, but not PR expression compared with control ewes. In E+P ewes, endometrial ER mRNA and protein, PR mRNA and protein, and OTR levels were lower in roIFN-tau-treated ewes than control ewes. Immunoreactive ER and PR were absent in the endometrial luminal and superficial glandular epithelium of roIFN-tau compared with control ewes, but were present in the deep glandular epithelium and stroma regardless of steroid or protein treatment. These results indicate that progesterone affects oestrogen-induced increases in endometrial ER, PR and OTR expression in the PR+ deep glandular epithelium and stroma, whereas IFN-tau suppresses oestrogen-induced increases ER, PR and OTR expression in the PR- luminal and superficial glandular epithelium. These combined actions of IFN-tau and progesterone to suppress oestrogen-induced increases in endometrial OTR formation would prevent pulsatile production of luteolytic prostaglandin F2 alpha by the endometrium during early pregnancy.

Animals↗