Endogenous Progesterone Research Articles

Sugammadex Use for Reversal in Nonobstetric Surgery During Pregnancy: A Reexamination of the Evidence.

Sugammadex Use for Reversal in Nonobstetric Surgery During Pregnancy: A Reexamination of the Evidence.

Systematic Selection of Impurities, Development, and Validation of Related Substance Methods for Estradiol and Progesterone in a Combination Drug Product.

A kind of estrogen called estradiol is a female sex hormone that regulates several body processes. In hormone replacement therapy for women, the endogenous steroid progesterone is employed. The soft gel capsule medication, which contains a mix of 1 mg estradiol and 100 mg progesterone, is used to treat moderate to severe menopause symptoms, such as hot flashes, in women who have uteruses, as well as feelings of warmth in the face, neck, and chest. To establish the stability of drug products in accordance with the ICH Harmonized Tripartite Guideline, Stability Testing of New Drug Substances and Products (Q1A), this study aims to develop a reverse-phase chromatographic method, the necessary analytical methodology for identifying the drug degradation profiles. The procedures were optimized using a C18 column (250 × 4.6 mm, 5 µ) as the stationary phase and conventional solvents such as water-acetonitrile mixtures as the mobile phase. A quantification technique had been an HPLC combined with a UV/PDA and fluorescence detector. The developed methods for both estradiol and progesterone were capable of all components of each active individually by overcoming the extremely difficult challenges of a combination product with similar structural compounds, having 24 impurities in all, and having complex excipients used for soft gel formulation. The method has been successfully created, validated for use in compliance with regulatory specifications, and determined to be accurate, linear, specific, and stability-indicating in nature. To quantify the associated impurities of both actives in the presence of a highly complex matrix, the performance of the HPLC approach considerably possesses a higher degree of selectivity.

Insight into mitochondrial dysfunction mediated by clozapine-induced inhibition of PGRMC1 in PC12 cells

Clozapine is usually considered as the last resort for treatment-resistant schizophrenia (TRS). However, it shows limited efficacy in cognition improvement. Moreover, the metabolic side effects induced by clozapine can aggravate cognitive impairment, which is closely related to its neurotoxicity. Nevertheless, the mechanisms underlying clozapine’s neurotoxicity remain largely elusive. In this study, PC12 cells were simultaneously treated with different concentrations (0 μM, 10 μM, 20 μM, 40 μM and 80 μM) of clozapine and AG205 which functions as a blocking reagent of progesterone receptor membrane component 1 (PGRMC1). In addition, we examined the effect of PGRMC1 in clozapine-induced neurotoxicity through overexpressing or downregulating PGRMC1. Molecular docking and surface plasmon resonance (SPR) analysis indicated that clozapine and AG205 inhibited the binding of endogenous progesterone to PGRMC1. The results showed that high concentration of clozapine and AG205 induced a significant increase in cytotoxicity, reactive oxygen species (ROS) accumulation and mitochondrial membrane potential (MMP) collapse, all of which were worsened as concentration increases, while overexpression of PGRMC1 reverted the above toxic effect of clozapine on PC12 cells. Furthermore, clozapine and AG205 also downregulated the expression of PGRMC1, glucagon-like peptide-1 receptor (GLP-1R) and mitofusin2 (Mfn2). Interestingly, overexpression of PGRMC1 could revert these effects. Our data suggest that overexpression of PGRMC1 in PC12 cells prevents and restores clozapine-induced oxidative and mitochondrial damage. We propose PGRMC1 activation as a promising therapeutic strategy for clozapine-induced neurotoxicity to facilitate the relief of neuronal damage.

Hipersensibilidade ao progestogênio: relato de caso

Progestogen hypersensitivity is characterized by heterogeneous skin eruptions that cyclically aggravate during the luteal phase of the menstrual cycle, corresponding to a rise in progesterone levels. The clinical presentation is highly variable, with urticarial, angioedema, and eczematous lesions being prominent. Both endogenous progesterone and exogenous progestogens may represent an initial trigger. We report the case of a 42-year old woman who was unresponsive to all treatments, including progestin desensitization, that ultimately required bilateral oophorectomy to control her symptoms.

Endogenous progesterone in unexplained infertility: a systematic review and meta-analysis

PurposeTo investigate the possibility that altered actions of endogenous progesterone affect receptivity and contribute to unexplained infertility (UI).MethodsTwo authors electronically searched MEDLINE, CINAHL and Embase databases from inception to 6 July 2022 and hand-searched according to Cochrane methodology. We included all published primary research reporting outcomes related to endogenous progesterone in natural cycles in women with UI. Studies were assessed for risk of bias using a modified Newcastle–Ottawa Score or NHLBI Score. We pooled results where appropriate using a random-effects model. Findings were reported as odds ratios or mean differences.ResultsWe included 41 studies (n = 4023). No difference was found between the mid-luteal serum progesterone levels of women with UI compared to fertile controls (MD 0.74, − 0.31–1.79, I2 36%). Women with UI had significantly higher rates of ‘out-of-phase’ endometrium than controls. Nine out of 10 progesterone-mediated markers of endometrial receptivity were significantly reduced in women with UI compared to fertile controls (the remaining 1 had conflicting results). Resistance in pelvic vessels was increased and perfusion of the endometrium and sub-endometrium reduced in UI compared to fertile controls in all included studies. Progesterone receptor expression and progesterone uptake were also reduced in women with unexplained infertility.ConclusionsEnd-organ measures of endogenous progesterone activity are reduced in women with UI compared to fertile controls. This apparently receptor-mediated reduction in response affects endometrial receptivity and is implicated as the cause of the infertility. Further research is required to confirm whether intervention could overcome this issue, offering a new option for treating unexplained infertility.Trial registrationPROSPERO registration: CRD42020141041 06/08/2020.

Effects of norethisterone acetate on the performance of female racing Greyhounds

A comparison between the performance of spayed female racing Greyhounds and those suppressed with norethisterone acetate (NTA) was made. Previous work by the author has shown that the racing performance of spayed bitches is the same as that of entire bitches in anoestrus, i.e. spaying is just a permanent anoestrus. The aim was to assess any performance difference between suppression and anoestrus, and thus to determine the effect of norethisterone acetate on race performance. The study was designed as a retrospective case-control. Raceform data was obtained for female racing Greyhounds which had raced, and which were either spayed or suppressed with norethisterone acetate. Analysis showed that suppressed bitches run on average 0.049 to 0.061 s slower over 480 m (centralised models). Since endogenous progesterone (P4) has been linked with reduced race performance, it is logical that progesterone analogues like NTA should have a similar effect. It is likely that the depression in performance is dose-related, but not quantifiable with the current dataset.

P079Etonogestrel contraceptive implant users can experience breakthrough ovulation with only two weeks of exposure to a strong cyp3a inducer

<h3>Objectives</h3> Rifampin is a strong CYP3A inducer and the gold standard for evaluating CYP3A-mediated drug-drug interactions per the US Food and Drug Administration. We hypothesized that even a short course (two weeks) of exposure would lead to breakthrough ovulation-mediated changes in endogenous estradiol (E2) and progesterone (P4) concentrations among etonogestrel (ENG) implant users. <h3>Methods</h3> We enrolled healthy people using ENG implants for 12–36 months. We measured baseline serum concentrations of E2 and P4 as surrogate biomarkers for ovulation suppression using clinical chemiluminescent immunoassays. After two weeks of rifampin 600 mg daily, we repeated E2 and P4 measurements. We determined breakthrough ovulation based on pre-exposure P4 3.0ng/mL with concurrent rise in post-treatment E2. <h3>Results</h3> Fifteen participants completed all study procedures. Participants' median age was 28.2 (range, 21.8–34.1), median BMI was 25.2 kg/m2 (range, 18.9–37.3), and median duration of implant use was 22 months (range, 12–32). At baseline, median E2 concentrations were 73 pg/mL (range, 32–686) and median P4 concentrations were 0.3 ng/mL (range, 0.2–6.1). After concomitant rifampin, median E2 concentrations were 201 pg/mL (range, 59–951) and median P4 concentrations were 0.4 ng/mL (range, 0.2–15.8). Serum E2 concentrations significantly increased with rifampin exposure (p=0.003, paired Wilcoxon signed rank test), but the increases in serum P4 concentrations were not statistically significant (p=0.185). Three participants (20%) experienced breakthrough ovulation with the following P4 changes: 0.3>5.0, 0.8>7.3, 0.5>15.8 (pre>post; ng/mL). <h3>Conclusions</h3> With only a short exposure to a strong CYP3A inducer, ENG implant users experienced clinically significant changes in hormone biomarkers indicative of waning follicular development and ovulation suppression.

PROGESTOGEN HYPERSENSITIVITY – A CASE SERIES

<h3>Introduction</h3> Progestogen hypersensitivity (PH) is characterized by recurring heterogenous symptoms after endogenous progesterone or exogenous progestogen exposure. The pathogenesis of PH is poorly understood, and the diagnostic and therapeutic approach are not well established. Here we sought to characterize a PH cohort at our institution. <h3>Methods</h3> A retrospective chart review of adult women with symptoms suggestive of PH was conducted across the 3 Mayo Clinic sites. Data regarding the symptomatology, diagnostic approach, treatment decision, and outcome were collected and analyzed. <h3>Results</h3> Forty-two patients had a clinical presentation consistent with PH. Mean age of onset was 30.5 years. 24% of patients had an exogenous progestogen trigger. Of the exogeneous triggers, 50% were oral contraceptives, 20% progesterone intrauterine devices, 20% progesterone supplementation for <i>in vitro</i> fertilization or risk reduction of premature birth, and 10% vaginal rings. 57% (n=24) had a medical history of atopy. The most common clinical manifestation was dermatologic (93%). Symptoms included dermatitis (48%), urticaria (48%), angioedema (50%), mouth sores (7%), vesiculobullous eruptions (14%). Three patients presented with anaphylactic reaction. Progesterone skin testing was performed in 29/42 (69%) patients, with 9/29 (31%) being positive. Non-hormonal treatment strategies included oral steroids (43%), topical steroids (31%), and monoclonal antibodies (12%). Hormone-based therapies included oral contraceptives (26%), GnRH antagonist (26%), and oophorectomy (10%). A desensitization protocol was performed in 12% of patients. 48% of patients improved with treatment. <h3>Conclusion</h3> Here we report a large case series of PH patients. Further studies addressing the diagnostic challenges and treatment outcomes are warranted.

RF24 | PSUN110 A Cross-Sectional Study Evaluating the Impact of Combined Hormonal Contraceptives on Components of Energy Balance in Pre-Menopausal Women with Overweight or Obesity

Abstract Background Combined estrogen and progestin hormonal contraceptives (CHCs, including combined oral contraceptives, hormonal patches, or vaginal rings) expose women to supraphysiologic levels of reproductive hormones, which in turn suppress endogenous estrogen and progesterone. Sustained elevations of synthetic estrogen/progestin or suppression of endogenous hormones in CHC users may lead to altered dietary intake and/or patterns of physical activity (PA). Previously, we reported that CHC use was associated with higher energy intake (EI) and weight regain over 1 year after weight loss in women with overweight and obesity enrolled in a behavioral weight loss program, suggesting a potential impact of CHCs on energy balance in the weight reduced state. The aim of this secondary data analysis was to compare dietary intake and PA in weight-stable women with overweight or obesity using CHCs to non-CHC users. Methods Pre-menopausal women with overweight or obesity (n=269, age 18-55 years, BMI 27-45kg/m2) enrolled in 3 different interventional weight loss trials were categorized as CHC users (CHC, n=48) or non-CHC controls (CON, n=221). Fat mass (FM) and lean mass (LM) were measured with DXA. Self-reported dietary energy and macronutrient intake was obtained from either 3-day (n=178) or 7-day (n=91) written diet diaries and analyzed using Nutrition Data System for Research (NDSR) software. Healthy eating index (HEI) scores for diet quality were calculated in a subset (CHC=17, CON=84) of participants using variables available in NDSR output files. Additionally, average daily step counts were measured over 1 week in a subset (CHC=27, CON=143) of participants using the activPAL device. Results Age was lower in CHC users (mean±SD; CHC 35.3±9.0 vs. CON 39.4±7.6 years, p&amp;lt;0.01), but race and ethnicity did not differ between the two groups. After controlling for age, there were no significant differences between groups in baseline BMI (mean±SEM; CHC 34.3±0.7 vs. CON 34.8±0.3 kg/m2), weight (93.6±2.4 vs. 94.2±1.1 kg), %FM (43.3±0.6 vs. 42.7±0.3%), or %LM (54.3±0.6 vs. 54.7±0.3%). There were no significant differences between groups in EI (mean±SEM; CHC 1763.7±78.1 vs. CON 1768.8±36.7 kcal); proportions of fat (36.7±0.9 vs. 36.9±0.4%), carbohydrate (43.9±1.1 vs. 44.3±0.5%), and protein intake (17.7±0.6 vs. 17.3±0.3%); or HEI scores (58.3±2.9 vs. 56.8±1.3). There was a trend for lower daily step count in CHC users (mean±SEM; CHC 5978±460 vs. CON 6913±197 steps/day, p=0.07). Conclusion Daily steps tended to be lower in CHC users compared to controls, while differences in self-reported dietary intake were not observed. Future studies that are done in larger samples over a greater range of BMI and with more detailed measures of PA timed to the menstrual cycle are needed to explore the extent to which CHC use may impact energy balance in women. Presentation: Sunday, June 12, 2022 12:30 p.m. - 2:30 p.m., Sunday, June 12, 2022 1:06 p.m. - 1:11 p.m.

Dexamethasone application for in vitro fertilisation in non-classic 17-hydroxylase/17,20-lyase-deficient women.

High progesterone levels in the follicular stage interfere with the implantation window, causing infertility in women with 17-hydroxylase/17,20-lyase deficiency (17OHD). Dexamethasone can restore cortisol deficiency and suppress inappropriate mineralocorticoid secretion to control hypertension in 17OHD patients, but poses risks to the foetus if administered during pregnancy. We prospectively explored a rational glucocorticoid use protocol for assistive reproduction in a woman with non-classic 17OHD that reduced glucocorticoid side effects. In this study, the treatment protocol for this 17OHD patient included the following steps. First, the appropriate type and dose of glucocorticoid for endogenous progesterone suppression was determined. Then, glucocorticoid was discontinued to increase endogenous progesterone levels for ovarian stimulation. Next, dexamethasone plus GnRHa were used to reduce progesterone levels in frozen embryos for transfer. Once pregnancy was confirmed, dexamethasone was discontinued until delivery. Dexamethasone, but not hydrocortisone, reduced progesterone levels in the 17OHD woman. After endogenous progesterone-primed ovarian stimulation, 11 oocytes were retrieved. Seven oocytes were 2PN fertilised and four day-3 and two day-5 embryos were cryopreserved. After administering dexamethasone plus gonadotropin-releasing hormone agonist (GnRHa) to reduce progesterone levels to normal, hormone replacement therapy was administered until the endometrial width reached 9mm. Exogenous progesterone (60 mg/day) was used for endometrial preparation. Two thawed embryos were transferred on day 4. Dexamethasone was continued until pregnancy confirmation on the 13th day post-transfer. Two healthy boys, weighing 2100 and 2000g, were delivered at 36 weeks' gestation. Rational use of dexamethasone synchronised embryonic development with the endometrial implantation window, while not using in post-implantation avoided its side effects and promoted healthy live births in women non-classic 17OHD undergoing in vitro fertilisation.

Utilizing an Endogenous Progesterone Receptor Reporter Gene for Drug Screening and Mechanistic Study in Endometrial Cancer.

Simple SummaryIn this study, we generate an innovative endogenous progesterone receptor (PR) reporter gene containing endometrial cancer cell lines and use this tool to visualize PR expression in real-time. We also demonstrated two strategies of using this reporter gene: (1). Drug discovery—screening small molecule inducers for PR expression; (2). Mechanistic investigation—screening potential PR repressors using genome-wide CRISPR knockout library.Expression of progesterone receptor (PR) is a favorable prognostic marker for multiple solid tumors. However, PR expression is reduced or lost in malignant tumors. Thus, monitoring and restoring functional PR expression is important in order to sensitize tumor cells to progesterone therapy in endometrial cancer. We developed stable PR reporter gene containing endometrial cancer cell lines monitoring the endogenous PR expression by inserting mCherry and hygromycin resistant gene at the endogenous PR gene locus by CRISPR/Cas9-mediated genome editing technique. This allows efficient, real-time monitoring of PR expression in its native epigenetic landscape. Reporter gene expression faithfully reflects and amplifies PR expression following treatment with drugs known to induce PR expression. Small molecular PR inducers have been identified from the FDA-approved 1018 drug library and tested for their ability to restore PR expression. Additionally, several candidate PR repressors have been identified by screening the genome-wide CRISPR knockout (GeCKO) library. This novel endogenous PR reporter gene system facilitates the discovery of a new treatment strategy to enhance PR expression and further sensitize progestin therapy in endometrial cancer. These tools provide a systematic, unbiased approach for monitoring target gene expression, allowing for novel drug discovery and mechanistic exploration.

291 Synchronization and Seasonality Effects on Follicular Development, Estrus Expression, and Pregnancy in Brahman Females

Abstract Control of follicular development is essential for estrous synchronization. This experiment determined differences in follicular development during synchronization in Brahman females. Cows (n=219) and heifers (n=90) in Fall (n=170) and Spring (n=139) were synchronized with a CIDR insert and administration of GnRH or PG treatment on d0 (1/2GnRH: n=106, GnRH: n=103, PG: n=100), and CIDR removal and PG administration on d6 followed by estrus detection and AI for 96h. Blood samples were collected on d0, d6, and d8 and/or AI to determine circulating progesterone (P4) concentrations. Transrectal ovarian ultrasonography occurred daily. Cows were grouped by CL presence (d0CL, d6CL) and P4 concentrations (d0P4, d6P4, d8P4, Low&amp;lt; 1 ng/mL, High≥1 ng/mL) on d0 and d6. The GLIMMIX procedure of SAS was used to analyze follicular wave initiation, wave emergence day, estrus expression, and pregnancy success. There were significant interactions of treatment by d0CL (P=0.0237), and season by d0P4 (P=0.0118) on wave initiation. Cows receiving 1/2GnRH with a CL on d0 (97±2%) and Fall cows having High d0P4 (96±3%) had the greatest probability of wave initiation. Age significantly impacted wave initiation (P=0.0213; heifers: 93±4%, cows: 79±5%). Interactions of treatment by season (P=0.0405) and treatment by d0CL (P=0.0379) significantly impacted wave emergence timing. Season (P&amp;lt; 0.0001; Fall: 23±5%, Spring: 65±6%), and the interactions of treatment by d0P4 (P=0.0291) and new wave by d0P4 (P=0.0357) influenced estrus expression. Cows receiving 1/2GnRH with High d0P4 and cows with High d0P4 that initiated a new wave had the greatest probability of estrus expression. Pregnancy rate differed by estrus expression (P=0.0055; no estrus=25±6%, estrus=54±8%) and semen type (P=0.0105; conventional=52±9%, sexed=26±6%), and tended to differ by d8P4 (P=0.0570; Low=30±7%, High=48±8%). These results suggest that differences in follicular development and behavioral estrus in synchronized Brahman females may be due to seasonality and endogenous progesterone production.

The Correlation of Endogenous Progesterone Concentration in Diestrus on Early Pregnancy Rate in Thoroughbred Mares

The aim of this project was to test the hypothesis that progesterone concentration 5 days after ovulation did not differ between pregnant and nonpregnant Thoroughbred mares on stud farms located in the Waikato region of New Zealand. A prospective cohort study was performed involving five stud farms in the Waikato region of New Zealand during the 2018 breeding season. A total of 275 mares were enrolled in the study. Mares were served by 34 individual stallions. Blood samples were taken from each mare 5 days after ovulation (D0) and measured for progesterone concentration. Early pregnancy was confirmed at D14 by transrectal palpation and ultrasonography of the mares reproductive tract. Progesterone concentration at Day 5 post-ovulation was higher in mares determined to pregnant at Day 14 of gestation than in mares determined to be non-pregnant at Day 14 (6.4 ± 3.0 ng/ml vs. 5.5 ± 3.3 ng/ml respectively; P = .02). A negative association between increasing mare age and pregnancy rate was found but mare age had no effect on progesterone concentration at D5. In this study we found that although higher serum progesterone concentration at Day 5 post ovulation was associated with a higher pregnancy rate at Day 14, no predictive or definitive minimum required progesterone concentration could be identified. Additional studies are required to determine if a synthetic progestogens can serve to supplant natural progesterone to increase pregnancy rate in naturally bred mares.

Shifts in uterine bacterial communities associated with endogenous progesterone and 17β-estradiol concentrations in beef cattle

The relation between circulating concentrations of progesterone and 17β-estradiol prior to insemination play a key role in optimizing fertility in cattle. This study aimed to determine the impact of endogenous progesterone (P4) and estradiol (E2) concentrations on uterine bacterial community abundance and diversity in beef cattle. Angus-influenced heifers were subjected to an industry standard estrous synchronization protocol. Uterine flushes were collected on d -2 (endogenous P4) and d 0 (endogenous E2) and used for targeting the V4 hypervariable region of 16S rRNA bacterial gene. Plasma was collected on d -2 and 0 for quantification of P4 and E2 concentrations by radioimmunoassay, respectively. Heifers were allotted to one of the following groups: High P4 + High E2 (H-H; n = 11), High P4 + Low E2 (H-L; n = 9), Low P4 + High E2 (L-H; n = 9), Low P4 + Low E2 (L-L; n = 11). Results indicated that Shannon's diversity index tended to be greater for H-L heifers compared to L-H heifers on d 0 (P = 0.10). For H-L heifers from d -2 to d 0, the relative abundance of Actinobacteria decreased and Tenericutes increased (P < 0.01). Within phylum Actinobacteria, the relative abundance of Corynebacterium decreased from d -2 to d 0 in treatment groups H-H, H-L, and L-L (P < 0.05); however, did not differ by d for L-H heifers. Within phylum Tenericutes, the relative abundance of Ureaplasma increased from d -2 to d 0 for H-L heifers (P = 0.01). Additionally for H-L heifers, the relative abundance of Bacteroidetes tended to increase from day -2 to on d 0 (P = 0.07). For H-L heifers, uterine pH increased from day -2 to d 0 (P = 0.05). These results suggest that differing endogenous concentrations of P4 and E2 may be associated with shifts in uterine microbiota and pH, and this could ultimately impact fertility outcomes in beef cattle.

In vitro investigation of endocrine disrupting effects of pesticides on Ca2+-signaling in human sperm cells through actions on the sperm-specific and steroid-activated CatSper Ca2+-channel.

Ca2+-signaling controls sperm cell functions necessary for successful fertilization. Multiple endocrine disrupting chemicals have been found to interfere with normal Ca2+-signaling in human sperm cells through an activation of the sperm-specific CatSper Ca2+-channel, which is vital for normal male fertility. We investigated 53 pesticides for their ability to interfere with CatSper mediated Ca2+-signaling and function in human sperm cells. Effects of the pesticides on Ca2+-signaling in human sperm cells were evaluated using a Ca2+-fluorometric assay. Effects via CatSper were assessed using the specific CatSper inhibitor RU1968. Effects on human sperm function and viability were assessed using an image cytometry-based acrosome reaction assay and the modified Kremer's sperm-mucus penetration assay. 28 of 53 pesticides were found to induce Ca2+-signals in human sperm cells at 10 µM. The majority of these 28 active pesticides induced Ca2+-signals through CatSper and interfered with subsequent Ca2+-signals induced by the two endogenous CatSper ligands progesterone and prostaglandin E1. Multiple active pesticides were found to affect Ca2+-mediated sperm functions and viability at 10 µM. Low nM dose mixtures of the active pesticides alone or in combination with other environmental chemicals were found to significantly induce Ca2+-signals and inhibit Ca2+-signals induced subsequently by progesterone and prostaglandin E1. Our results show that pesticides, both alone and in low nM dose mixtures, interfere with normal Ca2+-signaling in human sperm cells in vitro in low nM concentrations. Biomonitoring of the active pesticides in relevant matrices such as blood and reproductive fluids is very limited and the effects of real time human pesticide exposure on human sperm cells and fertility thus remains largely unknown. To which extent human pesticide exposure affects the chances of a successful fertilization in humans in vivo needs further research.

Determination of the concentration of selective progesterone receptor modulators in blood plasma BY LC–MS/MS

High-performance liquid chromatography mass spectrometry is a hybrid method and combines independent processes of liquid chromatographic separation and mass spectrometric analysis, which makes it possible to effectively determine the concentration of various substances in complex substances. The optimal parameters for the determination of progesterone, 17-hydroxyprogesterone capronate (17-OHPC) and aglepriston in the blood plasma of cattle by this method have been established in the work. The quantitative determination of the components was carried out by the method of an external standard using reference substances and preliminary construction of calibration dependencies (absolute calibration). To account for the effect on the result of the analysis of various components of blood plasma, the matrix calibration method was used using "pure" plasma, i.e., it did not contain detectable compounds. It was experimentally determined that the time of progesterone peak release is within 2.72 minutes, and the optimal precursor ion is m/z =315.3. In the course of the work carried out, it was found that in the blood plasma of animals, endogenous progesterone is well detected by the developed method according to the parameters set for the synthetic analogue. The peak time of 17-OHPC occurred after 4.20 minutes, and the optimal precursor ion had a mass of 429.2 au. The first stage of studying the kinetics of 17-HPC in cattle showed that the steroid is well visualized on the chromatogram even in low concentrations. The outputs of the peaks of aglepriston were observed at 2.25 minutes, and the optimal precursor ion was equal to 432.2 au.m. The chromatogram even at low concentrations of the steroid had a low noise level, and the concentration of the steroid in the blood plasma a day after injection of 20 ml of 3% aglepriston solution to a lactating cow was 7.2 ng/ml. Thus, optimal parameters were selected for determining the concentration of selective progesterone receptor modulators in the blood plasma of cattle, which allows for further evaluation of the pharmacokinetic properties of these steroids after their use.

Chemical contraceptive impacts on cyclic progesterone and sexual behavior in zoo-housed Western lowland gorillas.

For regularly cycling primates in captivity, chemical contraceptives can be used to reduce the likelihood of unintentional offspring, but the effects on cyclic progesterone and sexual behavior have not been well studied in gorillas (Gorilla gorilla gorilla). As zoos are invested in maintaining naturalistic behaviors and physiology, this is an important aspect of gorilla physical and mental health. We examined how exposure to combination and progestin-only oral birth control pills altered cyclic progesterone and timing of sexual behaviors in four female gorillas at four institutions compared to cycling controls. Hormonal data were collected using fecal steroid metabolites as detected by enzyme immunoassay. Behavioral data were collected via one-zero sampling done by keeper staff. All methods of oral contraceptive eliminated the ovarian cycle, with fecal progestogens being maintained below baselines in cycling control individuals. There was also no evidence of any cyclic patterning in endogenous progesterone, suggesting that the methods tested do not allow for detection of a recovery of endogenous progesterone during a short no-pill period. We also found that the oral contraceptives altered the timing of behavioral displays when compared to cycling control individuals but was not directly related to any fluctuations in endogenous progesterone. This study reveals a need for additional research on contraceptive use in gorillas and reinforces that sexual behavior in gorillas is both hormonally and socially mediated.

P-675 Determining endogenous progesterone levels on the day of HCG triggering in modified natural cycles before frozen-thawed blastocyst transfer. Results and influence on clinical pregnancy rates

Abstract Study question Is the endogenous progesterone level (EPL) on the day of hCG administration associated with pregnancy outcomes in modified natural cycles before embryo transfer? Summary answer The present analysis suggested the negative effect of EPL on clinical pregnancy when progesterone was above 1,1 ng/ml on the day of HCG triggering. What is known already Endogenous progesterone levels (EPL) experience an abrupt increase following the ovulatory LH surge. It is described that this change in basal EPL contributes to modulating the endometrial receptivity in preparation for embryo implantation. Several authors reported a negative impact on the pregnancy of high serum EPL on the day of HCG. These studies revealed accelerated endometrial changes and a subsequent decoupling of the implantation window. These observations involved only patients who underwent ovarian stimulation before the embryo transfer. However, studies based on EPL in modified natural cycles before blastocyst transfer are very limited. Study design, size, duration The present non-interventional pilot cohort study aimed to determine the EPL in patients undergoing an endometrium preparation for frozen-thawed embryo transfer in non-stimulated cycles, and its association with clinical pregnancy rates. A total of 46 participants were included in this analysis. To reduce variability, the mean EPL was calculated excluding 2 outlier values in our dataset. The cut-off value of EPL was established using the Youden-index, and the T-student was used for further statistical comparisons. Participants/materials, setting, methods Patients following our IVF program, who underwent frozen-thawed embryo transfer during the period of study. Our data includes cycles with own and with donated oocytes. The total oocyte average age was 33,5±6,7. All transfers were performed at blastocyst stage. Main results and the role of chance The overall clinical pregnancy rate per embryo transfer was 70,5% (31/44), with an implantation rate of 66,7% (32/48). The mean number of transferred embryos was 1,09, with a single embryo transfer rate of 90,9%. The total mean of EPL was 0,31±0,26 [IC95% 0,23-0,39], with patients who achieved a clinical pregnancy (0,30±0,21; n = 31) showing significantly lower EPL (p-value=0,04) than the non-pregnant participants (0,41±0,40; n = 10). Three out of 44 patients had a biochemical pregnancy, with a mean EPL of 0,12±0,01. EPL cut-off value was establish at 1,1 ng/ml. The evaluation of the total dataset (n = 46 patients, including 2 outliers) showed that 8,7 % of a total of these cases had an EPL above the threshold of 1,1 ng/ml. The clinical pregnancy rate in this subgroup of patients was 25,0%. Limitations, reasons for caution This study includes a limited number of cases. Further analysis is required to confirm the present results and to allow data stratification for additional inter-group comparisons. Wider implications of the findings Evaluating EPL may contribute to improving the clinical outcome in natural modified cycles. We observed that EPL is expected to be lower in non-stimulated than in stimulated cycles, compared to previously published studies. These observations highlight the importance to manage treatment-related EPL thresholds, in particular, to establish transfer decision-making policies. Trial registration number n/a

Inducción de la lactancia en ganado Holstein con dosis reducidas de benzoato de estradiol y sin suplementar progesterona exógena

Lactation induction in cattle is an alternative way to increase the life span of cows with reproductive and productive issues that would otherwise be culled. An alternative lactation induction protocol is proposed. This 21-d protocol takes advantage of endogenous progesterone production and uses low doses of estradiol to stimulate udder growth and function. Holstein cows (n= 5) and heifers (n= 4) were injected with 500 mg of somatotropin on days one, eight, fourteen, and twenty-one. Estradiol benzoate (3-10 mg d-1) was applied from day one to fourteen. Cloprostenol (500 µg) was administered to the animals am and pm on d 1, and from d 18 to 21, they were injected dexamethasone (5 mg d-1). The cows and heifers were milked for the first time on d 22. Exogenous progesterone was not supplemented, but lactation protocol began in the diestrus phase of the estrous cycle and GnRH was injected to induce formation of an accessory corpus luteum. Lactation induction was successful in all animals, milk production ranged from 18.3 to 25.5 kg d-1. In conclusion, endogenous progesterone production in combination with reduced doses of estradiol benzoate is sufficient to induce lactation in Holstein cattle.

Does the HCG trigger dose used for IVF impact luteal progesterone concentrations? a randomized controlled trial

Research questionIs there an association between the ovulation trigger dose of human chorionic gonadotrophin (HCG) and endogenous progesterone production during the luteal phase? DesignThis randomized controlled four-arm study, at the Fertility Clinic, Odense University Hospital, Denmark, included women undergoing gonadotrophin-releasing hormone (GnRH) antagonist IVF treatment with ≤11 follicles ≥12 mm. Group 1–3 were triggered with 5000 IU, 6500 IU or 10,000 IU HCG, respectively, receiving 17α-hydroxyprogesterone caproate intramuscularly for luteal-phase support (LPS) to measure endogenous progesterone production. Group 4 received 6500 IU HCG trigger and vaginal progesterone. During the study, the 5000 IU and 10,000 IU HCG groups were switched from urinary to recombinant HCG, as urinary HCG was removed from market. Eight blood samples were drawn during the luteal phase. ResultsNinety-four participants completed the study. There was a significant positive association between the HCG trigger dose and the progesterone at 8 days (P < 0.001), 10 days (P < 0.001) and 14 days (P < 0.001) post-oocyte retrieval. Comparing the groups individually revealed a significant difference in progesterone concentration between low and high trigger doses at 4 days (P = 0.037) and 8 days (P = 0.007) post-oocyte retrieval and between all intervention groups at oocyte retrieval + 6 days: group 1 and 2 (P = 0.011), group 2 and 3 (P = 0.042) and group 1 and 3 (P < 0.001). Higher HCG trigger dose increased the progesterone from the individual follicle. ConclusionsIncreasing HCG trigger doses significantly increased endogenous progesterone concentration during the mid–late luteal phase.