Gonadotropin-releasing Hormone Group Research Articles

Serum Metabolomic Analysis of Synchronous Estrus in Yaks Based on UPLC-Q-TOF MS Technology.

The yak is a unique species of livestock found in the Qinghai-Tibet Plateau and its surrounding areas. Due to factors such as late sexual maturity and a low rate of estrus, its reproductive efficiency is relatively low. The process of estrus synchronization in yaks plays a crucial role in enhancing their reproductive success and ensuring the continuation of their species. In order to clarify the characteristics of the serum metabolites of yak estrus synchronization, the yaks with inactive ovaries were compared with the estrus synchronization yaks. In this study, yaks were divided into the inactive ovaries group (IO), gonarelin-induced yak estrus group (GnRH), and chloprostenol sodium-induced yak estrus group (PGF). After the completion of the estrus synchronization treatment, blood samples were collected from the jugular veins of the non-estrus yaks in the control group and the yaks with obvious estrus characteristics in the GnRH and PGF groups. Metabolites were detected by ultra-high performance liquid chromatography-mass spectrometry, and differential metabolites were screened by multivariate statistical analysis. The results showed that a total of 70 significant differential metabolites were screened and identified in the GnRH vs. IO group, and 77 significant differential metabolites were screened and identified in the PGF vs. IO group. Compared with non-estrus yaks, 36 common significant differential metabolites were screened out after the induction of yak estrus by gonarelin (GnRH) and cloprostenol sodium (PGF), which were significantly enriched in signaling pathways such as the beta oxidation of very long chain fatty acids, bile acid biosynthesis, oxidation of branched chain fatty acids, steroidogenesis, steroid biosynthesis, and arginine and proline metabolism. This study analyzed the effects of gonadotropin releasing hormone (GnRH) and prostaglandin F (PGF) on the reproductive performance of yaks treated with estrus synchronization, which provides a theoretical basis for the optimization and application of yak estrus synchronization technology and promotes the healthy development of the yak industry.

Effect of a Single Injection of GnRH Analog Alone and at the Time of AI on Reproductive Performance of Nili Ravi Buffaloes

Introduction: The gonadotropin-releasing hormone (GnRH) is a decapeptide hormone released from basal neurons of the hypothalamus. It stimulates the production of follicle-stimulating hormone (FSH) and luteinizing hormone (LH) in the pituitary. The objective of the study was to evaluate the effect of a single injection of gonadotropin-releasing hormone (GnRH) analog at the time of artificial insemination (AI) on buffalo estrus, conception, pregnancy, and calving rate. Materials and methods: The anestrus nulliparous Nili Ravi buffalo heifers (n=80) were divided into 4 groups randomly. Group A (n=20) received only a single injection of GnRH analog at start of the experiment (Day 0), group B (n=20) received a single injection of GnRH analog at Day 0 and prostaglandine (PGF2α) at Day 7, group C (n=20) received progesterone sponge for 7 days, and group D (n=20) received progesterone sponge for 7 days and PGF2α at Day 9. In 2nd study, buffaloes (n=60) expressing first (n=20), second (n=20), and third (n=20) postpartum estrus were enrolled. Moreover, heifers (n=20), expressing estrus first time were also included. Animals (n=10) from each group, received a single injection of GnRH analog at the time of AI were named as treatment group and the control (n=10) did not receive any treatment. Pregnancy tests were performed with the help of ultrasound on days 35 and 65 post-AI. Results: The pregnancy and calving rates were lower in GnRH group compared to other treatments. Similarly, the administration of GnRH analog did not increase pregnancy rates in treatment groups. Conclusion: The single injection of GnRH analog alone at the time of AI did not improve the reproductive performance of buffaloes.

Effect of GnRH on the day of Insemination on Ovulatory Response in Crossbred Cows

The effect of gonadotropin releasing hormone (GnRH) analogue on the ovulatory response of oestrual follicle during cold and hotter months of the year was studied. A total of 120 crossbred cows brought for insemination with oestrus signs during colder months (December 2022 –January 2023; n=52) and hotter months (April – May 2023; n=68) to the Gynaecology Unit of Veterinary Clinical Complex, Veterinary College and Research Institute, Orathanadu were utilized for the study. Oestrus (Day 0) was confirmed by gynaeco-clinical and ultrasound examination and animals were inseminated with (n =33) or without (n = 87) GnRH (Buserelin acetate 10 mcg; im). The biometry of oestrual follicle (OF) and regressing corpus luteum (RCL) were measured ultrasonographically on Day 0 and the OF was observed every 24 hours until ovulation. The diameter of the OF on Day 0 was non-significantly (P > 0.05) larger during hotter months (12.19 ± 0.21 mm) than colder months (11.58 ± 0.32 mm). There were no significant (P > 0.05) differences in the diameter of RCL between the two periods (9.63 ± 0.21 and 9.56 ± 0.22 mm respectively). OFs were observed majorly in the right ovary during the hotter (60.76%) and colder (54.17%) months. Ovulations occurred on the mean days of 1.00 and 1.37 ± 0.18 in GnRH group during hotter (H-Gn) and colder months (C-Gn) respectively. The respective mean days in non-GnRH group were 1.14 ± 0.05 and 1.33 ± 0.08 during hotter (H-O) and colder months (C-O). In H-Gn group all the animals (100%) ovulated on Day 1, when compared to C-Gn animals (62.50%). On perusing the possible effect of RCL on ovulation, significantly increased percentages of ovulations were observed in OFs on the contralateral ovary to the ovary having the RCL in GnRH group and viceversa in non-GnRH group. It could be assumed that GnRH administration on the day of insemination may be beneficial during the hotter months of the year.

Pulsatile Gonadotropin-Releasing Hormone Therapy Is Associated With Better Spermatogenic Outcomes than Gonadotropin Therapy in Patients With Pituitary Stalk Interruption Syndrome

ObjectiveTo compare the effects of combined gonadotropin and pulsatile gonadotropin-releasing hormone (GnRH) therapy on spermatogenesis in patients with pituitary stalk interruption syndrome (PSIS). MethodsMale patients with PSIS (N = 119) were retrospectively studied. Patients received pulsatile GnRH therapy (N = 59) were divided into response and poor-response groups based on luteinizing hormone (LH) levels after 1-month treatment with a cutoff value of 1 or 2 IU/L. Participants with gonadotropin therapy were divided into human menopausal gonadotropin (hMG)/human chorionic gonadotropin (hCG) group (N = 60), and patients with pulsatile GnRH therapy were classified into GnRH group (N = 28) with treatment duration ≥6 months. ResultsThe overall success rates of spermatogenesis for hMG/hCG and GnRH therapy were 51.67% (31/60) vs 33.90% (20/59), respectively. GnRH group required a shorter period to induce spermatogenesis (8 vs 15 months, P = .019). hMG/hCG group had higher median total testosterone than GnRH group [2.16, interquartile range(IQR) 1.06-4.89 vs 1.31, IQR 0.21-2.26 ng/mL, P = .004]. GnRH therapy had a beneficial effect on spermatogenesis compared to hMG/hCG therapy (hazard ratio 1.97, 95% confidence interval 1.08-3.57, P = .026). In patients with pulsatile GnRH therapy, compared with the poor-response group, the response group had a higher successful spermatogenesis rate (5.00% vs 48.72%, P = .002) and higher median basal total testosterone (0.00, IQR 0.00-0.03 vs 0.04, IQR 0.00-0.16 ng/mL, P = .026) with LH = 1 IU/L as the cutoff value after 1-month pulsatile GnRH therapy. ConclusionsPulsatile GnRH therapy was superior to hMG/hCG therapy for spermatogenesis in patients with PSIS. Earlier spermatogenesis and higher concentrations of sperm could be obtained in the GnRH group if patients received therapy over 6 months.

Live Birth Outcomes for PCOS Patients Under the Follicular-Phase Long-Acting GnRH Agonist Protocol or Antagonist Protocol - A Retrospective Chinese Cohort.

For patients with polycystic ovary syndrome (PCOS) to undergo in vitro fertilization (IVF) and embryo transfer (ET), there has been no consensus regarding which protocol is the most optimal for live birth rate in fresh cycles. We sought to evaluate depot gonadotropin-releasing hormone (GnRH) agonist protocol versus GnRH antagonist protocol in IVF outcomes for PCOS patients in a single fertility center. In this retrospective cohort, PCOS patients who visited the Second Hospital of Hebei Medical University reproductive center between February 2012 and December 2019 were screened, and 533 PCOS infertility patients were included undergoing their first IVF cycle, with 470 in the depot GnRH agonist group and 63 in the GnRH antagonist group. The primary of this study outcome was the fresh live birth rate (LBR). PCOS women in the depot GnRH agonist group had a higher LBR (49.79%) than those in the GnRH antagonist group (34.92%, p = 0.027). The multivariable logistic regression also confirmed that women in the depot GnRH agonist group had a higher LBR than those in the GnRH antagonist group (OR = 1.83, 95% CI 1.05~3.18, p = 0.032). After propensity score matching (PSM), the LBR in the depot GnRH agonist group was higher (50.32%) than that of the GnRH antagonist group (35.48%), p = 0.033. The ovarian hyperstimulation syndrome (OHSS) rates were similar between the two groups, with 35 in the depot GnRH group and 6 in the GnRH antagonist group (p = 0.561). For PCOS patients in fresh embryo transfer cycles, the depot GnRH agonist protocol may lead to a higher LBR than the antagonist protocol with satisfied lower OHSS rates.

Androgen Deprivation Therapy and Risk of Cardiovascular Disease in Patients With Prostate Cancer Based on Existence of Cardiovascular Risk

Controversy exists regarding the risk of cardiovascular disease (CVD) associated with androgen deprivation therapy (ADT) in patients with prostate cancer. We sought to evaluate the association between gonadotropin-releasing hormone (GnRH) agonists versus GnRH antagonist and the risk of CVD in patients with prostate cancer with or without prior CVD. Using administrative databases from Quebec, Canada, we identified first-time GnRH agonists and antagonist (degarelix) users between January 2012 and June 2016. Follow-up ended at the earliest of the following: first CVD event (myocardial infarction [MI], stroke, ischemic heart disease [IHD], arrhythmia, and heart failure [HF]); switch of GnRH group; death; or December 31, 2016. Inverse probability of treatment weighting (IPTW) based on the propensity score was used to control for potential confounding. IPTW-Cox proportional hazards model accounting for competing risks was used to evaluate the association of interest. Among 10,785 patients identified, 10,201 and 584 were on GnRH agonists and antagonist, respectively. Median age was 75 years (interquartile range, 69-81 years) for both groups. A total of 4,152 (40.7%) men in the GnRH agonists group and 281 (48.1%) men in the GnRH antagonist group had CVD in the 3-year period prior to ADT initiation. Risk of HF was decreased in the antagonist group compared with the GnRH agonist group among patients with prior CVD (hazard ratio [HR], 0.46; 95% CI, 0.26-0.79). Risk of IHD was decreased in the antagonist group in patients without prior CVD (HR, 0.26; 95% CI, 0.11-0.65). Use of antagonist was associated with an increased risk of arrhythmia among patients with no prior CVD (HR, 2.34; 95% CI, 1.63-3.36). Compared with GnRH agonists, the GnRH antagonist was found to be associated with a decreased risk of HF, specifically among patients with prior CVD. Among those with no prior CVD, the GnRH antagonist was associated with a decreased risk of IHD but an increased risk of arrhythmia.

The efficacy of gonadotropin-releasing hormone agonist treatment before hysteroscopic myomectomy for large-sized submucosal leiomyoma.

To evaluate the efficacy and safety of a gonadotropin-releasing hormone (GnRH) agonist for treating large-sized submucosal leiomyoma before hysteroscopic myomectomy.The data were retrospectively collected from patients who underwent a hysteroscopic myomectomy for a submucosal leiomyoma >3.5 cm in size from January 2009 to December 2018. The patients were divided into the GnRH group and the control group according to whether they were pretreated before surgery.A total of 61 patients were included in the study, 31 in the GnRH agonist group and 30 in the control group. At diagnosis, the maximum leiomyoma diameter was similar between the 2 groups (4.67 ± 0.6 cm in the GnRH agonist group vs 3.82 ± 0.6 cm in the control group, P = .061). After pretreatment with the GnRH agonist, the maximum diameter was significantly smaller in the GnRH agonist group compared to the control group (3.82 ± 0.6 vs 4.33 ± 0.8 cm, respectively, P = .004). The leiomyoma volume in the GnRH agonist group decreased by 55.6%, from 41.68 ± 15.7 to 23.19 ± 10.4 cm3, which led to significant differences in leiomyoma volume between the 2 groups (23.19 ± 10.4 cm3 in the GnRH agonist group vs 33.22 ± 24.7 cm3 in the control group, P = .042). The GnRH agonist group showed a shorter operation time (37.7 vs 43.9 minutes, P = .040) and less uterine distention media was used (6800 vs 9373.3 mL, P = .037) compared to the control group. Postoperative complications such as estimated blood loss, remnant leiomyoma, and recurrence were similar between the 2 groups.Treatment with a GnRH agonist before hysteroscopic myomectomy for large submucosal leiomyoma might decrease the volume of the leiomyoma, reduce operation time, and the amount of uterine-distension media used without surgical complications.

Ovarian luteal category at the time of exogenous progesterone treatment alters pre-ovulatory follicle size and pregnancy outcome but not initial GnRH treatment in repeat-breeder crossbred dairy heifers submitted to the 7-day fixed-time AI protocol

Repeat breeding is a substantial problem in heifer and cow breeding leading to greater infertility for female dairy herds. The aim of present study was to investigate the impact of corpus luteum (CL) presence and category and the first gonadotropin-releasing hormone (GnRH) administration concurrent with exogenous progesterone (P4) treatment on the largest follicle (LF) size and pregnancy rate (PR) in repeat-breeder crossbred dairy heifers submitted to the fixed-time artificial insemination (AI) protocol. Heifers (n= 243) were synchronised with (+GnRH) or without (–GnRH) first GnRH in the 7-day P4-GnRH-prostaglandin F2α-based programme. Each GnRH group was divided on presence of CL into two groups (+CL and –CL) in a 2 × 2 factorial arrangement. The PR was similar among –GnRH–CL (20.7%), –GnRH+CL (68.8%), +GnRH–CL (30.4%), and +GnRH+CL (68.3%) groups. However, presence of CL in heifers produced a 43.6% increase in PR compared to PR of heifers without CL (odds ratio = 6.550). Heifers bearing large-sized CL had greater large-sized LF on the day of fixed-time AI and PR. Plasma P4 concentration was positively related with CL diameter (r= 0.845; p < 0.001). The diameter of ovarian LF on the day of fixed-time AI was positively associated with P4 concentrations (r= 0.512; p < 0.001). We highlight that ovarian CL presence and category at the time of exogenous P4 treatment alters pre-ovulatory follicle size and PR but not initial GnRH treatment in repeat-breeder crossbred dairy heifers submitted to service with the 7-day fixed-time AI programme.

Comparison of the effect of Gonadotropin-Releasing Hormone and Human Chorionic Go3nadotropin on Reproductive Performance of Romanov Ewes During the Natural Breeding Season.

Low pregnancy rate is an important issue in small ruminants. Superovulation protocols would serve as the possible techniques to increase the pregnancy rate in small ruminants due to the use of synthetic hormones. The present study aimed to assess the effect of gonadotropin-releasing hormone (GnRH) and Human chorionic gonadotropin (hCG) after artificial insemination (AI) on the pregnancy rate of Romanov ewes breed. To this end, estrus was synchronized in 140 ewes using a controlled internal drug-releasing (CIDR) device. Following CIDR removal, all ewes received 400 IU Pregnant Mare's Serum Gonadotropin (PMSG). The ewes were assigned to three groups (control, n=20; experimental groups, each of them was divided into three subgroups, n=20). The first group in each experiment was assumed as control. The second and third groups received three levels of GnRH, (400, 500, and 600 µg, n=20) and hCG (200, 300, and 400 IU) administered by the intramuscular (IM) route. As soon as the signs of estrus were observed, the ewes were isolated from the others and artificially inseminated with fresh sperm using the transcervical method. The results indicated that there were no significant differences between experimental groups in ovulation and pregnancy rates on days 33 and 90 post-AI (P>0.05). The highest twin birth rate (20%) was recorded in the hCG group (300 IU), as compared to GnRH and control groups (P<0.05). The effect of GnRH and hCG on the plasma concentration of progesterone was significant (P<0.01). The groups significantly differed in fecundity rate (Single birth, twin birth, and triple birth) (P<0.05), all of these parameters were significantly higher in the hCG 300 IU group. It can be concluded that the injection of 300 IU of hCG hormone after insemination improves pregnancy rate in ewes.

Efficacy and safety of human chorionic gonadotropin combined with human menopausal gonadotropin and a gonadotropin-releasing hormone pump for male adolescents with congenital hypogonadotropic hypogonadism.

Background:Compared to adult studies, studies which involve the treatment of pediatric congenital hypogonadotropic hypogonadism (CHH) are limited and no universal treatment regimen is available. The aim of this study was to evaluate the feasibility of human chorionic gonadotropin (hCG)/human menopausal gonadotropin (hMG) therapy for treating male adolescents with CHH.Methods:Male adolescent CHH patients were treated with hCG/hMG (n = 20) or a gonadotropin-releasing hormone (GnRH) pump (n = 21). The treatment was divided into a study phase (0–3 months) and a follow-up phase (3–12 months). The testicular volume (TV), penile length (PL), penis diameter (PD), and sex hormone levels were compared between the two groups. The TV and other indicators between the groups were analyzed using a t-test (equal variance) or a rank sum test (unequal variance).Results:Before treatment, there was no statistical difference between the two groups in terms of the biochemistry, hormones, and other demographic indicators. After 3 months of treatment, the TV of the hCG/hMG and GnRH groups increased to 5.1 ± 2.3 mL and 4.1 ± 1.8 mL, respectively; however, the difference was not statistically significant (P > 0.05, t = 1.394). The PL reached 6.9 ± 1.8 cm and 5.1 ± 1.6 cm (P < 0.05, t = 3.083), the PD reached 2.4 ± 0.5 cm and 2.0 ± 0.6 cm (P < 0.05, t = 2.224), respectively, in the two groups. At the end of 6 months of treatment, biomarkers were in normal range in the two groups. Compared with the GnRH group, the testosterone (T) level and growth of PL and PD were significantly greater in the hCG/hMG group (all P < 0.05). While the TV of both groups increased, the difference was not statistically significant (P > 0.05, t = 0.314). After 9 to 12 months of treatment, the T level was higher in the hCG/hMG group. Other parameters did not exhibit a statistical difference.Conclusions:The hCG/hMG regimen is feasible and effective for treating male adolescents with CHH. The initial 3 months of treatment may be a window to optimally observe the strongest effects of therapy. Furthermore, results from the extended time-period showed positive outcomes at the 1-year mark; however, the long-term effectiveness, strengths, and weaknesses of the hCG/hMG regimen require further research.Trial Registration:ClinicalTrials.gov, NCT02880280; https://clinicaltrials.gov/ct2/show/NCT02880280.

Use of GnRH for Synchronization of the Follicular Wave in Assisted Reproductive Technologies in Sheep: A Preliminary Study.

Simple SummaryThe present study aimed to set up a short-term protocol for synchronization of follicular wave emergence in sheep, concomitant with estrus synchronization, which would improve ovarian response in assisted reproductive technologies. Administration of a single dose of gonadotrophin-releasing hormone (GnRH), concomitant with the insertion of a progesterone-loaded controlled internal drug release (CIDR) device, caused regression of gonadotrophin-dependent follicles in all test sheep, with 70% of them initiating a new follicular wave and the remaining showing non-dominant follicles.The present study aimed to set up a short-term protocol for synchronization of follicular wave emergence in sheep, concomitant with estrus synchronization, which would improve ovarian response in assisted reproductive technologies. Administration of a single GnRH dose, concomitant with the insertion of a progesterone-loaded CIDR device, caused regression of gonadotrophin-dependent follicles ≥4 mm in all the GnRH-treated sheep and in around 80% of the controls treated only with CIDR (p < 0.05). Similar percentages of ewes lost all follicles (around 70%) or only the largest one (around 30%) in both groups. Hence, 54.1% and 70% of the sheep lost all large follicles and initiated a new follicular wave in the control and GnRH groups, respectively (p < 0.05). The remaining sheep showed follicles that were still not dependent of luteinizing hormone (LH). So, in fact, all the sheep had non-dominant follicles after treatment. In conclusion, a treatment including GnRH at CIDR insertion would offer a time- and cost-efficient protocol for inducing follicular turnover and synchronizing a new follicular wave at any stage of the estrous cycle.

Comparison of letrozole with gonadotropin-releasing hormone agonist in frozen embryo transfer after recurrent implantation failure: An RCT.

BackgroundThe use of frozen embryo transfer (FET) is increasing worldwide in the treatment of infertility by in vitro fertilization. Different methods of endometrial preparation for FET have been suggested.ObjectiveThe aim of this study was to compare the pregnancy outcomes after treatment with letrozole and those after treatment with the combination of gonadotropin-releasing hormone (GnRH) agonist and estradiol in FET.Materials and MethodsThis randomized controlled trial study was conducted on 142 infertile women with a history of previous FET failure. Participants were randomly assigned to two groups (n = 71 each). The GnRH group received 500 µg of buserelin plus 4mg estradiol (which increased to 8 mg if endometrial thickness was less than 5 mm), and the letrozole group received 5 mg of letrozole plus 75 IU of recombinant human follicle-stimulating hormone). At least two high-quality embryos were transferred to each subject in both groups. The outcome measures were clinical pregnancy rate and fetal heart rate detection.ResultsSubjects in the study groups had similar demographic characteristics and baseline clinical condition. Mean endometrial thickness in the letrozole and GnRH agonist groups were 8.90 0.88 mm and 8.99 0.85 mm, respectively (p = 0.57). The number of positive results of the beta human chorionic gonadotropin test and detection of fetal heartbeat were not significantly different between the groups (p 0.05).ConclusionThe administration of letrozole and GnRH may produce similar pregnancy outcomes in FET.

Experience of treatment precocious puberty by gonadotropin-releasing hormone agonists of prolonged action

Central precocious puberty (CPP) occupies an important place in the practice of pediatric endocrinologist. In the treatment of all forms of CPP, there are used drugs of GnRH (gonadotropin-releasing hormone) agonists group, whose pharmacological effect of is based on desensitization of the pituitary gland to the stimulating effect of GnRH. Therapy with agonist of gonadotropin-releasing hormone allows to stop the progression of sexual development, reduce the rate of bone maturation and, thereby, increase the final growth of the child. The article demonstrates the structure of the dispensary group of patients with CPP who were treated with the agonists GnRH of prolonged action. There has been conducted the analysis of the observation results of patients with idiopathic CPP who received 3.75 mg Triptorelin therapy in the standard regimen once every 28 days and transferred to Tryptorelin 11.25 mg once every 3 months, as well as patients with different forms of CPP with a newly established diagnosis. The presented results of treatment with 11.25 mg Triptorelin drugs by intramuscular injection in a regimen of 1 time in 3 months in comparison with the results of treatment with 3.75 mg of Triptorelin patients in the regimen of intramuscular injections once every 28 days in patients with CPP showed their effectiveness. Preparations of the agonists GnRH group of prolonged action inhibit the development of secondary sexual characteristics, lead to a decrease in the size of the internal genitalia in female and external genitalia in male and reduce the progression of bone age. It was also noted that reducing the frequency of injections of drugs of this group from 1 time in 28 days to 1 time in 3 months positively affects the emotional state of children receiving this treatment for a long period (3-6 years).

105 Optimization of a five-day fixed-time embryo transfer program in dairy heifers: Use of gonadotrophin-releasing hormone at initiation of the protocol

Optimized fixed-time embryo transfer (FTET) protocols for synchronization of recipients have the potential to improve the overall efficiency and profitability of embryo transfer (ET) programs. The objective of the present study was to evaluate the effect of dose of gonadotrophin-releasing hormone (GnRH) at initiation of a 5-day synchronization protocol for FTET. Holstein heifers (n=2689) at two locations were synchronized using a 5-day CO-Synch protocol as follows: Day 0: CIDR inserted, Day 5: CIDR removed, prostaglandin (PG)F2α treatment (500μg cloprostenol), Day 6: PGF2α treatment, Day 8: GnRH (100μg of gonadorelin). On Day 0, at the time of CIDR insertion, heifers were assigned in a completely randomised design to the following groups: Single (a single dose of GnRH; 100μg of gonadorelin), Double (200μg of gonadorelin) or No GnRH (control). All heifers received an Estrotect patch placed on Day 5 and evaluated for signs of oestrus on Day 8. At location A, heifers were evaluated by ultrasonography 5 days after GnRH to determine presence and size of corpus luteum (CL), whereas at location B presence and location of CL were determined by transrectal palpation at the time of transfer. Heifers with a CL received an embryo 7±1 days after GnRH administration, and pregnancy was determined by ultrasonography 41 and 63 days after GnRH. Data were analysed by generalized linear mixed models. Oestrus expression was greater in heifers that received Single and Double GnRH than in the No GnRH group (P=0.001). Similarly, utilisation rate (number transferred per number treated) was greater for heifers in the Single and Double GnRH group than for those in the No GnRH group (P=0.02). Pregnancy data were analysed for a subset of recipients using data from Day 41 (n=2267) and Day 63 (n=2042). The analysis of fertility outcomes included as covariates the type of embryo (invitro fresh or frozen and invivo fresh or frozen), embryo stage, embryo quality, interval from GnRH to transfer, and oestrus expression. Pregnancies per embryo transfer (P/ET) at Days 41 and 63 were not different between treatment groups (P=0.86), and there was no interaction between type of embryo and treatment (P&amp;gt;0.15). Pregnancy loss between Days 41 and 63 was not different (P=0.49) between treatments groups. In conclusion, the removal of the initial GnRH from a 5-day FTET protocol resulted in a slight but significant reduction in the utilisation rate and the percentage of heifers showing oestrus. However, there was no detrimental effect on fertility. As a result, the overall cost of the FTET program can be reduced by eliminating the need for the initial GnRH treatment without compromising fertility. Table 1.Reproductive performance in recipients receiving different doses of gonadotrophin-releasing hormone (GnRH) at initiation of the synchronization protocol Treatment Oestrus (n) Utilisation rate (n) P/ET1 D41 (n) P/ET D63 (n) Pregnancy loss (n) No GnRH 69.2%B (621/898) 85.0%B (763/898) 41.6% (308/740) 39.9% (268/672) 4.3% (12/280) Single GnRH 76.1%A (685/900) 88.8%A (799/900) 42.7% (329/770) 39.5% (272/689) 6.5% (19/291) Double GnRH 75.3%A (671/891) 88.7%A (790/891) 41.5% (314/757) 38.9% (265/681) 5.4% (15/280) A,BValues with different superscripts within a column differ (P&amp;lt;0.05). 1P/ET=pregnancies per embryo transfer.

108 Use of seminal plasma as ovulation inductor in alpacas (Vicugna pacos) embryo recipient and its effect on pregnancy rate

Alpacas, like other camelids, are classified as induced ovulators because an external stimulus is required for the occurrence of ovulation. Recent studies have identified the β-nerve growth factor (β-NGF), a protein present in the seminal plasma (SP), as responsible for inducing ovulation in this species and having potent luteotropic function. We speculate that SP can be used in reproductive biotechnologies, such as embryo transfer (ET), to increase the number of genetically superior animals produced in breeding programs. The objective of this study was to evaluate the effect of inducing ovulation with SP or a gonadotrophin-releasing hormone (GnRH) analogue on pregnancy rate in recipients of an alpaca ET program. Semen from 5 adult male alpacas was collected with an artificial vagina and diluted 1:1 (v/v) with phosphate-buffered saline (PBS; Gibco-BRL). The diluted semen was centrifuged for 30min at 1200g, and the supernatant or SP was decanted and examined for absence of sperm. Then, the SP was centrifuged again for 20min at 1200×g. The SP was stored at −80°C until the use. Female alpacas (n=38; 6-8 years) with a body condition score of 2.5-3.5 (scale 1-5) were used for the experiment. Animals were evaluated daily by transrectal ultrasonography to determine the presence of a dominant follicle ≥7mm and randomly assigned to one of two groups: (1) GnRH (n=20), 0.04mg of Buserelin acetate IM, or (2) SP (n=18): 1.0mL of seminal plasma IM. Seven days after GnRH or SP treatment (Day 0) the recipients received a fresh embryo. Alpaca donors (n=18) were given GnRH (0.04mg IM) and treated 36h later with 700IU of equine chorionic gonadotropin (ECG). Donors were mated with fertile males 5 days after ECG (Day 0 of recipients), and embryos were recovered 7 days later. Embryos of similar quality were assigned to both groups and transferred nonsurgically to the uterine horn ipsilateral to the corpus luteum. Ultrasonography examinations were performed on Day 2 to confirm ovulation and Day 25 to determine pregnancy in all of the recipients. Data was analysed by chi-squared test. Ovulation rate was not different between groups (100% each). Pregnancy rate was 45% (9 out of 20) and 44% (8 of 18) in GnRH and SP groups, respectively (P=0.77). In conclusion, SP was effective to induce ovulation in alpacas and was able to produce a pregnancy rate similar to that of GnRH as an ovulation-inducing treatment. Thus, SP can be used as an alternative for ET programs in alpacas. Research was funded by the project Role of Seminal Plasma in Reproductive Physiology and Application of Biotechnologies in Camelids (149-2017-CIENCIACTIVA).

Optimal treatment for spermatogenesis in male patients with hypogonadotropic hypogonadism.

Background:To compare the efficacies of gonadotropin-releasing hormone (GnRH) pulse subcutaneous infusion with combined human chorionic gonadotropin and human menopausal gonadotropin (HCG/HMG) intramuscular injection have been performed to treat male hypogonadotropic hypogonadism (HH) spermatogenesis.Methods:In total, 220 idiopathic/isolated HH patients were divided into the GnRH pulse therapy and HCG/HMG combined treatment groups (n = 103 and n = 117, respectively). The luteinizing hormone and follicle-stimulating hormone levels were monitored in the groups for the 1st week and monthly, as were the serum total testosterone level, testicular volume and spermatogenesis rate in monthly follow-up sessions.Results:In the GnRH group and HCG/HMG group, the testosterone level and testicular volume at the 6-month follow-up session were significantly higher than were those before treatment. There were 62 patients (62/117, 52.99%) in the GnRH group and 26 patients in the HCG/HMG (26/103, 25.24%) group who produced sperm following treatment. The GnRH group (6.2 ± 3.8 months) had a shorter sperm initial time than did the HCG/HMG group (10.9 ± 3.5 months). The testosterone levels in the GnRH and HCG/HMG groups were 9.8 ± 3.3 nmol/L and 14.8 ± 8.8 nmol/L, respectively.Conclusion:The GnRH pulse subcutaneous infusion successfully treated male patients with HH, leading to earlier sperm production than that in the HCG/HMG-treated patients. GnRH pulse subcutaneous infusion is a preferred method.

MON-LB051 Non-inferiority Clinical Trial on Gonadotropinversus Pulsatile Gonadotropin-releasing Hormone Infusion Therapy in Male Adolescent Patient with Congenital Hypogonadotropic Hypogonadism

Context We investigate the efficacy and safety of non-inferiority clinical trial for human chorionic gonadotropin/ human menopausal gonadotropin (HCG/HMG) versus pulsatile gonadotropin-releasing hormone (GnRH) which has not been evaluated on non-inferiority clinical trial in puberty boys with CHH. Objective To compare the efficacy and security of two different treatments in male adolescent patient with congenital hypogonadotropic hypogonadism (CHH) . To explore the standardization of early treatment and it is possible clinical recommended regimen. Methods For this prospective cohort nonrandomized controlled study, male adolescent CHH patients were recruited and categorized into HCG/HMG(group 1) and GnRH (group 2) groups. All patients were treated for 3-12months. The study was divided into research period (3 months of treatment) and extension period (3 to 12 months of treatment). Testicular volume (TV), penile length(PL), blood sex hormones levels, height, body weight, and other related laboratory indices were measured and evaluated. In this study, we observe the therapeutic effect within 3 months and also collect partial extended period data for providing further research experience. Results All CHH patients were treated for over 3 months. At the beginning, the average age of patients, the testicular volume, penile length, penile diameter in group 1 and group 2 were 15.3±1.9 years VS 14.2±1.5 years, 2.5±1.4ml VS 2.7±1.5ml, 4.8±1.3cm VS 4.2±1.4cm and 1.6±0.4cm VS 1.5±0.4cm. The difference of two groups was not statistically significant. After 3 months treatment, the testicular volume, penile length, penile diameter, the growth of testicular volume, the growth of penile length and the growth of penile diameter in group 1 and group 2 were 5.1±2.7ml VS 4.6±2.7ml , 6.9±1.7cm VS 5.1±1.6cm, 2.5±0.5cm VS 1.9±0.6cm,2.0±1.6 cm 和1.0±0.8cm, 0.9±0.5cmand0.3±0.4cm. The difference of two groups was not statistically significant. There was no significant difference in height, body weight, or BMI between the two treatments. Based on the principles of hypothesis-test, mean value M-0.25625, standard error(SE) = 0.69319,M±1.96, Se=-0.25625±1.3586524,(-1.161,1.10). The growth differential of testicular volume between group 1 and group 2 was less than 2ml in (P<0.05) . It can be inferred that group 1 is not inferior to group 2. There was no significant difference in efficacy comparison in some of the patients were treated after 6-12 months in both groups. There was no significant difference in side effects in both groups. Conclusions In this clinical trial, 3 months was an observation period. Short-term therapeutic indicated adolescent patients with CHH were effectively treated with HCG/HMG and GnRH. We discovered that the effect of HCG/HMG was as good as GnRH in treating adolescent boys with CHH. This therapeutic schedule can be used in more patients. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Timed artificial insemination plus heat II: gonadorelin injection in cows with low estrus expression scores increased pregnancy in progesterone/estradiol-based protocol

The use of tail chalk and estrus/heat expression scores (HEATSC) evaluation is instrumental in identifying cows with greater estrus expression and greater artificial insemination pregnancy rates (P/AI) in cows submitted to timed artificial insemination (TAI), and cows with low or no estrus expression present lower P/AI. It was intended in this study to improve the pregnancy rates in TAI for Bos indicus beef cows, and gonadotrophin-releasing hormone (GnRH) injection was hypothesized to increase pregnancy rates in a TAI program for cows submitted to progesterone–estradiol-based protocols with low or no estrus expression, evaluated by HEATSC. Cows (n= 2284) received a progesterone device and 2 mg estradiol benzoate, after 8 days the device was removed and 1 mg estradiol cypionate, 150 μg of d-cloprostenol and 300 IU equine chorionic gonadotropin was administered. All cows were marked with chalk and HEATSC evaluated (scales 1 to 3) at TAI performed on day 10. Animals with HEATSC1 and HEATSC2 (n= 937) received 100 μg de gonadorelin (GNRH group; n= 470), or 1 ml saline (Control group; n= 467), and cows with HEATSC3 (named HEAT group; n= 1347) received no additional treatment. The larger dominant follicle, evaluated on day 8and at TAI (day 10), was greater in HEAT group (P= 0.0145 and P <0.001, respectively). Corpus luteum (CL) area and progesterone concentration was evaluated on day 17, and CL area was larger in HEAT group, intermediary in Control and lower in GnRH group (Control= 2.68 cm2, GnRH= 2.37 cm2, HEAT group= 3.07 cm2, P <0.001). Greater progesterone concentrations were found in HEAT group than in Control and GnRH groups (Control= 4.74 ng/ml, GnRH= 4.29 ng/ml, HEAT group= 6.08 ng/ml, P<0.001). There was a difference in ovulation rate, greater in HEAT group than GnRH and Control groups (Control= 72.5%; GnRH= 81.25%; HEAT group= 90.71%; P= 0.0024). Artificial insemination pregnancy rates was greater in HEAT group (57.09% (769/1347) than in Control and GNRH groups, with positive effect of GnRH injection at the time of TAI in P/AI (Control= 36.18% (169/467), GnRH= 45.95% (216/470); P<0.0001). In conclusion, GnRH application in cows with low HEATSC (1 and 2) is a simple strategy, requiring no changes in TAI management to increase pregnancy rates in postpartum beef cows submitted to progesterone–estradiol-based TAI protocols, without reaching, however, the pregnancy rates of cows that demonstrate high estrus expression at the TAI.

Inducing ovulation with hCG in a five-day progesterone-based fixed-time AI protocol improves the fertility of anestrous dairy cows under heat stress conditions

This study compares the fertility effects of inducing ovulation using human chorionic gonadotropin (hCG) versus gonadotropin releasing hormone (GnRH) at the end of a 5-day progesterone(P4)-based protocol for fixed-time artificial insemination (FTAI) in heat-stressed and non-heat stressed anestrous lactating dairy cows. Heat stress (HS) was defined as an environmental temperature-humidity index (THI) > 72. A P4 intravaginal device (CIDR) was fitted for five days and GnRH administered upon CIDR insertion and a double dose (24 h apart) of prostaglandin F2α upon CIDR removal. Cows then received either GnRH (GnRH group; n = 506), or hCG (hCG group; n = 493) 36 h after CIDR removal and were inseminated 50–56 h after CIDR removal. Ovulation failure was investigated in a subset of 425 cows: 223 and 202 receiving GnRH and hCG, respectively. Based on odds ratios, the interaction between treatment and HS had a significant effect on the ovulation failure rate (P = 0.01). This meant that compared to the rates recorded in non-heat-stressed, GnRH-treated cows (13%), ovulation failure in heat-stressed GnRH-treated cows (25.3%) was more likely by a factor of 2.3 (P = 0.04), in non-heat-stressed hCG-treated cows (2.3%) was less likely by a factor of 0.16 (P = 0.02) and was not significantly different in heat-stressed hCG-treated cows (7%). Interactions between treatment and HS and between treatment and parity had a significant effect on the pregnancy rate (P = 0.0001 and P = 0.001, respectively). The treatment-HS interaction determined that compared to the rates recorded in non-heat-stressed, GnRH-treated cows (30.5%), pregnancy in heat-stressed GnRH-treated cows (17.6%) was less likely by a factor of 0.48 than the remaining cows (P = 0.001), whereas because of the treatment-parity interaction, compared to the rates recorded in primiparous, GnRH-treated cows (31.4%), pregnancy in GnRH-treated multiparous cows (18.9%) was less likely to conceive by a factor of 0.51 than the remaining cows (P = 0.002). No significant effects of treatment on the rates of pregnancy loss or twin pregnancy were identified by binary logistic regression. In conclusion, hCG treatment given at the end of a 5-day P4-based protocol for FTAI improved ovulation and pregnancy rates in anestrous cows under conditions of HS and also had a beneficial impact on the pregnancy rate in anestrous multiparous cows throughout the year.

62 Will Gonadotropin-Releasing Hormone Treatment Hasten the Onset of Puberty in Peripubertal Heifers?

Treatment with gonadotropin-releasing hormone (GnRH) has been used to induce ovulation in prepubertal heifers. The objective of this study was to evaluate whether peripubertal heifers will continue to ovulate at regular intervals (i.e. attain puberty) after GnRH treatment. Prepubertal crossbred Hereford heifers, 11.0 ± 0.5 months of age, 344 ± 26 kg of body weight, and at random stages of ovarian follicular wave status, were assigned to 2 groups (age- and weight-matched) and given GnRH (n = 24) or no treatment (Control, n = 22) on Day 0. Ovarian ultrasonography was performed every second day from Day 0 to 44 to record the size of 2 largest follicles and the corpus luteum (CL). Thereafter, examinations were done every 4 days until the third ovulation or Day 100, whichever came first. The first and second interovulatory intervals (IOI) were categorized as short (&lt;12 days), normal (16-24 days), or long (&gt;24 days), and the onset of the puberty was defined by the occurrence of 2 consecutive short or normal IOI (i.e. 3 uninterrupted ovulations). Proportional data were compared among groups by chi-squared test. Single-point measurements were compared by analysis of variance and multiple comparisons were made using Tukey’s test. Two heifers (one in each group) failed to ovulate during the experiment. The diameter of the largest follicle on Day 0 did not differ (P = 0.31) between the GnRH and Control groups (12.6 ± 0.37 mm and 13.1 ± 0.29 mm, respectively). The proportion of heifers that ovulated by Day 4 after treatment was higher in the GnRH than in the Control group (9/24 v. 1/22; P &lt; 0.01). However, the proportion of heifers in the GnRH v. Control groups that ovulated twice (19/24 v. 18/22; P = 0.60) or 3 times (9/24 v. 9/22; P = 0.81) did not differ. The age at first ovulation tended to be younger in the GnRH group than in the Control (12 ± 0.97 v. 13 ± 0.90 months; P = 0.07), but the effect was attributed only to those heifers that ovulated in response to GnRH treatment (n = 9). The age at first ovulation was 11.2 ± 0.50, 12.7 ± 0.73, and 12.6 ± 0.90 months in GnRH-responders, non-responders, and the control group, respectively (P &lt; 0.0001). One heifer that ovulated in response to GnRH treatment failed to ovulate again during the study period (Day 100). In 87.5% (7/8) of the heifers that responded to GnRH treatment and ovulated at least twice, the first IOI was long (55.5 ± 8.3 days). When data were combined between the GnRH non-responders and the control group (n = 35), the first IOI was short (8.9 ± 0.4 days) in 77% of the heifers, and the second IOI was of normal length (18.8 ± 0.9 days) in 93% of heifers. The age at the second ovulation in GnRH responders (12.7 ± 0.3 months) was similar (P = 0.82) to the age at first ovulation in GnRH non-responders (12.9 ± 0.1 months) and the control group (12.7 ± 0.2 months), indicating that GnRH treatment did not hasten the onset of continuous cyclicity. In conclusion, although GnRH treatment induced first ovulation in some peripubertal heifers, treatment did not hasten the onset of puberty. Research was supported by the Natural Sciences and Engineering Research Council of Canada.