GnRH analogue triptorelin acetate induces ovulation in jennies during oestrus.

Most of the northern hemisphere donkey breeds are faced with the risk of extinction, thus donkey reproduction is considered an emerging branch of theriogenology, and the management of artificial insemination and induction of ovulation is a crucial point in setting up preservation protocols. For four consecutive cycles, six jennies' ovarian activity was routinely monitored; an ultrasound examination was performed daily from the evidence of a follicle diameter ≥27 mm until ovulation. Upon reaching a follicular diameter ≥32 ± 2 mm (Hour 0), oestrous jennies were treated alternatively with 0.1 mg triptorelin acetate, sc, (TRIP), 0.4 mg/sc of buserelin acetate (BUS) or saline, sc, (CTRL) and examined ultrasonographically at Hours 14, 24, 38, 42, 48, 62 and every 24 h until ovulation. Induction of ovulation was considered successful if ovulation occurred from 24 to 48 h after treatment. 11/12 cycles resulted in ovulation for TRIP and 12/12 for BUS and CTRL groups, respectively. Mean ± SD ovulation time after treatment was 37.3 ± 8.3, 47.1 ± 21.0 and 66.8 ± 25.9 h for BUS, TRIP and CTRL, respectively (p = .0032). Ovulation rates between h24 and h48 were 10/12 (83.3%) for both TRIP/BUS and 2/12 (16.7%) for CTRL, respectively (p = .003). Buserelin and triptorelin-treated jennies had a 25 times higher probability to ovulate between Hours 24 and 48 than controls (p = .003), while there were no jenny and cycle effects on the ovulatory rate. The results of this study show how triptorelin successfully induced ovulation in jennies, like other GnRH analogues previously evaluated.

Cervix-Deep Rectal Temperature Differential on the Day of Ovulation is Correlated With Embryo Recovery Results in Mares.

Variations in temperature throughout the reproductive tract have been noted in many species. A recent study found the cervix-rectum temperature differential (CR-TD) in cattle was related to fertility. The present study aimed to assess the CR-TD in mares around the time of ovulation and relate it to embryo recover. Over 52 cycles, mares were inseminated with a fertile stallion and embryo recovery was undertaken on Day 7 post ovulation. Further 10 control mares were not inseminated. Rectal and cervical temperatures were measured using a precision thermometer on four or five occasions: the day of deslorelin administration and insemination, the day before ovulation, the day of ovulation (Day 0), the day after ovulation and, for inseminated mares, before embryo recovery on Day 7. One-way ANOVA showed that the CR-TD was significantly lower on the day of ovulation in the 36 positive cycles, in which an embryo was recovered, versus the 16 in which the embryo flush was negative (0.21 ± 0.17 vs. 0.40 ± 0.09°C; p < 0.001). Control cycles showed equivalent CR-TD to positive (0.13 ± 0.22 vs. 0.21 ± 0.17°C; p = 0.196) but not negative cycles (0.13 ± 0.22 vs. 0.40 ± 0.09°C; p < 0.001). A positive embryo recovery was associated with lower CR-TDs from the time of insemination and deslorelin to the day after ovulation compared to the day of embryo flushing (RM ANOVA; p < 0.001; Pairwise comparisons; p ≤ 0.01, in all cases). Rectal or cervical temperatures per se showed no significant differences between positive, negative or control cycles at any time point. In conclusion, a thermoregulatory process occurs close to ovulation which results in a lower CR-TD in cycles that produced an embryo versus those which did not. Further characterisation of TDs within the reproductive tract of the mare would increase our understanding of the conditions required for optimum fertility.

Effect of pre-treatment with deslorelin on the ovarian response of ewes superovulated with FSH.

This study evaluated the use of the GnRH agonist hormone, deslorelin, to control the follicular population before initiating multiple ovulation and embryo transfer (MOET) treatment. Twenty-four cross-bred Santa Inês ewes, aged between 2 and 4 years, were randomly assigned to either a control group (n = 11) or a treated group (n = 13). All ewes received an intravaginal device containing 60 mg of medroxyprogesterone acetate on day 0, and a new device on day 7, which remained in place until day 14. Additionally, the ewes were administered 125 µg of cloprostenol on day 7. The superovulatory treatment involved administering 200 mg of pFSH, divided into eight decreasing doses at 12-h intervals starting on day 12. On day 14, 300 IU of eCG was administered. In the deslorelin group, three doses of 100 µg of deslorelin were administered starting on day 3 after the insertion of the vaginal device, with subsequent doses given at 72-h and 144-h intervals. Natural mating was performed 36 h after the removal of the progesterone implant using males with proven fertility. Embryo collection took place on the 6th day after mating, and the recovered structures were quantified and evaluated for quality and developmental stage. Transrectal ultrasonography was conducted on days 12, 16 and 21 to evaluate the ovaries, specifically to assess the ovarian follicular population and the presence of the corpus luteum. Ewes in the control group had higher embryo recovery rates (p < .01) compared to the treated group (5.2 ± 0.8 vs. 1.1 ± 0.8), with differences observed primarily in the number of morulae. The number of corpus luteum observed during the laparotomy on day 21 was significantly higher (p < .01) in the control group (10.44 vs. 4.5 corpus luteum per ewe). Yet, the treated group had a significantly higher number of follicles (p < .05) on the first day of pFSH application (5.5 vs. 3.0 follicles per ewe). In conclusion, although the inclusion of deslorelin in the superovulation protocol resulted in increased synchronization of oestrus and follicle number, it did not lead to an increase in the number of corpus luteum or harvested embryos.

Potency evaluation of different GNRH analogues on ovulation induction and reproductive performance of doe rabbit.

Gonadotropin-releasing hormone (GnRH) -supplemented extenders have emerged as a welfare-orientated method to induce ovulation in the artificial insemination (AI) of rabbits. The main factor that limits the bioavailability of GnRH analogue on intravaginal administration is the proteolytic activity of enzymes present in rabbit seminal plasma. The use of GnRH analogues with higher biological potency would allow us to decrease their concentration in the seminal dose without compromising effectiveness. The current study was designed to assess the efficacy of various GnRH analogues concerning their ability to induce ovulation in rabbit AI. The base solution used for experimental extenders contained an aminopeptidase inhibitor. Four experimental groups were used, females from the Control group were induced to ovulate with an intramuscular administration of 1 µg of buserelin, while in the other three groups females received an intravaginal administration of 3.5 µg of buserelin (BUS), deslorelin (DES) or fertirelin (FER) within the seminal dose. Results showed that the ovulation frequency was similar in all groups studied. A concentration of 3.5 µg of the different GnRH analogues tested in this study showed similar potency in inducing ovulation in non-lactating females, yielding comparable results in terms of pregnancy rate at birth and prolificacy.

Effects of water-soluble additive on the release profile and pharmacodynamics of triptorelin loaded in PLGA microspheres.

A satisfactory drug release profile for gonadotropin-releasing hormone (GnRH) agonist drugs is high initial release followed by small amount of drug release per day. In the present study, three water-soluble additives (NaCl, CaCl2 and glucose) were selected to improve the drug release profile of a model GnRH agonist drug-triptorelin from PLGA microspheres. The pore manufacturing efficiency of the three additives was similar. The effects of three additives on drug release were evaluated. Under the optimal initial porosity, the initial release amount of microspheres containing different additives was comparable, this ensured a good inhibitory effect on testosterone secretion in the early stage. For NaCl or CaCl2 containing microspheres, the drug remaining in the microsphere depleted rapidly after the initial release. The testosterone concentration gradually returned to an uncontrolled level. However, for glucose containing microspheres, it was found that the addition of glucose could not only increase the initial release of the drug but also assist in the subsequent controlled drug release. A good and long-time inhibitory effect on testosterone secretion was observed in this formulation. The underlying cause why the incorporation of glucose delayed the subsequent drug release was investigated. SEM results showed that considerable pores in glucose containing microspheres were healed during the microspheres incubation. After thermal analysis, an obvious glass transition temperature (Tg) depression was observed in this formulation. As Tg decreased, polymer chains are able to rearrange at lower temperatures. This, morphologic change was reflected in the gradual closure of the pores, and is the likely reason that drug release slowed down after the initial release.HIGHLIGHTSThe addition of glucose could not only increase the burst release of the drug but also delay the subsequent drug release.High initial burst and a sustained drug release helped obtain a good inhibitory effect on testosterone secretion.As Tg decreased, polymer chain was prone to rearrange. Morphologic change was reflected in the gradual closure of the pores. This was the reason that drug release slowed down after the initial burst.

EFFECTS OF A GNRH VACCINE AND DESLORELIN ACETATE IMPLANTS IN MALE FRESHWATER STINGRAYS (POTAMOTRYGON SP.).

Very little information is available in veterinary literature concerning chemical contraception in elasmobranchs. To decrease breeding and adverse reproductive behaviors, male Potamotrygon sp., housed in two zoologic institutions, were treated using methods used in other elasmobranchs. Four animals received deslorelin acetate implants (Suprelorin 4.7 mg and 9.4 mg), four animals received a gonadotropin-releasing hormone vaccine (Improvac 50-100 µg) twice separated by 1 mon, and two animals were not treated to serve as controls. Health checks, including blood sampling, coelomic ultrasound, and sperm analysis, were performed bimonthly and then monthly over almost 2 yr. Microscopic examination of sperm never revealed any significant change in concentration or motility. Size of testes and seminal vesicles glands did not change significantly after treatment. Plasma testosterone concentrations were stable (∼1 ng/ml) in intact and vaccinated animals throughout the study period. Plasma testosterone level increased significantly after deslorelin implantation and remained very high for at least 13 mon, never returning to initial values. Peak concentration varied according to the deslorelin acetate concentration used. Aggression toward females continued despite the use of contraception. Histopathologic examination on dead stingrays revealed active testicular tissue. These results suggest that deslorelin acetate implants and GnRH vaccine are ineffective at dosages used in our cases. Implants caused a continuous stimulation of the hypothalamic-pituitary-gonadal axis that could be harmful for the animals.

Resumption of ovarian activity following removal of a 4.7 mg deslorelin implant in queens.

Deslorelin implants are widely used in felines. Due to their prolonged duration cat breeders frequently request early implant removal. The interval between deslorelin implant removal and resumption of ovarian function in queens is unknown. The aim of this study was to evaluate the interval between the removal of a deslorelin implant and the resumption of ovarian activity in adult queens. Twenty-three queens were treated with a 4.7 mg deslorelin implant placed in the periumbilical area. In the 16 queens completing the study implants were surgically removed at 3, 6 or 9 months (n = 6, 4 and 6 queens, respectively). Queens received a GnRH stimulation test as part of their pre-treatment general and reproductive health check. Following implantation treatment, all queens in inter-oestrus-anoestrus at the time of treatment came in oestrus within 2-5 days. Starting 7-14 days following implant removal queens were checked every 1-2 weeks with reproductive ultrasonography, a vaginal smear and blood collection. The interval to resumption of ovarian function ranged from 3 to 7 weeks irrespective of treatment length and age of the queen but was longer when the implant was removed at decreasing photoperiod (p < .05). In conclusion, at least 3 weeks post-removal are needed during increasing photoperiod to achieve follicular development and oestrogen production sufficient to support oestrous behaviour in queens following removal of a 4.7 mg deslorelin implant, while this time may increase up to 7 weeks during decreasing photoperiod. Further studies are needed to assess the interval between removal of a deslorelin implant and occurrence of ovulation as well as fertility at the first oestrus after a deslorelin treatment.

An assessment of the protective effect of gonadotropin-releasing hormone agonist and antagonist on bleomycin-induced ovarian toxicity in rats.

The aim of this study is to evaluate the effect of GnRH agonist or GnRH antagonist therapy on bleomycin-administered rats by examining ovarian follicle counts and AMH levels. A total of 30 female Wistar albino rats aged 4-6 months were randomly divided into 4 groups. First, an intramuscular injection of bleomycin (30 mg/m2) was administered to all except the control group on the 1st, 8th and 15th days. The control group (Group I) was administered 0.1 mL intramuscular saline on those days. The bleomycin group (Group II) was followed up without any further treatment. The bleomycin + GnRH agonist group (Group III) was administered subcutaneous GnRH agonist triptorelin (1 mg/kg) at the same time as the bleomycin injections. The bleomycin + GnRH antagonist group (Group IV) was administered 1 mg/kg cetrorelix acetate subcutaneously, concurrently with the bleomycin. Although AMH levels were lower in the bleomycin group than in all the other groups, there was no statistically significant difference between the groups in terms of AMH levels (p > .05). In the bleomycin + cetrorelix acetate and bleomycin + triptorelin groups, significantly higher primordial, secondary and tertiary follicle counts were determined compared to the bleomycin group (p < .001). In conclusion the harmful effects of bleomycin on ovarian reserve can be reduced by the simultaneous administration of GnRH agonist or GnRH antagonist.

The past, present and future of hormonal contraceptive use in managed captive female tiger populations with a focus on the current use of deslorelin acetate.

Tigers (Panthera tigris spp.) are endangered in the wild; ensuring sustainable insurance populations requires careful planning within zoological collections. In captive situations, contraceptives are often used to control breeding and ensure genetically viable populations that contain manageable numbers of animals; reversible contraceptives are ideal because they offer flexibility for breeding management. Historically, synthetic progestins, such as melengestrol acetate implants, were used in female tigers, but these are associated with an increased risk of reproductive pathology and subsequent infertility. Recent management advice to ex-situ collections has been to transition to the use of gonadotropin-releasing hormone agonists, such as deslorelin acetate implants, which do not appear to have a similar risk of reproductive pathology but are associated with highly variable reversal times in exotic felids. Using data from 917 contraceptive records in female tigers captured by the Association of Zoos and Aquariums Reproductive Management Center and the European Association of Zoos and Aquaria Reproductive Management Group's joint Contraception Database and from supplementary surveys, this study reviews the changing use of contraceptives in captive female tigers. The aim was to describe the historical and current use of contraceptives and provide a comprehensive assessment on the use of deslorelin implants, including data on product protocols, efficacy, pathology, and reversibility. This study determined that current dose, frequency, reversibility, and anatomical placement sites of deslorelin implants are highly variable, indicating that specific, readily available, unified, evidence-based recommendations on the use of deslorelin would be useful for future contraceptive use in managed tiger populations.

GnRH antagonist alters the migration of endometrial epithelial cells by reducing CKB.

Some studies have demonstrated that the implantation rate of fresh transfer cycles is lower in the gonadotropin-releasing hormone antagonist (GnRH-ant) protocol than in the GnRH agonist (GnRH-a) protocol during in vitro fertilization (IVF). This effect may be related to endometrial receptivity. However, the mechanisms are unclear. Here, endometrial tissues obtained from the mid-secretory phase of patients treated with GnRH-a or GnRH-ant protocols and from patients on their natural cycle were assessed. Endometrial expression of B-type creatine kinase (CKB), which plays important roles in the implantation phase, was significantly reduced in the GnRH-ant group. At the same time, expression of the endometrial receptivity marker HOXA10 was considerably reduced in the GnRH-ant group. GnRH-ant exposure in endometrial epithelial cells (EECs) in vitro decreased CKB expression and ATP generation and blocked polymerization of actin. Furthermore, in vitro GnRH-ant-exposed Ishikawa cells showed enhanced F-actin depolymerization, and these effects were rescued by CKB overexpression. Similar effects were observed after CKB knockdown, and these effects were rescued by CKB overexpression. Moreover, cell migration was decreased in CKB-knockdown Ishikawa cells compared with that in control cells, and this effect was also rescued by CKB overexpression. Overall, these findings showed that GnRH-ant affected CKB expression in EECs, resulting in cytoskeletal damage and migration failure. These results provide insight into the roles and molecular mechanisms of GnRH-ant treatment in the endometrium.

Deslorelin acetate implant induces transient sterility and behavior changes in male olive baboon (Papio anubis): A case study.

This case study evaluates the effects of a 4.7 mg deslorelin acetate implant on one male olive baboon (Papio anubis). Implantation induces transient azoospermia after which the subject was able to conceive again. Behavior was also impacted with a decrease in our proxies of aggressiveness and sexual arousal.

Single injection of triptorelin or buserelin acetate in saline solution induces ovulation in mares the same as a single injection of hCG.

The aim of this study was to assess the efficacy of different doses of buserelin acetate and another GnRH agonist, triptorelin acetate, in saline solution in a single subcutaneous injection, to induce ovulation of growing pre-ovulatory follicle in mare and compare it with the classical treatment of a single injection of hCG. The study is split into 3 experiments over different breeding seasons in the same stud with a random distribution of treatment. The first one was to compare the injection of 6 mg of buserelin with 1,500 IU of hCG; the second one consisted of comparing different doses of buserelin (6 mg and 3 mg); and the third one compared three different doses of buserelin (3, 2 and 1 mg), 0.1 mg of triptorelin with 1,500 IU of hCG as a control group. The results of all experiments showed the same efficacy between all treatments with mares ovulating between 24 and 48 hr after injection: experiment 1: hCG (78% n = 41) and buserelin 6 mg (90% n = 50); experiment 2: buserelin 6 mg (78,1% n = 192) and buserelin 3 mg (78% n = 341); and experiment 3: hCG (87% n = 106), buserelin 3 mg (84,7% n = 137), buserelin 2 mg (82,7% n = 104), buserelin 1 mg (87% n = 54) and triptorelin 0.1 mg (84,7% n = 72). In conclusion, this study contributes to erasing the dogma that has been established since 1975 that a single injection in solution without any long-acting excipient of a GnRH agonist cannot induce ovulation in the mare. This study also shows that a injection of 0.1 mg of triptorelin in solution is a good alternative for ovulation induction and is comparable to small doses of buserelin acetate in solution (1 mg) and 1,500 IU of the gold standard trigger hCG, mainly in countries where human formulation of buserelin is not available.

Is oocyte maturation rate associated with triptorelin dose used for triggering final oocyte maturation in patients at high risk for severe ovarian hyperstimulation syndrome?

STUDY QUESTION: Are oocyte maturation rates different among 0.1, 0.2 and 0.4 mg triptorelin used for triggering final oocyte maturation in patients at high risk for ovarian hyperstimulation syndrome (OHSS) undergoing ICSI? SUMMARY ANSWER: A dose of 0.1 mg triptorelin results in similar oocyte maturation rates compared to higher doses of 0.2 and 0.4 mg in patients at high risk for OHSS undergoing ICSI. WHAT IS KNOWN ALREADY: The GnRH agonist triptorelin is widely used instead of hCG for triggering final oocyte maturation, in order to eliminate the risk of severe OHSS in patients undergoing ovarian stimulation for IVF/ICSI. However, limited data are currently available regarding its optimal dose use for this purpose in patients at high risk for OHSS. STUDY DESIGN, SIZE, DURATION: A retrospective study was performed between November 2015 and July 2017 in 131 infertile patients at high risk for severe OHSS undergoing ovarian stimulation for ICSI. High risk for severe OHSS was defined as the presence of at least 19 follicles ≥11 mm in diameter on the day of triggering final oocyte maturation. PARTICIPANTS/MATERIALS, SETTING, METHODS: Ovarian stimulation was performed with recombinant FSH and GnRH antagonists. Patients received 0.1 (n = 42), 0.2 (n = 46) or 0.4 mg (n = 43) triptorelin for triggering final oocyte maturation. Hormonal evaluation of FSH, LH, estradiol (E2) and progesterone (PRG) was carried out on the day of triggering final oocyte maturation, 8 and 36 hours post triggering and 3, 5, 7, and 10 days after triptorelin administration. During this period, all patients were assessed for symptoms and signs indicative of severe OHSS development. Primary outcome measure was oocyte maturation rate, defined as the number of metaphase II (MII) oocytes divided by the number of cumulus-oocyte-complexes retrieved per patient. Results are expressed as median (interquartile range). MAIN RESULTS AND THE ROLE OF CHANCE: No significant differences in patient baseline characteristics were observed among the 0.1 mg, the 0.2 mg and the 0.4 mg groups. Regarding the primary outcome measure, no differences were observed in oocyte maturation rate among the three groups compared [82.6% (17.8%) versus 83.3% (18.8%) versus 85.1% (17.2%), respectively, P = 0.686].In addition, no significant differences were present among the 0.1 mg, 0.2 mg and 0.4 mg groups, regarding the number of mature (MII) oocytes [21 (13) versus 20 (6) versus 20 (11), respectively; P = 0.582], the number of oocytes retrieved [25.5 (13) versus 24.5 (11) versus 23 (12), respectively; P = 0.452], oocyte retrieval rate [81.0% (17.7%) versus 76.5% (23.5%) versus 75.0% (22.5), respectively; P = 0.088], the number of fertilized (two pronuclei) oocytes [12.5 (9) versus 14.5 (7) versus 14.0 (8), respectively; P = 0.985], fertilization rate [71.7% (22%) versus 77.1% (19.1%) versus 76.6% (23.3%), respectively; P = 0.525] and duration of luteal phase [7 (1) versus 8 (2) versus 7 (1) days, respectively; P = 0.632]. Moreover, no significant differences were present among the three triptorelin groups regarding serum levels of LH, FSH, E2 and PRG at any of the time points assessed following triggering of final oocyte maturation. LIMITATIONS, REASONS FOR CAUTION: This is a retrospective study, and although there were no differences in the baseline characteristics of the three groups compared, the presence of bias cannot be excluded. WIDER IMPLICATIONS OF THE FINDINGS: Based on the results of the current study, it appears that triggering final oocyte maturation with a lower (0.1 mg) or a higher dose (0.4 mg) of triptorelin, as compared to the most commonly used dose of 0.2 mg, does not confer any benefit in terms of oocyte maturation rate in patients at high risk for severe OHSS. STUDY FUNDING/COMPETING INTEREST(S): No external funding was obtained for this study. There are no conflicts of interest.

GnRH agonists to sustain the luteal phase in antagonist IVF cycles: a randomized prospective trial.

BACKGROUND: The addition of a GnRH analogue to the luteal phase in in vitro fertilization programs has been seldom proposed due to the presence of GnRH receptors in the endometrium. The aim of the study was to evaluate the effect of triptorelin addition in short antagonist cycles, compared to cycles where the only supplementation was progesterone. METHODS: The primary objective of this study was the study of the effect of Triptorelin addiction during the luteal phase on the live birth rate. Secondary objectives of efficacy were pregnancy rates and implantation rates, as well as safety in terms of OHSS risks. The study was a prospective, randomized, open study, performed in two independent Centers from July 2013 to October 2015. Patients were divided into three groups: a) Regular antagonist protocol, with only luteal progesterone; b) Antagonist protocol with luteal triptorelin as multiple injections, c) Antagonist protocol with luteal triptorelin as single bolus. Descriptive statistics were obtained for all the parameters. Mean and standard deviation were used for all quantitative parameters. Differences between percentages were studied using Chi-square test generalized to the comparison of several proportions. RESULTS: A total number of 1344 patients completed the study, 786 under the age of 35 years, and 558 over 35 years. It was observed an increase of positive HCG results, Clinical pregnancy rates and Delivery rates when triptorelin was added in the luteal phase, irrespective whether as a single bolus or five injections. This increase was statistically significant both for pregnancy rates and delivery rates. The statistic difference between pregnancies and deliveries obtained with or without luteal triptorelin reached p < 0,01. No increase of OHSS risk was observed. CONCLUSIONS: From this large study it appears that the concept of luteal phase supplementation should be revisited. From our study it appears that triptorelin addition to the luteal phase of antagonist cycles, either as a single bolus or using multiple injections, is a good tool to optimize ART results. TRIAL REGISTRATION: The study was approved by the Ethics Committee of Provincia di Bergamo (n 1203/2013).

Contraceptive efficacy and dose-response effects of the gonadotrophin-releasing hormone (GnRH) agonist deslorelin in Tasmanian devils (Sarcophilus harrisii).

Contraception is increasingly used to manage breeding opportunities in conservation-dependent species. This study aimed to determine the efficacy, duration of effect, optimal dose and potential side effects of Suprelorin contraceptive implants in Tasmanian devils, for use in the conservation breeding program. In our pilot study, Suprelorin was found to effectively suppress oestrous cycles in female devils, yet caused a paradoxical increase in testosterone in males. Therefore, we focussed on females in further trials. Females received one (n=5), two (n=5) or no (n=5) Suprelorin implants, with quarterly gonadotrophin-releasing hormone (GnRH) challenges used to test pituitary responsiveness over two breeding seasons. Both Suprelorin doses suppressed pituitary responsiveness for at least one breeding season, with a reduced effect in the second. There was a dose-response effect on duration rather than magnitude of effect, with high-dose devils remaining suppressed for longer than low-dose animals. There were no apparent negative effects on general health, yet captivity and contraception together may cause weight gain. Suprelorin contraceptive implants are now routinely used in the Save the Tasmanian Devil Program insurance metapopulation to meet the aims of maintaining genetic and behavioural integrity by controlling individual reproductive contributions in group housing situations.

GnRH-agonist deslorelin implant alters the progesterone release pattern during early pregnancy in gilts.

The aim of this study was to investigate the relationship of progesterone (P) and luteinizing hormone (LH) during recognition and establishment of pregnancy in the gilt. Therefore, the effects of eliminating episodic LH pulses on P patterns were determined during early pregnancy. To this end, a slow-release GnRH implant deslorelin was used for GnRH down-regulation. A group of gilts (GnRHa, n = 8) was implanted with the GnRH-agonist on Day 11 of pregnancy, while a control group (C, n = 5) was treated with a non-impregnated placebo implant. Blood was collected via a vena cava caudalis catheter at 10-min intervals for 8 hr on Day 16 and 21 of pregnancy. As expected, the GnRH implant reduced LH secretion (p < 0.01) and abolished LH pulses completely at Day 16 and Day 21 of pregnancy. On Day 16, there was no difference in P levels between the treatments. However, on Day 21, the GnRH-agonist treatment led to significantly increased P concentrations (p < 0.01) compared with the control gilts. Progesterone was secreted in a pulsatile manner in both treatment groups and no relationship between LH pulsatility and P pulsatility was observed. In conclusion, abolishment of LH pulsatility did not affect the pulsatile pattern of P secretion but led to an unexpected overall increase in P on Day 21 of pregnancy; this effect was delayed and occurred 10 days after commencing treatment with the GnRH depot agonist. The elevation of P on Day 21 of pregnancy in the GnRHa group suggests either a reduced negative feedback effect or an increased autocrine response by the corpora lutea.

Investigation of the efficacy of the GnRH agonist deslorelin in mitigating intraspecific aggression in captive male Amur leopards (Panthera pardus orientalis).

Housing bachelor groups is a necessary aspect of the care and husbandry of non-breeding individuals in zoological collections. Intraspecific aggressive behaviors may occur in this setting despite management strategies designed to mitigate these behaviors. Androgens (including testosterone) are associated with aggression in male species and interventional techniques to alter the animals' physiology to modify aggressive behavior are sometimes required. When agonistic behavior and physical aggression in two mature male Amur leopards housed together at Tayto Park escalated, despite all strategic management involvements, further intervention to moderate aggression was required. The gonadotropin-releasing hormone (GnRH) agonist, deslorelin, has been found to be effective in reducing androgens in domestic and non-domestic carnivores. We hypothesized that deslorelin's suppressive effect on hypothalamic-pituitary-gonadal axis would mitigate intraspecific aggression in two male intact leopards. Behavioral observations were carried out pre- and post-implant implantation of 9.4 mg deslorelin implant. The frequency of agonistic/aggressive behaviors for both leopards declined significantly (p < 0.05), as did marking behaviors post-implantation (p < 0.001). The insertion of deslorelin implants in two male intact leopards demonstrating increased frequency and severity of aggressive behaviors resulted in a reduction of the frequency of these behaviors. Deslorelin implantation should be considered for management of interspecific aggression of intact male leopards in bachelor groups.

Efficacy and Safety of gonadotropin-releasing hormone (GnRH) Agonists Triptorelin Acetate and Cetrorelix Acetate in Assisted Reproduction.

BACKGROUND The aim of this study was to compare the efficacy and safety of 2 GnRH agonists - triptorelin acetate and cetrorelix acetate - in assisted reproduction. MATERIAL AND METHODS A total of 182 females who received in vitro fertilization and embryo transfer (IVF+ET) from March 2014 to July 2014 were involved, and their clinical data were retrospectively analyzed. Among them, 91 patients received treatment with short-acting triptorelin (group A) and another 91 patients were treated with cetrorelix acetate (group B). Fasting blood was extracted from each patient on the day of administration of human chorionic gonadotropin (hCG), and serum levels of luteinizing hormone (LH), estradiol (E2), and progesterone (P) were detected using chemiluminescence method. The number of oocytes, fertilization rate, cleavage rate, and number of obtained embryos were recorded and compared. Pregnancy outcomes and adverse events were observed and compared. Expression level of FSH receptor (FSHR) in endometrial tissues was measured by qRT-PCR. RESULTS Serum level of E2 was significantly lower in group B than in group A (p<0.05). Indices, including the number of oocytes, fertilization rate and cleavage rate, number of obtained embryos, and pregnancy rate, were slightly better in group B than in group A, but no significant differences were found. The incidence of ovarian hyperstimulation syndrome (OHSS) was significant higher in group A than in group B (p<0.05). FSHR expression level was significantly lower in group B than in group A. CONCLUSIONS The effect of cetrorelix acetate is superior to that of short-acting triptorelin in assisted reproduction. Our most important finding is that cetrorelix acetate reduced the incidence of OHSS.

Transplantation of bovine adrenocortical cells encapsulated in alginate.

Current treatment options for adrenal insufficiency are limited to corticosteroid replacement therapies. However, hormone therapy does not replicate circadian rhythms and has unpleasant side effects especially due to the failure to restore normal function of the hypothalamic-pituitary-adrenal (HPA) axis. Adrenal cell transplantation and the restoration of HPA axis function would be a feasible and useful therapeutic strategy for patients with adrenal insufficiency. We created a bioartificial adrenal with 3D cell culture conditions by encapsulation of bovine adrenocortical cells (BACs) in alginate (enBACs). We found that, compared with BACs in monolayer culture, encapsulation in alginate significantly increased the life span of BACs. Encapsulation also improved significantly both the capacity of adrenal cells for stable, long-term basal hormone release as well as the response to pituitary adrenocorticotropic hormone (ACTH) and hypothalamic luteinizing hormone-releasing hormone (LHRH) agonist, [D-Trp6]LHRH. The enBACs were transplanted into adrenalectomized, immunodeficient, and immunocompetent rats. Animals received enBACs intraperitoneally, under the kidney capsule (free cells or cells encapsulated in alginate slabs) or s.c. enclosed in oxygenating and immunoisolating ßAir devices. Graft function was confirmed by the presence of cortisol in the plasma of rats. Both types of grafted encapsulated cells, explanted after 21-25 d, preserved their morphology and functional response to ACTH stimulation. In conclusion, transplantation of a bioartificial adrenal with xenogeneic cells may be a treatment option for patients with adrenocortical insufficiency and other stress-related disorders. Furthermore, this model provides a microenvironment that ensures 3D cell-cell interactions as a unique tool to investigate new insights into cell biology, differentiation, tissue organization, and homeostasis.

Pre-pubertal treatment with a GnRH agonist in bitches-Effect on the uterus and hormone receptor expression.

Aim of the study was to examine the effect of deslorelin on uterine tissues of eleven pre-pubertal bitches aged 4.2 ± 0.6 m. Implants containing placebo (sodium chloride 0.9%; n = 4, G I), 4.7 mg (n = 3, GII) or 9.4 mg (n = 4, GIII) deslorelin acetate (Suprelorin® ; Virbac, France), were administered subcutaneously. Signs of oestrus, vaginal cytology, serum progesterone (P4) and estradiol-17ß (E2) concentrations were monitored until the occurrence of oestrus. Bitches were ovariohysterectomized and sections from the uterine tissue were subjected to immunohistochemistry (IHC) for detection of GnRH receptor (R), Kisspeptin (KP)10, Kisspeptin receptor (GPR54), androgen receptor (AR), oestrogen receptor (ER) α,ß, and progesterone receptor (PR). Tissue sections were scored semi-quantitatively using an immunoreactivity score (IRS) ranging from 0 to 300 (3). Since some animals were ovariohysterectomized before puberty (n = 1 from GII and n = 2 from GIII), and some in metestrus (all controls and 2 from GII and GIII each), results from these animals were separately evaluated and compared to the controls. Results: No abnormalities were seen in uterine tissues. Kisspeptin 10 expression was low in all cell types, highest IRS were seen in the vascular endothelial cells. The GPR54 was mainly detected in the luminal epithelial cells, superficial and deep uterine glands. The expression of GPR54 and ERα,ß was especially high in bitches operated prepubertally. No difference was observed between the controls and experimental bitches operated in their first metestrus. The PR and ERα,ß were exclusively expressed in superficial and deep uterine glands and luminal surface epithelial cells. The AR and GnRH-R expression was negative in all cells of all groups. We conclude that application of 4.7 or 9.4 mg deslorelin at the age of 4 months did not cause uterine disturbances. GPR54 expression might be influenced by pre-pubertal deslorelin treatment or the changings related to approaching puberty; the latter is supposed in case of ERα,ß.