Days Of Progesterone Treatment Research Articles

#360 : Twin Pregnancy After Step-Wise Cryopreservation and Thawing of Oocytes, Sperm and Blastocysts in the Case of Azoospermia: Case Report

CASE: Although twins born from freeze-thawed mature oocytes were first reported in Australia in 1986, oocyte cryopreservation was experimental before 2012. The success of oocyte cryopreservation was uncertain compared to sperm freezing. Since then, many studies have been conducted on preserving female fertility, but data on the results of oocyte cryopreservation in the case of male infertility are limited. Thus, we aimed to report a twin pregnancy after three steps of cryopreservation, freezing, and thawing of oocytes, sperm, and blastocysts. At 40 years of age, a woman returned to our center, where donated sperm can be used by women with the desire to get pregnant. As her partner was diagnosed with severe oligospermia, she had already undergone eight cycles of OPU (Oocyte Pick Up), three times with fresh ET (Embryo Transfer), and three with thawed ET, but failed to get pregnant. With a diagnosis of recurrent implantation failure, she decided to cryopreserve oocytes for fertility preservation while waiting for her partner to improve his gamete condition. A total of 20 oocytes cryopreserved at three clinics were stored for that purpose. However, she decided to use sperm cryopreserved for donation after getting a urologic recommendation as a candidate for receiving donor sperm. Fourteen of 20 thawed oocytes survived (70%) and were inseminated by ICSI (Intracytoplasmic Sperm Injection) using thawed sperm. Twelve were fertilized (75%) and had started their development to become good embryos at three days (50%). Among five cryopreserved embryos, three were at the cleavage, and two were at the blastocyst stage. Two blastocyst embryos were thawed on the sixth day of progesterone treatment after pretreatment with estradiol valerate. Two gestational sacs were confirmed via ultrasound. This case is the first report of a successful pregnancy using cryopreserved oocytes, sperm, and blastocysts in Korea.

P-511 Prolonging the time of vaginal progesterone supplementation does not improve pregnancy outcomes after day 6 blastocyst transfer

Abstract Study question Does the administration of vaginal progesterone for 6 days improve pregnancy outcomes when transferring day 6 blastocysts, as opposed to 5 days of progesterone treatment? Summary answer We observed similar pregnancy outcomes after 5 and 6 days of vaginal progesterone supplementation following day 6 blastocyst transfer in oocyte recipient cycles. What is known already Progesterone administration promotes the final phase of endometrial preparation for embryo transfer. However, the optimal duration of progesterone transformation still remains unknown. The implantation potential of blastocysts formed at different timepoints is also contentious, as blastocysts on day 6 have been linked to poorer clinical outcomes compared to their day 5 counterparts. It is unclear whether this effect stems from an intrinsic impaired implantation capacity of slow-developing blastocysts, or a displaced window of implantation (WOI). It has been hypothesized that 6 days of progesterone administration may improve clinical outcomes after frozen day 6 blastocyst transfer. Study design, size, duration Retrospective cohort study of oocyte recipients undergoing single day 6 blastocyst transfer, between January 2020 and December 2022. This study compared two groups: day 6 blastocysts transferred after 5 days of progesterone administration (n = 284) and day 6 embryo transfers performed after 6 days of progesterone administration (n = 69). Participants/materials, setting, methods Our study included oocyte recipients who underwent a single embryo transfer of a day 6 blastocyst and hormonal replacement treatment for endometrial preparation with vaginal external progesterone administration (800mg/24h) for either 5 or 6 days prior to embryo transfer. Outcomes were analyzed using unpaired t-test or Fisher’s test and logistic regression. Multivariate models were adjusted for oral or transdermal estrogen administration and endometrial thickness on the day of embryo transfer. P-values <0.05 were considered significant. Main results and the role of chance Mean maternal age was 43.5 years, while patients had a mean BMI of 25.1. Mean days of estrogen therapy prior to embryo transfer were 22.4, with 75.3% of patients using transdermal estrogen administration, and achieving a mean endometrial thickness of 9.6 mm on the day of transfer. Mean progesterone levels on the day of transfer were 11.9 ng/ml. Thirty-seven percent of the day 6 blastocysts were of high quality. None of the demographic or cycle characteristics were significantly different between the study groups. When considering outcomes of day 6 blastocyst transfers, we found no significant differences in biochemical (26.33% vs 20.13%, p = 0.343), clinical (22.06% vs 17.46%, p = 0.49) and ongoing (14.64% vs 9.52%, p = 0.41) pregnancy rates between 5 and 6 days of progesterone administration. Our adjusted analysis further corroborated these results. Limitations, reasons for caution The retrospective nature of the study and low number of transfers performed after 6 days of progesterone treatment warrant careful interpretation. This study only evaluated endometrial preparation by vaginal progesterone administration in oocyte recipients and cannot be extrapolated to other routes of progesterone administration or other patient populations. Wider implications of the findings Poorer reproductive outcomes associated with the transfer of day 6 blastocysts appear to be related to a reduced implantation capacity of slow-developing embryos rather than a displaced WOI due to rising progesterone. WOI appears wider than assumed, as prolonged progesterone transformation times had no effect on pregnancy outcomes. Trial registration number Not applicable

Multifactor Prediction of Embryo Transfer Outcomes Based on a Machine Learning Algorithm.

In vitro fertilization-embryo transfer (IVF-ET) technology make it possible for infertile couples to conceive a baby successfully. Nevertheless, IVF-ET does not guarantee success. Frozen embryo transfer (FET) is an important supplement to IVF-ET. Many factors are correlated with the outcome of FET which is unpredictable. Machine learning is a field of study that predict various outcomes by defining data attributes and using relevant data and calculation algorithms. Machine learning algorithm has been widely used in clinical research. The present study focuses on making predictions of early pregnancy outcomes in FET through clinical characters, including age, body mass index (BMI), endometrial thickness (EMT) on the day of progesterone treatment, good-quality embryo rate (GQR), and type of infertility (primary or secondary), serum estradiol level (E2) on the day of embryo transfer, and serum progesterone level (P) on the day of embryo transfer. We applied four representative machine learning algorithms, including logistic regression (LR), conditional inference tree, random forest (RF) and support vector machine (SVM) to build prediction models and identify the predictive factors. We found no significant difference among the models in the sensitivity, specificity, positive predictive rate, negative predictive rate or accuracy in predicting the pregnancy outcome of FET. For example, the positive/negative predictive rate of the SVM (gamma = 1, cost = 100, 10-fold cross validation) is 0.56 and 0.55. This approach could provide a reference for couples considering FET. The prediction accuracy of the present study is limited, which suggests that there may be some other more effective predictors to be developed in future work.

Optimal Duration of Progesterone Treatment before Cryopreserved-Thawed Embryo Transfer

Objective: To investigate the optimal duration of progesterone therapy before cryopreserved-thawed embryo transfer and its impact on clinical pregnancy and live birth rates. Methods: Five hundreds women undergoing cryopreserved-thawed embryo transfer were included in the study. These patients had a total of 500 embryos frozen on day 3 (n = 200), day 4 (n = 100), day 5 (n = 150) and day 6 (n = 50). Artificial endometrial preparation was successfully performed in all participants. If the endometrial thickness reached a minimum of 8 mm or in the presence of a triple-line view, the patients were divided into four different groups and each group into two subgroups according to the estimated duration of progesterone treatment to be used. Group 1 (n = 200): This group consisted of patients with day 3 embryo transfer. While 100 of 200 patients received embryo transfer after 3 days of progesterone treatment, the remaining 100 patients received embryo transfer after 4 days of progesterone treatment. Group 2 (n = 100): This group consisted of patients who underwent day 4 embryo transfer. While 50 of 100 patients had embryo transfer after 4 days of progesterone treatment, the remaining 50 patients received embryo transfer after 5 days of progesterone treatment. Group 3 (n = 150): This group consisted of patients who received day 5 embryo transfer. While 75 of 150 patients received embryo transfer after 5 days of progesterone treatment, the remaining 75 patients received embryo transfer after 6 days of progesterone treatment. Group 4 (n = 50): While 25 of 50 patients received embryo transfer after 6 days of progesterone treatment, the remaining 25 patients received embryo transfer after 7 days of progesterone treatment. The primary outcome measure of our study was to evaluate clinical pregnancy rate (CPR), ongoing pregnancy rate (OPR), live birth rate (LBR) and miscarriage rate per pregnancy. Results: Clinical pregnancy rates were found in 50 of 100 (50%) cases who were given progesterone for 3 days. Of the 100 cases who were given progesterone for 4 days, 40 clinical pregnancy was detected (40%). Both OPR and LBR were found to be significantly lower in patients who received 4 days of progesterone treatment compared to those given 3 days. The rates of miscarraige (9.09%) in patients who received progesterone treatment for 4 days were significantly higher than those who received progesterone for 3 days (5.8%). In Group 2 both OPR and LBR were found to be significantly lower in patients who received 5 days of progesterone treatment compared to those given 4 days. The rate of miscarraige (25.0%) was significantly higher in patients who received progesterone treatment for 5 days compared to those who received progesterone for 4 days (33.3%). When 75 patients in group III who underwent embryo transfer on the fifth day and received progesterone treatment for 5 days and 75 patients who were given progesterone treatment for 6 days were evaluated in terms of CPR, OPR and LBR the difference was statistically significant between the two gruops. When patients in group IV were evaluated in terms of CPR, OPR and LBR the difference was statistically insignificant. Conclusions: Extending the progestereone usage period one day before embryo transfer has been found beneficial in patients who have been transferred for only fifth day.

Control and induction of ovulation in cattle

The control and induction of ovulation in cattle are discussed with particular reference to use of progesterone-impregnated coils in heifers and beef cows. Progesterone treatment for 14 days was required to obtain precise onset of oestrus. With 7, 9 or 12 days of progesterone treatment a luteolytic agent in the form of a prostaglandin (PG) or oestradiol benzoate had to be used. Fertility was normal after treatment durations of 7, 9 or 12 days, but fertility after 14-day treatment requires further testing. The progesterone coil was not effective in maintaining luteal-phase levels of progesterone throughout a 12-day treatment and increasing the concentration of progesterone in the coil from 4 to 20% was not effective in elevating the progesterone concentrations in blood. When progesterone concentrations dropped below approximately 1.5 ng/ml the basal level of LH began to rise before removal of the coil. A 2-fold rise in the basal level of LH was observed following the removal of the progesterone coil. This early rise in LH was absent in cows which did not ovulate after they were given a 12-day progesterone treatment and GnRH 24-36 h after removal of coils to induce the main LH peak. Absence of this early rise suggests that frequency and amplitude of episodic LH release were inadequate in the post-partum anovulatory period. Ovariectomy in the early post-partum period was not followed by an abrupt LH release.

Short communication: Establishment and maintenance of donkey-in-mule pregnancy after embryo transfer in a non-cycling mule treated with oestradiol benzoate and long-acting progesterone

Female mules are considered as infertile; however, they could be used as recipients in interspecific embryo transfer. This study reports for the first time how it is possible to obtain the birth of a live Andalusian donkey foal after transfer a donkey embryo to a non-cycling mule. Two non-cycling mules were used as recipients, oestradiol benzoate was administered when donors showed oestrus and long-acting progesterone after ovulation. The mules also received long-acting progesterone every 7 days until 120 days of gestation. One embryo was collected from the two donor jennies and transferred to one of the mules after 5 days of progesterone treatment. Pregnancy was established and maintained after embryo transfer. The pregnant mule carried to term and delivered a live donkey foal after 375 days of pregnancy. In conclusion, non-cycling mules treated with oestradiol benzoate and long-acting progesterone can be successfully used as recipients of donkey embryos, which open new ways for the conservation of endangered donkey species.

Delayed implantation may be a cause of recurrent implantation failure

We report a rare case of delayed implantation of frozen-thawed embryo transfer in a hormone-controlled cycle due to delayed window of implantation (WOI). Synchronizing embryo growth with the endometrial hormonal environment is important for successful implantation. Initially, our patient underwent multiple unsuccessful endometrium-matched blastocyst transfers after five days of progesterone treatment. We found that day 3 embryo and two-day delayed blastocyst transfers were more successful than the normal blastocyst transfer. Finally she underwent two successful single embryo implants that resulted in pregnancies. We suggest that a delay in the WOI may have been the cause for the recurrent implantation failure.

Differential changes in luteinizing hormone secretion after administration of the investigational metastin/kisspeptin analog TAK-683 in goats

This study aimed to evaluate the hormonal and ovarian responses to the administration of a metastin/kisspeptin analog (TAK-683) under the endocrine environments of luteal and follicular phases in goats. Five estrous cycling goats received a prostaglandin F2α injection followed by 10 days of progesterone treatment by CIDR. The TAK-683 (35nmol) was intravenously administered (Hour 0) on 3 days after CIDR insertion (luteal phase condition; LC) and at 12h after CIDR removal (follicular phase condition; FC). Blood samples were collected at 10min (−2 to 6h), 2h (6–24h) or 6h intervals (24–48h). In the LC, small increases in the basal concentrations of LH were observed after TAK-683 administration from 0 to 6h, which were associated with an increase in estradiol concentration, followed by a surge-like release of LH with a peak at 12.5±1.0h (n=4) after TAK-683 administration. In the FC, a surge-like release of LH occurred immediately after TAK-683 administration with a peak at 6.0±3.5h (n=5), which was earlier than that in the LC (P<0.01). The peak concentration of estradiol did not differ between the two conditions, whereas the time interval from TAK-683 treatment to estradiol peak in the LC was longer than that in the FC (12.0±0.0 compared with 6.0±4.2h, P<0.05). These findings suggest that the timing of surge-like release of LH after TAK-683 administration is associated with blood estradiol concentration at the time of treatment.

Basal Insulin Requirements after Progesterone Treatment in a Type 1 Diabetic Pregnant Woman

We herein report the case of a 37-year-old type 1 diabetic pregnant woman treated with an insulin pump. Although the patient's glycemic control deteriorated following progesterone treatment for the prevention of preterm delivery and miscarriage, it was improved by adjusting the basal insulin rate on the days of progesterone treatment. Excess progesterone is known to impair both insulin sensitivity and secretion. The present case is the first report to evaluate deterioration of glycemic control induced by progesterone treatment and to determine the dose of insulin required in a type 1 diabetic pregnant woman whose insulin secretion was completely depleted.

Sickness behaviors following medial frontal cortical contusions in male rats

Behaviors associated with sickness (food consumption, weight maintenance, exploratory activity and grooming frequency) were examined on post-surgical days 1, 3, 5, 7 and 9 in male rats treated with progesterone (4 mg/kg) and/or vehicle. Rats with medial frontal cortex contusions showed reduced food consumption on days 1 and 3 ( p < 0.01), reduced weight maintenance on days 1, 3, 5, 7 and 9 ( p < 0.01), reduced grooming frequency on day 1 ( p < .01), and reduced exploratory activity on day 1 ( p < 0.01), after injury compared to sham rats. Contusion induced behaviors were not attenuated with 5 days of progesterone treatment ( p > 0.05). Progesterone did reduce lesion size at 9 days after injury ( p < 0.05). Our results suggest sickness behaviors occur after traumatic brain injury and that they might not respond to some neurosteroidal agents.

P-115: Value of transferring top quality embryos in frozen cycles

Freezing and storing of surplus embryos allows for a reduction in the number of embryos replaced in both fresh and frozen transfers (FET), thereby diminishing the risk of multiple pregnancies. Evidence showed that embryos of poor cleavage, uneven blastomeres and with increased fragmentation perform very poorly thus many centers do not freeze such embryos. This study objective was to compare implantation and pregnancy rates (IR and PR, respectively) following FET that had or not top quality embryos (TQE) Retrospective study. All records from 11/04 and 12/05 were reviewed. Data from 77 cycles with transferences of frozen embryos which were originally frozen on day 3 were included. Freezing solution included 1.5M 1,2-propanediol (PROH) in 0.1M sucrose in the classical slow-freezing protocol. Embryos were thawed by passing them through 3 consecutive solutions of decreasing concentrations of PROH and sucrose. The thawed embryos were thoroughly washed, cultured and transferred. Uterine transfer of thawed embryos was carried out on the fourth day of progesterone treatment. One to three embryos were transferred per patient depending upon the number and quality of embryos available for replacement. TQE was defined as embryos that had 7 and 9 cells with less than 5% fragmentation after 72 hours of embryo culture. For analysis the data was divided into two groups: Group A: with no TQE and Group B: with 1 or more TQE. All patients were submitted to supplementation of lutheal phase with micronized progesterone and estradiol. The pregnancies were confirmed by ultrasound after 28 days of the transference. Chi-square test was employed to compare qualitative variables, and Student’s t-test to compare quantitative variables. The significance level was set at P < 0.05. Four hundred and thirteen embryos were thawed and 224 (54%) were transferred; 133 in group A and 91 in group B. Maternal age and the number of frozen-thawed embryo transfers were similar in both groups. IR and PR were significantly greater in the group with TQE. Data shown in Table.Tabled 1 The data from this study suggest that transferring frozen-thawed TQE provides substantially greater chances of establishing PR. Nevertheless, these findings do not negate FET with poor quality embryos, but require a detailed patient information before consenting.

The treatment of OHSS with high dose of progesterone reduces the serum levels of IL-6

Ovarian hyperstimulation (OHSS) is the most common and dangerous complication of pharmacological induction of ovulation. It occurs with three grades according to the severity of symptoms underlying the clinical manifestation of the syndrome. The pathophysiology of this syndrome remains not well understood and consequently, in spite of the large number of therapies proposed, the treatment is argued. However, we have recently reported that the treatment with high doses of progesterone in severe OHSS is able to get ovarian shrinkage and the rapid disappearance of the clinical manifestations in a few days. It has been shown that in the OHSS is an increase of serum levels of IL-2, IL-6, IL-8 and TNFα. We tried to correlate the clinical effects of the treatments for OHSS, progesterone or albumin, and IL-6 behavior. Twenty patients with severe OHSS were randomly treated with high doses of progesterone (200 mg/day) or albumin. Blood samples were drawn in all patients before treatments started and after 4 days of therapy in both groups of patients. IL-6 was assessed by ELISA (Biosource, CA, USA). Data were reported in mean and standard deviation, and statistical analysis was performed using Student’s t-test. IL-6 was significantly reduced after 4 days of progesterone treatment with respect to the levels before treatment ( 13.1± 1.9; 7.3±1.3: P<0.01), whereas in patients treated with albumin, IL-6 did not show significant differences (12.9±1.9; 11.0±1.7: P>0.05). The treatment of OHSS with progesterone, other than improves the clinical features, also reduces the production of inflammatory substances.

Length of progesterone exposure needed to resolve large follicle anovular condition in dairy cows

Hypothalamic unresponsiveness to an estradiol surge appears to be an underlying cause of large follicle anovular condition (follicular cysts), but progesterone exposure for 7 days resolves this condition. In this study, dairy cows with induced (Experiment 1) or naturally occurring (Experiment 2) follicular cysts were treated for different times with progesterone. In Experiment 1, 16 of 26 cows (62%) were induced into anovulation by causing a GnRH/LH surge when no ovulatory follicle was on the ovary. Anovular cows ( n = 16) were assigned to one of four treatment groups ( 0, 1, 3, or 7 days of progesterone treatment) using an intravaginal, progesterone-releasing implant (CIDR). All anovular cows had low circulating progesterone concentrations before controlled internal drug releasing (CIDR) and greater concentrations that reached steady state (1.3 ± 0.1 ng/mL progesterone) by 3 h after CIDR insertion. Circulating progesterone decreased to basal concentrations by 4 h after CIDR removal. Cows were treated with 5 mg estradiol benzoate (EB) 12 h after CIDR removal. None ( n = 4) of the control cows (0 day) had an LH surge after EB. All of the 3 days (5/5) and 7 days (4/4) CIDR-treated cows had an LH surge following EB, but only one of the 1 day (1/3) CIDR-treated cows. Magnitude of the LH peak was similar in the 3 and 7 days cows. All cows treated for 7 days ovulated (4/4), whereas, ovulation occurred in only 3/5, 1/3, and 0/4 of the cows treated for 3, 1, and 0 day, respectively. The two cows in the 3 days group that did not ovulate had a normal LH surge, but these two cows had a smaller maximal follicle size than cows that ovulated. In Experiment 2, naturally anovular lactating dairy cows (24 of 248) were identified using weekly ultrasonography. All anovular cows grew follicles to >12 mm, with 54% (13 of 24) having follicles larger than ovular size (15–24 mm) and 33% (8 of 24) having follicles that would be considered cystic (>25 mm). Anovular cows were randomly assigned to CIDR treatment for 0, 1, or 3 days. All (7/7) of 3 days, 33% (3/9) of 1 day, and 25% (2/8) of control (0 day) cows ovulated by 1 week after CIDR removal. Thus, 3 days but not 1 day of progesterone exposure appears to be sufficient to reinitiate estradiol responsiveness of the hypothalamus.

A simple, inexpensive and effective artificial cycle with exogenous transdermal oestradiol and vaginal progesterone for the transfer of cryopreserved pronucleated human oocytes in women with normal cycles.

Supernumerary pronucleated stage oocytes (PN) are usually cryopreserved. PN are transferred in spontaneous, stimulated or artificial cycles. In this study, an artificial cycle with a transdermal therapeutic system was used for oestradiol release (Estraderm TTS 100) in combination with a targeted drug delivery system for vaginal progesterone release (Crinone 8%). Patients started transdermal 17beta-oestradiol treatment on cycle day 1. Only one clinical monitoring was necessary on day 14 for confirmation of satisfactory endometrial development and exclusion of ovulation by transvaginal ultrasound and endocrine determinations (oestradiol, progesterone and luteinizing hormone). Embryo transfer was performed on the third day of progesterone treatment (day 17). The first 25 cycles were recently completed in a prospective study; no cycles were cancelled due to ovulation or unsatisfactory endometrial development. In comparison with the previous protocol of embryo transfer in stimulated cycles in our clinic which required extensive ultrasound and endocrine monitoring, the pregnancy rate in these oestrogen- and progesterone-supplemented cycles was nearly twice as high (34.8%). Two pregnancies were even achieved with zygotes after micro-injection of frozen-thawed late spermatids extracted from testicular tissue (cryo-TESE). In these cycles, the Estraderm TTS 100/Crinone 8% protocol seems to be superior to stimulation protocols and even to other protocols reported so far for artificial cycles with exogenous oestradiol and progesterone treatment.

Progesterone stimulates pancreatic cell proliferation in vivo.

Treatment of cyclic and pregnant rats with progesterone stimulates cell proliferation within the islets of Langerhans. It was investigated whether this effect of progesterone depends on sex and/or the presence of the gonads or the presence of oestradiol. For this purpose, Silastic tubes containing progesterone were inserted s.c. in intact and gonadectomized male and female rats, and in gonadectomized female rats treated with oestradiol. After 6 days of progesterone treatment, rats were infused for 24 h with 5-bromo-2'-deoxyuridine (BrdU) and dividing cells were identified in pancreatic sections by immunostaining for BrdU. Progesterone treatment increased islet-cell proliferation in intact male and female rats (P < 0.05), but not in gonadectomized male and female rats or in gonadectomized female rats supplemented with oestradiol. Furthermore, in intact male and female rats, progesterone treatment also stimulated cell proliferation in extra-islet pancreatic tissue (P < 0.05). Identification of the proliferating cells, by double-immunocytochemistry, revealed that progesterone treatment stimulated proliferation of both alpha and beta cells within the pancreatic islets. In extra-islet pancreatic tissue, progesterone treatment stimulated proliferation in both duct (cytokeratin 20-immunoreactive) and non-duct cells. Progesterone treatment did not increase the number of single glucagon or insulin-containing cells outside the pancreatic islets, nor that of cytokeratin 20/insulin double-positive cells, suggesting that progesterone treatment did not stimulate differentiation of duct cells into endocrine cells. Progesterone treatment did not affect insulin responses to an i.v. glucose load (0.5 g/kg body weight). It is concluded that progesterone stimulates pancreatic cell proliferation indirectly; gonadal factor(s), not identical to oestradiol, is (are) probably involved.

Intrauterine infusion of ovine conceptus secretory proteins reduces prostaglandin F2α release without affecting endometrial oxytocin receptor concentrations

Abstract Chronically ovariectomized ewes were pretreated with progesterone and oestradiol to induce oestrus and randomly allocated into four treatment groups. Progesterone injections were given to Groups 1 and 2 on Days 1–12 and Groups 3 and 4 on Days 1–15. Ewes in Groups 2 and 4 were infused with conceptus secretory proteins (oCSP), via an intrauterine catheter, twice daily on Days 13–15. Ewes in Groups 1 and 3 were similarly infused, but with serum proteins (oSP). Endometrial oxytocin receptor (OTr) concentrations and oxytocin-induced 13,14-dihydro-15-keto-prostaglandin F 2α (PGFM) release were measured on Day 16. Progesterone concentrations in ewes receiving 12 days of progesterone treatment declined after Day 12, reaching a nadir on Day 14. In contrast, plasma progesterone concentrations remained elevated until Day 16 in ewes receiving the extended progesterone treatment. On Day 16, endometrial OTr concentrations were significantly higher in ewes given 12 days of progesterone treatment than in ewes given 15 days of progesterone irrespective of the presence of oCSP or oSP. Treatment with oCSP significantly decreased oxytocin-induced PGFM release in ewes given 12 days of progesterone treatment compared with those ewes receiving oSP infusions. The extended 15 day progesterone treatment resulted in a further decrease in oxytocin-induced PGFM release in both oCSP and oSP infused ewes. These data indicate that, in steroid treated ovariectomized ewes, intrauterine infusion of oCSP will reduce oxytocin-induced PGFM response but not OTr concentrations. Progesterone appears to play a dominant role in the regulation of OTr as well as oxytocin-induced PGFM release.

The effect of progesterone on the accumulation of leukocytes in the human endometrium

Our purpose was to determine the role of progesterone on the number and type of leukocytes found in human endometrium. Endometrial tissue was obtained from normally cycling women and from women receiving hormone replacement therapy for premature ovarian failure. All tissues were formalin fixed, sectioned, and stained with specific antibodies to leukocytes, T cells, B cells, and macrophages. Each tissue was also dated by means of published techniques. Quantitation was performed by counting all immunopositive cells in five high-powered fields. Data were compared by analysis of variance and Mann-Whitney U test. Leukocytes increased from 31.1 to 99.1 per high-powered field (p = 0.0001), and T cells increased from 10.9 to 20.4 per high-powered field (p = 0.001) after 12 days of progesterone treatment of women with ovarian failure. Normally menstruating women in the late luteal phase had similar concentrations. Neither B cells nor macrophages were found to increase with progesterone treatment. These data indicate that progesterone results in an increased leukocyte and T-cell concentration in human endometrium.

Oestrogen receptors in the preoptico-hypothalamic continuum: immunohistochemical study of the distribution and cell density during induced oestrous cycle in ovariectomized ewe.

Oestrogen plays a key role in the regulation of the endocrine and behavioural events associated with the oestrous cycle. It is important, therefore, to know the location of neurones receptive to this steroid and to know whether their distribution varies with the oestrous cycle. We have undertaken experiments to identify the location of oestrogen receptors (ER) within the preoptico-hypothalamic continuum of ovariectomized ewes submitted to a variety of different hormone replacement regimes which mimic the different stages of the oestrous cycle. We used a monoclonal antibody to ER and detected receptors with immunohistological methods in the non-vascular part of the organum vasculosum of the lamina terminalis, the lateral septum, the medial preoptic area, the supraoptic, suprachiasmatic and arcuate (ARC) nuclei, the ventromedial hypothalamus (HVM) and in the region close to the mamillari recess. ER neurones were scarce or absent from the anterior hypothalamus and the paraventricular nucleus. The density of ER staining in the HVM, but in no other localization, was found to be higher, and in a more lateral position, during the induced luteal phase (progesterone treatment) than during the follicular phase (7 days of progesterone treatment followed by oestradiol) or in the ovariectomized female. In all areas studied, except for the ARC, the apparent surface area of the nucleus in ER immunoreactive cells varied with hormonal treatment. These data, and especially those in the HVM, contribute towards our understanding of how steroids may act in the ovine to control sexual behaviour.

Prolonged progesterone treatment increases the concentration of uterine oxytocin receptors in ovariectomized ewes

The effect of prolonged progesterone treatment on the concentrations of endometrial oxytocin receptors (OTr) was studied in chronically ovariectomized ewes. The ewes were primed with progesterone and oestradiol-17β (E 2-17β) to induce oestrus (day of oestrus=Day 0) and then injected with graduated doses of progesterone, using vegetable oil as a vehicle, for 14, 16, 18 or 20 days. The control ewes were injected with the vehicle. The concentrations of OTr on the day of cessation of treatment were measured by a receptor binding assay. During the period of treatment, plasma progesterone concentrations rose above 1 ng ml −1 by Day 4 and remained above 2 ng ml −1 thereafter. Treatment with progesterone for 14 days significantly ( P < 0.01) reduced the concentrations of OTr in the endometrium compared with the control ewes. However, the concentrations of OTr were increased after 16 or more days of progesterone treatment. These results indicate that in ovariectomized ewes progesterone can exert a suppressive effect on the concentrations of endometrial OTr; however, prolongation of progesterone treatment would lead to OTr eventually becoming refractory to the suppressive effect of progesterone and an increase in the concentrations of OTr.

Ovine conceptus secretory proteins and bovine recombinant interferon alpha (1)-1 decrease endometrial oxytocin receptor concentrations in cyclic and progesterone-treated ovariectomized ewes.

A series of experiements was performed to determine whether proteins produced by the sheep conceptus (oCSP) during the time of maternal recognition of pregnancy or bovine recombinant interferon alpha 1-1 (brIFN) decrease oxytocin receptor concentrations in the endometrium of cyclic or ovariectomized progesterone-treated ewes. In experiment 1, cyclic ewes received intrauterine infusions of serum proteins (oSP), oCSP or brIFN on days 12, 13 and 14 of the oestrous cycle. Ewes then received an oxytocin challenge (1 microgram in 0.9% NaCl), and blood samples were taken just before and every 10 min for 1 h after the challenge; these were measured for 13,14-dihydro-15-ketoprostaglandin F 2 alpha (PGFM), the stable metabolite of prostaglandin F 2 alpha. Endometrial oxytocin receptor concentrations were then measured. The oCSP and brIFN treatments suppressed both endometrial oxytocin receptor concentrations and oxytocin-induced increases in PGFM concentrations. In experiment 2, ewes were ovariectomized and then pretreated with a fluorogestone acetate-releasing intravaginal device for 10 days followed by oestradiol (25 micrograms i.m. twice daily for 2 days). Ewes were then treated with progesterone (10 mg i.m. twice daily for 12 days). Ewes received intrauterine infusions of oSP, oCSP and brIFN on days 10, 11 and 12 of progesterone treatment. On the day after the last progesterone treatment, ewes were challenged with oxytocin and blood samples collected to measure PGFM. Endometrial oxytocin receptors were also measured. Treatment with oCSP, but not brIFN, suppressed endometrial concentrations of oxytocin receptor, and neither oCSP nor brIFN altered oxytocin-induced increases in PGFM concentrations.(ABSTRACT TRUNCATED AT 250 WORDS)