Pregnant Mare Serum Gonadotropin Treatment Research Articles

Hormonal dependent expression of apelin and apelin receptor in the ovary and uterus of mice

Apelin and APJ have been shown to regulate female reproductive functions. However, its uterine expression during the oestrous cycle and its regulation by ovarian steroids, along with gonadotropin regulation in the ovary, has not been investigated. This study aimed to analyze the steroid-dependent uterine expression of apelin/APJ in the uterus along with the oestrous cycle. Furthermore, it also aimed to investigate gonadotropin-dependent ovarian expression of apelin and APJ. To investigate the uterine expression of apelin and APJ during estrous cycle in mice, uterus at different estrous stage were collected. To explore the ovarian steroids dependent expression of apelin system in the uterus, ovariectomized mice were treated with only estrogen at dose of 30 ng/g, only progesterone at dose of 150 μg/g and combined doses. To study the effect of gonadotropin on ovarian expression of apelin system, immature mice were injected with 2.5 IU of pregnant mare serum gonadotropin (PMSG) alone and both PMSG plus 2.5 IU of chorionic gonadotropin (hCG). Apelin and APJ protein expression are modulated by estrous phases in the uterus. The uterine apelin and APJ expression are up-regulated by estrogen and down-regulated by progesterone. The expression and localization of APJ showed increased abundance in the follicles of PMSG treated mice, however, the PMSG plus HCG treatment showed formation of corpus luteum with increased abundance of APJ and progesterone secretion. The expression of apelin and APJ are regulated by pituitary gonadotropin in the ovary and uterine apelin system by ovarian steroid hormone.

Superovulatory responses using pregnant mare serum gonadotropin hormone in Murrah buffalo cows

Superovulation plays an important role in embryo transfer program. A preliminary study carried out in the Research Institute for Animal Production evaluated superovulatory responses in Murrah buffalo cows using pregnant mare serum gonadotropin (PMSG) hormone. The three buffalo cows were estrus synchronized using 5 ml prostaglandin (PGF) twice, with an interval of 11 days. PMSG was injected intra-muscularly 3000 IU on day-10 after estrus. Prostaglandins were administered 48 hours after PMSG injection. Fixed-Time artificial insemination (FTAI) was carried out at 72 hours after the last PGF treatment. Administration of hCG 2 ml/head was given at the time of FTAI. A non-surgery flushing was performed on day 6 after FTAI. Parameters observed using ultrasonography (USG) were diameter of follicle (DFL), total follicle (TFL), and number embryos (NE). Data were analyzed descriptively. The mean of DFL before PMSG treatment was 8.2 mm and after PMSG treatment was 12.5 mm. The mean of TFL before PMSG treatment was 7.7 and after PMSG treatment was 16.1. The NE obtained was one degenerative embryo. Superovulation using PMSG increased TCL and DFL. It can be concluded that the Murrah buffalo cows superovulated by PMSG showed a good response but no transferable embryo was found.

Induction of estrus using human menopausal gonadotrophin in Iraqi Awassi ewes

This study aimed to induce estrus by using Human Menopausal Gonadotrophin (HMG) in Iraqi Awassi Ewes and comparison its action with Pregnant Mare Serum Gonadotrophin (PMSG). The study was carried out between first of June 2018(non or earlier-breeding season) until all ewes lambing in the middle of November 2018. Sixty Iraqi Awassi ewes aged 2-4 years old and weight 35-45 kg were used in this study. Ewes were divided randomly into three groups, (20 ewes per each). All ewes comprised of intra-vaginal sponge impregnated by progesterone for 12 days. Control ewes (C) were injected intramuscularly with 2ml of sterile saline solution, HMG treatment group (HMG) were injected intramuscularly with 300 IU of HMG hormone while PMSG treatment Group (PMSG) were injected intramuscularly with 500 IU of PMSG at the same day of sponge removal. Estrus response percentages were 40% (8/20), 85% (17/20), 90% (18/20) in control (which significantly change P<0.05), HMG and PMSG groups, respectively. Estrus onset time was 71±1.9, 72±1.9, and 71±1.0 hours, respectively, also the data records no significant changes in estrus duration means which were 31±0.5, 31±0.7 and 31.0±0.5 hours, respectively in all groups. The pregnancy rate was 30% (6/20), 85% (17/20), 90% (18/20), respectively (control group significantly change P<0.05). The gestational period was 155± 1.4, 155±.1.3 and 155± 1.6 days respectively in all the groups and the twining rate were 1.1±0.3, 1.1±0.1 in both HMG and PMSG groups respectively without significant changes (P<0.05) while control group record no twining data. The result of this study recorded rise of dystocia and pregnancy toxemia which were higher in the PMSG group when compare with other groups. We can conclude that using HMG and PMSG hormones show a high rate of successful when they used in estrus synchronization programs but the birth problems need more investigation.

Morphological changes in mouse ovary due to hormonal hypersecretion and matrix metalloproteinase -2 activity.

We analyzed whether aberrant gonadotropin secretion affects the morphological remodeling of murine ovarian tissues facilitated by activated matrix metalloproteinase (MMP) enzymes. Six mice were intraperitoneally injected with 5 IU of pregnant mare serum gonadotropin (PMSG) or human chorionic gonadotropin (HCG) every two days after estrus synchronization. Morphology and expression of various MMPs were assessed following the successful induction of hormonal secretion in these tissues. HCG treatment, but not PMSG treatment, resulted in the expanded production of granulose second follicular cells. In addition, the number of developing follicular cells in the HCG group increased compared with that in the PMSG group. Ovarian diameters were also very small in the PMSG group. Immunohistochemistry revealed decreased MMP-2 protein activity in the HCG group and increased MMP-2 activity in the PMSG group. Activity was particularly high in theca and granulose cells of the PMSG group, but only partial activity was observed in the theca cells of the HCG group. Vascular endothelial growth factor activity was increased in both the external and internal theca cell walls in the PMSG group while the HCG group showed high overall expression of this protein in the internal theca cells. These data indicate that follicular cell activity and remodeling of the ovaries differ based on the type of secretory hormone signals they receive. Inappropriate gonadotropin secretion may induce functional changes in the ovaries, and follicular remodeling may be facilitated by the activity of various MMPs.

Performance of Pregnant Mare Serum Gonadotropin and Vitamin Mix in Inducing Striped Catfish Pangasianodon hypophthalmus Rematuration

The research aimed to assess the performance of Pregnant Mare Serum Gonadotropin (PMSG) and Human Chorionic Gonadotropin (HCG) hormone injection combined with vitamin mix to induce the rematuration of Striped catfish Pangasianodon hypophthalmus broodstock. Three PMSG and HCG treatments of 5 and 2,5 IU; 10 and 5 IU;also 20 and 10 IU/kg of broodstock body weight dosage combined with vitamin mix addition to fish feed and one control was used with four replications. The broodstock was reared for four weeks and weekly sampling for GR and SGR as well as hormone injection were performed. For the following two weeks, the broodstock was observed for maturation. Artificial spawning was conducted for broodstock reaching gonadal maturity. Statistic analysis of observed variables showed insignificant differences among the three treatments in rematuration parameters. The rematuration rate resulted in a 100% pregnancy. Broodstock treated with 10 IU PMSG and 5 IU HCG/kg of spawner body weight was able to reach maturity and spawned with the larval survival rate on the fourth day at 84,81%, thus it can be concluded that 10 IU PMSG and 5 IU HCG/kg of body weight as the best dosage.

Repeated pregnant mare serum gonadotropin-mediated oestrous synchronization alters gene expression in the ovaries and reduces reproductive performance in dairy goats.

This study aimed to elucidate the effects of repeated pregnant mare serum gonadotropin (PMSG) treatment for oestrous synchronization (ES) on ovarian gene expression and reproductive parameters in Xinong Saanen dairy goats, the dominant breed of dairy goat in China. The experiment was carried out at the Research Station of Northwest A&F University (NWAFU), China (34°16'N, 108°4'E). Forty-one does were randomly assigned to groups receiving ES treatments thrice every fortnight (3-PMSG group; n=19), or ES treatment only once simultaneously with the third ES treatment in the 3-PMSG group (1-PMSG group; n=22) during middle of the breeding season from late July (14hr light) until late September (12hr light). ES treatment was performed via intravaginal insertion of a controlled internal drug release (CIDR) device impregnated with 300mg progesterone (P4), followed by 300IU PMSG injections 48hr before CIDR withdrawal. Oestrus was monitored using vasectomized bucks. Ovaries of three goats in oestrus from both groups were harvested for morphological examination and RNA sequencing (RNA-Seq). Then, all the oestrous goats in the 1-PMSG (n=21) and 3-PMSG (n=11) groups were artificially inseminated twice. The 3-PMSG group showed reduced oestrous rate (57.89%), pregnancy rate (31.58%) and litter size (1.17) compared, respectively, with 95.45%, 68.18% and 1.67 for 1-PMSG group (p<0.05). However, no differences were found in the ovarian morphology between the 1-PMSG and 3-PMSG groups (p>0.05). RNA-Seq revealed 114 differentially expressed genes (DEGs) in the ovaries of the 3-PMSG group, among which GCG, FSTL3, TET3 and AQP3 were deemed novel and promising candidate genes for regulating fertility. The present study indicates that the three-time PMSG treatment dysregulated several ovarian genes, thereby reducing reproductive performance.

Progesterone and pregnant mare serum gonadotropin improve the reproductive capacity of long-term non-oestrus replacement gilts

Context It is a common problem that replacement gilts exhibit delayed oestrus and non-oestrus in pig production. Aims This study explored the use of progesterone and pregnant mare serum gonadotropin (PMSG) to promote oestrus and to restore the reproductive capacity of sows. Methods A total of 90 long-term non-oestrus replacement gilts were randomly divided into three groups. Group A consisted of 30 sows that were normally fed for 20 days, followed by injections of 1000 IU of PMSG on the morning of the 21st day and 100 μg of gonadotropin-releasing hormone on the 24th day. Group B consisted of 30 sows that were continuously fed with altrenogest (20 mg/head.day) for 18 days, followed by injections of 1000 IU of PMSG on the morning of the 21st day and 100 μg of gonadotropin-releasing hormone on the 24th day. Group C (control group) consisted of 30 sows that were normally fed for 20 days, followed by injections of 3 mL of physiological saline on the morning of the 21st day and 3 mL of saline on the 24th day. Oestrus identification was performed in all three groups, and sows underwent artificial insemination after the injection of gonadotropin-releasing hormone or saline. Key results We found that the follicles of long-term non-oestrus replacement gilts were not developed, and follicle diameters were &amp;lt;4 mm. The oestrus rate and pregnancy rate of the sows in Group B were significantly lower than those in Group A (30% vs 66.7% and 66.7% vs 90%) respectively. There was no difference in the litter size between Group A and Group B (11.2 vs 11.5). The sows in Group C exhibited no oestrus and no pregnancy. After treatment with progesterone and PMSG, the follicle diameters of sows in oestrus were significantly greater than those of sows in non-oestrus, and the levels of oestradiol, luteinising hormone and follicle-stimulating hormone were significantly higher than those of sows in non-oestrus. Conclusions This study showed that progesterone and PMSG treatment can alter the reproductive hormone levels and follicle diameters in long-term non-oestrus replacement gilts, promote oestrus and restore reproductive capacity in sows. Implications This study provides a method for the use of hormone-treated gilts to maximise the reproductive potential of gilts.

Effects of subcutaneous melatonin implants and short-term intravaginal progestagen treatments on estrus induction and fertility of Kivircik ewes on seasonal anestrus.

The aim of this study was to compare the efficacy of estrus induction and fertility by using subcutaneous melatonin (MEL, T1) and short-term intravaginal medroxyprogesteronacetate plus pregnant mare serum gonadotropin treatments (sMAP+eCG, T2) in ewes on seasonaly anestrus. In this study, 105 mature clinically healthy Kivircik ewes in anestrus season and 4 rams were used. After synchronization applications, ewes exhibiting estrus signs were hand-mated with rams known to be fertile. Blood samples were collected at different times in order to determine progesterone (P4) concentrations. Results showed that estrus manipulation protocols induced significant improvement in pregnancy rate. All the fertility results obtained with the sMAP+eCG or MEL groups were similar, in seasonal anestrus. The efficacy duration of P4 in the MEL group was longer than that in short-term progestagen group. Plasma P4 concentrations was significantly different between the first (I) and last (III) measurement days (p0.01). Increase in P4 concentration in T2 group was faster than that in T1 group, and blood P4 concentrations at higher levels could successfully be achieved by using any of the protocols in this study during the seasonal anestrus. In conclusion, according to the results obtained, the hormone application groups received very high estrus response. In addition, the twin ratio was found to be higher in T1 group compared to those determined in the other groups (T2 and Control group). Furthermore, plasma P4 concentrations and high birth rates were obtained in ewes in T1 and T2 groups. These procedures can be considered a good alternative to traditional procedures due to its flexibility under field conditions.

Maturasi Gonad Bawal Bintang (Trachinotus blochii) dengan Induksi Hormon Human Chorionic Gonadotropin (hCG) dan Pregnant Mare Serum Gonadotropin (PMSG)

Human Chorionic Gonadotropin (hCG) and Pregnant Mare Serum Gonadotropin (PMSG) hormone is a product that contains the hormone Folicle Stimulating Hormone (FSH) and Litiunizing hormone (LH) that play a role in regulating the development gonad process of fish. This research determine to effect hCG and PMSG hormone induction and find out the best treatment in the induction on gonad maturation of Silver pompano fish. This research used three treatments: control (NaCl), hormone hCG 20 IU.kg-1 and PMSG 20 IU.kg-1 fish body weight. Containers used in the maintenance of fish in the form of Floating Net Cage (KJA) with size 3x3x3 m. The best research result is 20 IU PMSG treatment with GSI value equal to 0.6%, HSI equal to 1.25%, maturity level of gonad reaches TKG III and histologically progress reach secondary oocyte and primary oocyte. The conclusion of this research is hCG and PMSG hormone induction effect on gonad maturation Silver pompano fish for 4 weeks compared to control treatment. The best hormone treatment is PMSG hormone treatment with a dose of 20 IU. Kg-1 fish body weight.

Impacts of GnRH, PMSG and HCG Treatments on Follicular Diameter, Conception and Lambing Rates of Egyptian Ewe Lambs Using Intravaginal Sponges

ABSTRACTThe influence of gonadotropin releasing hormone (GnRH), Pregnant Mare SerumGonadotropin (PMSG) and human Chronic Gonadotropin (hCG) on some reproductive responses ofEgyptian ewe lambs was evaluated. Twenty five animals (aged 8 – 12 months and weighed 27 - 33Kg) were divided into 5 groups ( 5 ewe lambs each). Group (1) served as a control, Group (2),received vaginal sponges impregnated with MAP (60 mg medroxy progesterone acetate) for 14 days,during this period, animals fed 3 kg Berseem, (Trifolium alexandrinum) plus 500 gm concentrate /head/ day. Group (3), received vaginal sponges impregnated with (60 mg, MAP) for 14 days, on theday of sponge removal; each animal injected by PMSG (250 IU, I/M). Group (4) animals received1.25 ml Receptal (0.5 μg, GnRH) I/M, on day 0, seven days later, ewe lambs injected with 0.5 mlEstromate (125 μg. PGF2α) I/M, after 48 hours, animals treated with a second dose of GnRH. Group(5) received two injections of (0.5 ml Estromate) at days 0 and 7, respectively, after 72 hours from thesecond dose of PGF2α ewe lambs were injected 0.2 ml hCG. Heat detection was performed and transrectalultrasound scanning also performed to confirm estrus, pregnancy and follicular diameter. Theresults revealed that, administration of PMSG (group 3) reduced the interval to estrus (the onset ofheat /hours) significantly (P< 0.01) compared with control and other groups. Regarding conceptionand lambing rates, groups 2, 3, & 4 had affected significantly (P˂ 0.01) compared to groups 1 & 5.Follicular diameter (mm) tended to increase significantly in treated groups than the control one.Results suggest that, tested hormones have effect on selected reproductive responses of Egyptian ewelambs while administration of PMSG (Group 3) has the best response compared to other hormonaltreatments.

Electroacupuncture decreases the progression of ovarian hyperstimulation syndrome in a rat model

This study aimed to elucidate the effect of electroacupuncture treatment on preventing early ovarian hyperstimulation syndrome (OHSS) and the potential mechanisms involved using an induced rat model. The ovarian response was examined by measuring ovary weight, vascular permeability, levels of inflammation (interleukin-6), tumour necrosis factor alpha, chemokine ligand 2 (also known as monocyte chemoactic protein 1), vascular endothelial growth factor and hormone concentrations (oestradiol, progesterone, testosterone and prolactin). Sprague–Dawley female rats underwent ovarian stimulation to induce OHSS. Hyperstimulated rats received consecutive electroacupuncture treatment from 3 days before the beginning of pregnant mare serum gonadotrophin treatment or the time point of pregnant mare serum gonadotrophin treatment respectively, and last until 3 days after HCG administration. Electroacupuncture treatment reduced ovary weight and vascular permeability in hyperstimulated rats. Electroacupuncture treatment also reduced the levels of serum steroid hormones (progesterone and testosterone), inflammatory cytokines (interleukin-6, tumour necrosis factor alpha and monocyte chemotactic protein 1 and vascular endothelial growth factor in hyperstimulated rats. The results indicate that electroacupuncture can modulate endocrine hormone secretion and affect the secretion of inflammatory cytokines and vascular endothelial growth factor, and thus prevent the progress of OHSS. Electroacupuncture may provide a simple and effective method for the prevention and treatment of OHSS.

Mouse Ovarian Very Small Embryonic-Like Stem Cells Resist Chemotherapy and Retain Ability to Initiate Oocyte-Specific Differentiation.

This study was undertaken to investigate stem cells in adult mouse ovary, the effect of chemotherapy on them and their potential to differentiate into germ cells. Very small embryonic-like stem cells (VSELs) that were SCA-1+/Lin-/CD45-, positive for nuclear octamer-binding transforming factor 4 (OCT-4), Nanog, and cell surface stage-specific embryonic antigen 1, were identified in adult mouse ovary. Chemotherapy resulted in complete loss of follicular reserve and cytoplasmic OCT-4 positive progenitors (ovarian germ stem cells) but VSELs survived. In ovarian surface epithelial (OSE) cell cultures from chemoablated ovary, proliferating germ cell clusters and mouse vasa homolog/growth differentiation factor 9-positive oocyte-like structure were observed by day 6, probably arising as a result of differentiation of the surviving VSELs. Follicle-stimulating hormone (FSH) exerted a direct stimulatory action on the OSE and induced stem cells proliferation and differentiation into premeiotic germ cell clusters during intact chemoablated ovaries culture. The FSH analog pregnant mare serum gonadotropin treatment to chemoablated mice increased the percentage of surviving VSELs in ovary. The results of this study provide evidence for the presence of potential VSELs in mouse ovaries and show that they survive chemotherapy, are modulated by FSH, and retain the ability to undergo oocyte-specific differentiation. These results show relevance to women who undergo premature ovarian failure because of oncotherapy.

Expression and regulation of the tumor suppressor, SEF, during folliculogenesis in humans and mice.

Similar expression to FGF (Sef or IL17-RD), is a tumor suppressor and an inhibitor of growth factors as well as of pro-inflammatory cytokine signaling. In this study, we examined the regulation of Sef expression by gonadotropins during ovarian folliculogenesis. In sexually immature mice, in situ hybridization (ISH) localized Sef gene expression to early developing oocytes and granulosa cells (GC) but not to theca cells. Sef was also expressed in mouse ovarian endothelial cells, in the fallopian tube epithelium as well as in adipose tissue venules. SEF protein expression, determined by immunohistochemistry (IHC), correlated well with Sef mRNA expression in GC, while differential expression was noticed in oocytes. High Sef mRNA but undetectable SEF protein levels were observed in the oocytes of primary/secondary follicles, while an inverse correlation was found in the oocytes of preantral and small antral follicles. Sef mRNA expression dropped after pregnant mare's serum gonadotropin (PMSG) administration, peaked at 6-8 h after human chorionic gonadotropin (hCG) treatment, and declined by 12 h after this treatment. ISH and IHC localized the changes to oocytes and mural GC following PMSG treatment, whereas Sef expression increased in mural GC and declined in granulosa-lutein cells upon hCG treatment. The ovarian expression of SEF was confirmed using human samples. ISH localized SEF transcripts to human GC of antral follicles but not to corpora lutea. Furthermore, SEF mRNA was detected in human GC recovered from preovulatory follicles. These results are the first to demonstrate SEF expression in a healthy ovary during folliculogenesis. Hormonal regulation of its expression suggests that SEF may be an important factor involved in intra-ovarian control mechanisms.

Transactivation of MicroRNA-320 by MicroRNA-383 Regulates Granulosa Cell Functions by Targeting E2F1 and SF-1 Proteins

Our previous studies have shown that microRNA-320 (miR-320) is one of the most down-regulated microRNAs (miRNA) in mouse ovarian granulosa cells (GCs) after TGF-β1 treatment. However, the underlying mechanisms of miR-320 involved in GC function during follicular development remain unknown. In this study, we found that pregnant mare serum gonadotropin treatment resulted in the suppression of miR-320 expression in a time-dependent manner. miR-320 was mainly expressed in GCs and oocytes of mouse ovarian follicles in follicular development. Overexpression of miR-320 inhibited estradiol synthesis and proliferation of GCs through targeting E2F1 and SF-1. E2F1/SF-1 mediated miR-320-induced suppression of GC proliferation and of GC steroidogenesis. FSH down-regulated the expression of miR-320 and regulated the function of miR-320 in mouse GCs. miR-383 promoted the expression of miR-320 and enhanced miR-320-mediated suppression of GC proliferation. Injection of miR-320 into the ovaries of mice partially promoted the production of testosterone and progesterone but inhibited estradiol release in vivo. Moreover, the expression of miR-320 and miR-383 was up-regulated in the follicular fluid of polycystic ovarian syndrome patients, although the expression of E2F1 and SF-1 was down-regulated in GCs. These data demonstrated that miR-320 regulates the proliferation and steroid production by targeting E2F1 and SF-1 in the follicular development. Understanding the regulation of miRNA biogenesis and function in the follicular development will potentiate the usefulness of miRNA in the treatment of reproduction and some steroid-related disorders.

In vitro fertility rate of 129 strain is improved by buserelin (gonadotropin-releasing hormone) administration prior to superovulation

The 129 mice are well recognized for their low fertility and it is speculated that this lack of fertility may be due to the oocyte condition. In this study we investigated superovulation regimens for the 129S1/SvImJ mouse strain to improve the oocyte quality and fertility rate of in vitro fertilization (IVF). Female mice were divided into four groups based on hormone and timing of injection. Group 1 received pregnant mare serum gonadotropin (PMSG) and 48 h later human chorionic gonadotropin (hCG); using the same dose, group 2 received hCG 52 h post-PMSG and group 3, 55 h post-PMSG. Group 4 received buserelin (gonadotropin-releasing hormone agonist [GnRH]) followed 24 h later by PMSG and then hCG 55 h post-PMSG. IVF was performed using 129S1/SvImJ oocytes and sperm; C57BL/6J sperm with 129S1/SvImJ oocytes was used as fertility control. The IVF fertility rate was 1% (Groups 1 and 2), 17% (Group 3) and 55% (Group 4) for 129 oocytes fertilized with 129 sperm. For 129 oocytes fertilized with C57BL/6J sperm, the fertility rate was 5% (Group 1), 10% (Group 2), 40% (Group 3) and 59% (Group 4). These results suggest that extending the interval time between PMSG and hCG and giving GnRH in addition to the standard PMSG and hCG treatments can improve IVF fertility rate of 129S1/SvImJ mouse strains significantly.

Gonadotropin treatment augments postnatal oogenesis and primordial follicle assembly in adult mouse ovaries?

BackgroundFollicle stimulating hormone (FSH) exerts action on both germline and somatic compartment in both ovary and testis although FSH receptors (FSHR) are localized only on the somatic cells namely granulosa cells of growing follicles and Sertoli cells in the seminiferous tubules. High levels of FSH in females are associated with poor ovarian reserve, ovarian hyper stimulation syndrome etc. and at the same time FSH acts as a survival factor during in vitro organotypic culture of ovarian cortical strips. Thus a further understanding of FSH action on the ovary is essential. We have earlier reported presence of pluripotent very small embryonic-like stem cells (VSELs express Oct-4A in addition to other pluripotent markers) and their immediate descendants ‘progenitors’ ovarian germ stem cells (OGSCs express Oct-4B in addition to other germ cell markers) in ovarian surface epithelium (OSE) in various mammalian species including mice, rabbit, monkey, sheep and human. Present study was undertaken to investigate the effect of pregnant mare serum gonadotropin (PMSG) on adult mice ovaries with a focus on VSELs, OGSCs, postnatal oogenesis and primordial follicle assembly.MethodsOvaries were collected from adult mice during different stages of estrus cycle and after 2 and 7 days of PMSG (5 IU) treatment to study histo-architecture and expression for FSHR, pluripotent stem cells , meiosis and germ cell specific markers.ResultsPMSG treatment resulted in increased FSHR and proliferation as indicated by increased FSHR and PCNA immunostaining in OSE and oocytes of primordial follicles (PF) besides the granulosa cells of large antral follicles. Small 1–2 regions of multilayered OSE invariably associated with a cohort of PF during estrus stage in control ovary were increased to 5–8 regions after PMSG treatment. This was associated with an increase in pluripotent transcripts (Oct-4A, Nanog), meiosis (Scp-3) and germ cells (Oct-4B, Mvh) specific markers. MVH showed positive immuno staining on germ cell nest-like clusters and at places primordial follicles appeared connected through oocytes.ConclusionsThe results of the present study show that gonadotropin (PMSG) treatment to adult mouse leads to increased pluripotent stem cell activity in the ovaries, associated with increased meiosis, appearance of several cohorts of PF and their assembly in close proximity of OSE. This was found associated with the presence of germ cell nests and cytoplasmic continuity of oocytes in PF. We have earlier reported that pluripotent ovarian stem cells in the adult mammalian ovary are the VSELs which give rise to slightly differentiated OGSCs. Thus we propose that gonadotropin through its action on pluripotent VSELs augments neo-oogenesis and PF assembly in adult mouse ovaries.

Reproductive performance in out-of-breeding season of fatty ewes using implant norgestomet with or without PMSG

Pregnancy in out-of-breeding season in ewes increases the economical goals. Synchronization of estrus and ovulation is essential for above program. The aims of this study using implant norgestomet with or without Pregnant Mare Serum Gonadotropin (PMSG) were to evaluate the serum progesterone (P4) concentration changes: the conception rate and estimation of the lambing rate and litter size. In total, 80 non-cycling multiparous Iranian Kurdish breed fat-tailed ewes with <0/5 ng/ml P4 were used in April and May 2008 in the suburb of Mashhad, Iran. The animals were randomly divided into three groups: a control group (n = 30) without hormonal treatment, another group (n = 25) received 3 mg of norgestomet implant placed subcutaneously in the convex surface of the ear for 9 days, and the third group (n = 25) treated with 3 mg of norgestomet implant for 9 days with an IM injection of 500 IU PMSG at implant removal. The progesterone of treatment and control groups were measured on days 4, 9, and 13 after removal of the norgestomet using radioimmunoassay. Every five ewes were exposed to one ram after 24 h of norgestomet removal in treatment and control groups, simultaneously. The pregnancy was examined after 25 days of ram removal using ultrasonography. Progesterone concentration was significantly higher in treatment groups on 9 and 13 days after norgestomet removal (P < 0.05). The pregnancy rate in the control, non-PMSG, and PMSG treatments groups were 17%, 52%, and 72%, respectively. The rates of single and twin pregnancy in the non-PMSG treatment group were 69% and 31%, respectively. These rates in norgestomet and PMSG treatment group were 50% and 39%, respectively. Triplet pregnancy (11%) was observed only in the PMSG treatment group. It was concluded that using implant norgestomet especially accompanied with PMSG can increase and improve the fertilization rate of ewe in the out-of-breeding season program.

Effect of gonadotropin-releasing hormone (GnRH) treatment on multiple births in Afshari ewes

The purpose of this study was to investigate the effects of gonadotropin-releasing hormone (GnRH) administration on the induction of multiple births in synchronized Afshari ewes. 16 cycling, multiparous fat-tailed Iranian Afshari ewes, weighing 66.5 ± 2.5 kg, were used in the trail. Estrus was synchronized using controlled internal drug release CIDR’s; inserted for 14 days. Pregnant mare serum gonadotrophin (PMSG) (300 IU) was injected to ewes a day before CIDR removal. The ewes was randomly allocated to two groups (n = 8). Synchronization treatment was initiated with a week interval in two groups (weeks 1 and 2). 24 h following CIDR removal (day 1), GnRH (50 µg) was administered to half of each group ewes (GnRH and control groups), and ewes mated with the proven rams. Pregnancy was diagnosed with the aid of transabdominal ultrasonograpy 30 days after mating. Ovarian follicular activity was monitored with the aid of transrectal ultrasonograpy on the days of CIDR removal and at estrus (approximately day 1). Following PMSG treatment, the mean number of large follicles on total ovaries increased from CIDR removal to estrus 1.48 ± 0.71 vs. 2.85 ± 0.82 (P < 0.05). Lambing rate in GnRH group (162.5%) was higher (P < 0.05) compared to the control group (125%). The mean weights of lambs born in the GnRH and control groups were 5.5 ± 0.1 and 5.2 ± 0.1, respectively.

Effect of gonadotropin-releasing hormone (GnRH) treatment on multiple births in Afshari ewes

The purpose of this study was to investigate the effects of gonadotropin-releasing hormone (GnRH) administration on the induction of multiple births in synchronized Afshari ewes. 16 cycling, multiparous fat-tailed Iranian Afshari ewes, weighing 66.5 ± 2.5 kg, were used in the trail. Estrus was synchronized using controlled internal drug release CIDR’s; inserted for 14 days. Pregnant mare serum gonadotrophin (PMSG) (300 IU) was injected to ewes a day before CIDR removal. The ewes was randomly allocated to two groups (n = 8). Synchronization treatment was initiated with a week interval in two groups (weeks 1 and 2). 24 h following CIDR removal (day 1), GnRH (50 µg) was administered to half of each group ewes (GnRH and control groups), and ewes mated with the proven rams. Pregnancy was diagnosed with the aid of transabdominal ultrasonograpy 30 days after mating. Ovarian follicular activity was monitored with the aid of transrectal ultrasonograpy on the days of CIDR removal and at estrus (approximately day 1). Following PMSG treatment, the mean number of large follicles on total ovaries increased from CIDR removal to estrus 1.48 ± 0.71 vs. 2.85 ± 0.82 (P < 0.05). Lambing rate in GnRH group (162.5%) was higher (P < 0.05) compared to the control group (125%). The mean weights of lambs born in the GnRH and control groups were 5.5 ± 0.1 and 5.2 ± 0.1, respectively.

The conflict between hierarchical ovarian follicular development and superovulation treatment

In mammals with a low ovulation rate phenotype, ovarian follicular development is thought to be hierarchical with few, if any, antral follicles at similar stages of development. The hypothesis being tested herein was that if most follicles are in a functionally different state, then the application of exogenous hormones to increase ovulation rate will not overcome the hierarchical nature of follicular development. Using sheep as the experimental model, the functional states of all non-atretic antral follicles > or =2 mm diameter were assessed in individual ewes (N=10/group) during anoestrus with or without pregnant mare's serum gonadotrophin (PMSG) treatment, or after a standard superovulation regimen, or during the follicular phase of the oestrous cycle. The functional states of these follicles were assessed by measuring the FSH- or human chorionic gonadotrophin (hCG)-induced cAMP responses of granulosa cells in vitro. There were significant overall effects across the treatment groups on the responses of granulosa cells to either FSH or LH (both P<0.001). It was concluded that for anoestrous ewes with or without PMSG treatment, and ewes during the follicular phase, granulosa cell populations of many follicles (> or =2 mm diameter) did not share a similar cAMP response to FSH ( approximately 50% of follicles) or hCG (>90% of follicles) either on a per cell or total cell basis. After superovulation, < or =30 and 10% respectively of the granulosa cell populations shared similar responses to FSH and LH with regard to follicular diameter and cAMP output. Thus, exogenous hormone treatments used routinely for increasing oocyte yield do not effectively override the hierarchical pattern of ovarian follicular development during the follicular phase.