Follicle Recruitment Research Articles

Bone Morphogenetic Proteins are Significantly Reduced in the Follicular Fluid of Han Chinese Polycystic Ovary Syndrome Patients

Background: Polycystic ovary syndrome (PCOS) is a common endocrine disorder affecting up to 10% of women of childbearing age. Traditionally, androgen elevation has been considered the main pathological cause for PCOS. However, it is increasingly recognized that bone morphogenetic proteins (BMPs), members of the transforming growth factor β (TGF-β) family, play important roles in follicle recruitment, follicle selection, and follicle-stimulating hormone (FSH) responsiveness. Methods: Twenty-eight PCOS patients and fourteen tubular infertility patients were recruited from patients seeking reproductive assistance at The Center of Reproductive Medicine in Taiyuan, China. Each patient went through an in vitro fertilization and embryo transplantation (IVF-ET) procedure. The mRNA and protein levels of hormones, hormone receptors, and BMPs were evaluated using real-time PCR (RT-PCR) and enzyme-linked immunosorbent assay (ELISA), respectively. Results: Hormone levels were comparable in PCOS and control patients. In contrast, significant differences were observed in BMP levels in these two groups. BMP-5, -6, -7, and -8A levels were all markedly lower in follicular fluid in PCOS patients (p<0.05), with BMP-7 being the most significantly down regulated biomarker (p=0.0004). The levels of all BMPs were positively correlated with follicle-stimulating hormone receptor (FSHR). Conclusions: Expression levels of multiple BMPs were significantly down-regulated in follicular fluid from PCOS patients. Their low abundance as well as their correlation with FSHR confirmed BMPs as key regulators of PCOS pathogenesis.

Anti-Müllerian hormone regulation by the bone morphogenetic proteins in the sheep ovary: deciphering a direct regulatory pathway.

In the ovary, anti-Müllerian hormone (AMH) is produced by the granulosa cells of growing follicles and can modulate the recruitment of primordial follicles and the FSH-dependent development of follicles. However, the regulation of its production remains poorly understood. Recently, a stimulating effect of the bone morphogenetic proteins (BMPs) on AMH production by granulosa cells has been shown in vitro, but the molecular mechanisms implicated in this regulation and its physiological importance in ovarian function have not yet been established. In the hyperprolific Booroola ewes carrying the FecB(B) partial loss-of-function mutation in the fecundity gene encoding the FecB/BMP receptor, type 1B, the granulosa cells of antral follicles expressed and secreted low AMH amounts, resulting in low AMH concentrations in blood, despite high numbers of AMH-secreting follicles in ovaries. The presence of the FecB(B) mutation impaired the granulosa cell response to the stimulating action of BMP4 on AMH production, indicating a crucial role of the BMP receptor, type 1B in AMH regulation. In ovine granulosa cells, BMP4 enhanced the transcriptional activity of the human AMH promoter, and this action depended on the presence of SMAD1, acting on a promoter sequence located between -423 and -202 bp upstream of the AMH transcription start site. SMAD1 and SF1 acted in concert to mediate BMP4 action on the AMH promoter. Among the 2 SF1 binding sites present on the AMH promoter, the most proximal site, located at -92 bp upstream of the AMH transcription start site, was found to be critical for ensuring the response of the AMH promoter to BMP4. In conclusion, AMH could mediate the actions of BMPs in regulating follicular development and contributing to the determination of ovulation numbers. A molecular model of regulation of the AMH promoter transactivation by BMP signaling is proposed.

Study of Assessment of Ovarian Function by Serum AMH Estimation Evaluation

Anti mullerian hormone (AMH) is a member of the transforming growth factor family of growth and differentiation factors. In the ovary, AMH has an inhibitory effect on promidial follicle recruitment as well as on the responsiveness of growing follicles to follicle-stimulating hormone (FSH). The ovary-specific expression pattern in granlosa cells of growing non-selected follicles makes AMH an ideal marker for the quantitative aspect of ovarian reserve as well as ovarian dysfunction.

AMH and AMHR2 Polymorphisms and AMH Serum Level Can Predict Assisted Reproduction Outcomes: A Cross-Sectional Study

Background: In human assisted reproduction, the ovarian response to exogenous recombinant Follicle-stimulating Hormone (FSH) therapy is variable and difficult to predict. The standard protocol of ovarian hyperstimulation can result in satisfactory response; however, an unsatisfactory response necessitates FSH dose adjustment or results in ovarian hyperstimulation syndrome (OHSS). Polymorphisms in AMH and AMHR2 genes appear to affect hormone biological activities, thus affecting follicle recruitment and development, leading to infertility. We aimed to evaluate AMH and AMHR2 polymorphisms in infertile women, and correlate those findings with AMH, FSH and estradiol serum level response to controlled ovarian hyperstimulation (COH), as well as assisted reproduction outcomes. Methods: A cross-sectional study comprising 186 infertile women that underwent one cycle of high complexity assisted reproductive treatment. Blood samples were collected and a TaqMan assay was used for AMH G146T/rs10407022 and AMHR2 A-482G/rs2002555, A10G/rs11170555, C1749G/rs2071558 and G4952A/rs3741664 genotyping, and FSH, estradiol and AMH levels were measured. The findings were correlated to human reproduction outcomes. Results: AMH rs10407022 and AMHR2 rs2002555 polymorphisms were not associated with hormonal measurements, whereas AMHR2 rs11170555 and rs3741664 were positively associated with AMH, estradiol and FSH levels. The genotype distribution of AMH and AMHR2 genes according to Controlled Ovarian Hyperstimulation did not show a positive association. However, an association with AFC, degree of oocyte maturation (allele G of AMHR2 rs2071558) the number of embryos produced (alleles T and G of AMH rs10407022 and AMHR2 rs2002555, respectively) and frozen embryo (allele G of AMHR2 rs11170555) were found to be statistically associated. Considering COH, serum AMH and AFC were a positive predictor to OHSS. Regarding serum AMH and assisted reproduction outcomes, a positive correlation with all variables studied was found. Comparing AFC and AMH as predictors of human reproduction outcomes, the AFC was less effective than serum AMH. Considering pregnancy rates, no marker was positively associated. Conclusion: AMHR2 polymorphisms were associated with estradiol, AMH and FSH measurements, as well as number and quality of embryos, while AMH polymorphisms was associated with number of embryos produced. Serum AMH was correlated with nearly all variables analyzed in assisted reproductive treatment, demonstrating that it represents a better biomarker of OHSS and human reproduction outcomes compared to AMH and AMHR2 polymorphisms.

Spanish consensus on premature menopause

IntroductionWhile we recognise that the term premature menopause is more accepted by most non-specialist health care providers and by the general population, ‘primary ovarian insufficiency’ (POI) is currently considered the most apposite term to explain the loss of ovarian function, because it better explains the variability of the clinical picture, does not specify definitive failure, and highlights the specific ovarian source. Its pathogenesis involves a congenital reduction in the number of primordial follicles, poor follicle recruitment, or accelerated follicular apoptosis. However, its cause is unknown in most cases. AimThis guide analyses the factors associated with the diagnosis and treatment of POI and provides recommendations on the most appropriate diagnostic and therapeutic measures for women under 40 years of age who experience POI. MethodologyA panel of experts from various Spanish scientific societies related to POI (Spanish Menopause Society, Spanish Fertility Society, and Spanish Contraception Society) met to reach a consensus on these issues. ResultsHormonal therapy (HT) is considered the treatment of choice to alleviate the symptoms of hypoestrogenism and to prevent long-term consequences. We suggest that HT should be continued until at least age 51, the average age at natural menopause. The best treatment to achieve pregnancy is oocyte/embryo donation. If a patient is to undergo treatment that will reduce her fertility, she should be informed of this issue and the available techniques to preserve ovarian function, mainly vitrification of oocytes.

The postpartum period in dromedary camels: Uterine involution, ovarian activity, hormonal changes, and response to GnRH treatment

The aim of the present study was to investigate the time for complete uterine involution and resumption of ovarian activity in postpartum dromedary camels, relative to hormonal changes. A total of six females were examined by ultrasonography twice weekly starting 3d after parturition. GnRH was administered when the follicles reached ≥0.9cm diameter. Blood samples were collected for hormonal analysis. Results revealed that the mean intervals for complete involution of the previously gravid horn, non-gravid horn, and cervix were 34.33±3.9, 29.01±0.81, and 28.71±1.51d, respectively. After GnRH treatment (Days 17–34), five of the six camels had ovulated. The corpus luteum was detected by Day 4.1±1.6 after GnRH treatment and lasted for 6±1.1d. Serum progesterone (P4) was basal and increased only after GnRH treatment. Serum estradiol 17-β (E2) peaked twice: when a large follicle was detected and 8.5±2.8d post-GnRH treatment. The serum FSH pattern was biphasic, with two peaks just before the recruitment of small follicles and 4.67±4.1d after GnRH treatment. The five ovulating females were mated; two conceived after the first service and three after the second service. The interval from calving to conception was 78.16±3.71d. It was concluded that in dromedary camels, involution of the uterus is completed by the 5th week postpartum, these camels are highly responsive to early GnRH treatment, and they can be mated between the 5th and 6th week after parturition with encouraging conception rates.

Regulation of primordial follicle recruitment by cross-talk between the Notch and phosphatase and tensin homologue (PTEN)/AKT pathways.

The growth of oocytes and the development of follicles require certain pathways involved in cell proliferation and survival, such as the phosphatidylinositol 3-kinase (PI3K) pathway and the Notch signalling pathway. The aim of the present study was to investigate the interaction between Notch and the PI3K/AKT signalling pathways and their effects on primordial follicle recruitment. When the Notch pathway was inhibited by L-685,458 or N-[N-(3,5-difluorophenacetyl)-l-alanyl]-S-phenylglycinet-butyl ester (DAPT) in vitro, the expression of genes in the pathway and the percentage of oocytes in growing follicles decreased significantly in mouse ovaries. By 2 days postpartum, ovaries exposed to DAPT, short interference (si) RNA against Notch1 or siRNA against Hairy and enhancer of split-1 (Hes1) had significantly decreased expression of HES1, the target protein of the Notch signalling pathway. In contrast, expression of phosphatase and tensin homologue (Pten), a negative regulator of the AKT signalling pathway, was increased significantly. Co immunoprecipitation (Co-IP) revealed an interaction between HES1 and PTEN. In addition, inhibition of the Notch signalling pathway suppressed AKT phosphorylation and the proliferation of granulosa cells. In conclusion, the recruitment of primordial follicles was affected by the proliferation of granulosa cells and regulation of the interaction between the Notch and PI3K/AKT signalling pathways.

A single nucleotide polymorphism of bone morphogenic protein-15 is not associated with ovarian reserve or response to ovarian stimulation.

Is there any effect of the -9C>G variant in the bone morphogenic protein-15 (BMP15) gene on ovarian response and/or current markers of ovarian reserve in patients undergoing in vitro fertilization (IVF) treatment? No significant associations of BMP15 genotypes with ovarian response (number of oocytes retrieved) and/or markers of ovarian reserve were detected in our cohort of women undergoing IVF treatment. There is evidence that genetic variation influences patients' response to ovarian stimulation therapy. BMP15 plays a role in the recruitment of primordial follicles. Therefore, variation in BMP15 could predict ovarian reserve and response to ovarian stimulation. Two previous studies have determined a significant correlation between the BMP15 -9C>G variant and over-response to ovarian stimulation. No studies to date have correlated this variant with ovarian reserve markers. In this prospective observational study, we genotyped the BMP15 -9C>G single nucleotide polymorphism in 239 unrelated women undergoing their first cycle of controlled ovarian stimulation for IVF and ICSI (intra-cytoplasmic sperm injection) using gonadotrophins at a tertiary referral centre for reproductive medicine between March 2009 and August 2010. Baseline pelvic ultrasound and blood tests were taken on Days 2-3 of the cycle for assessment of baseline hormones and for DNA extraction. Genotypes were determined using TaqMan allelic discrimination assay. Regression analysis was performed to assess the effect of the BMP15 genotype on the ovarian reserve markers, serum anti-Müllerian hormone (s-AMH), follicle stimulating hormone (s-FSH) and antral follicle count (AFC), with adjustment for age and body mass index (BMI), and on the primary outcomes of response (number of oocytes retrieved and gonadotrophin dose) with adjustment for age, BMI and treatment received. There was no evidence of any statistically significant (P < 0.05) difference in basal s-FSH, s-AMH and AFC between individuals with different BMP15 genotypes. The number of oocytes retrieved and gonadotrophin dose used were also comparable between the individuals with different genotypes. A larger sample size would be required in order to determine if the BMP15 genotype has a small effect on ovarian reserve or response. When considering the development of integrative clinical algorithms for individual FSH doses, our analysis suggests that the genotyping of BMP15 -9C>G does not provide additional useful information as a predictor of ovarian reserve or response to ovarian stimulation. The study was funded by the Manchester Biomedical Research Centre. The authors have no competing interests to declare.

How the FMR1 gene became relevant to female fertility and reproductive medicine.

This manuscript describes the 6 year evolution of our center’s research into ovarian functions of the FMR1 gene, which led to the identification of a new normal CGGn range of 26–34. This “new” normal range, in turn, led to definitions of different alleles (haplotypes) based on whether no, one or both alleles are within range. Specific alleles then were demonstrated to represent distinct ovarian aging patterns, suggesting an important FMR1 function in follicle recruitment and ovarian depletion of follicles. So called low alleles, characterized by CGGn<26, appear associated with most significant negative effects on reproductive success. Those include occult primary ovarian insufficiency (OPOI), characterized by prematurely elevated follicle stimulating hormone (FSH) and prematurely low anti-Müllerian hormone, and significantly reduced clinical pregnancy rates in association with in vitro fertilization (IVF) in comparison to women with normal (norm) and high (CGGn>34) alleles. Because low FMR1 alleles present in approximately 25% of all females, FMR1 testing at young ages may offer an opportunity for earlier diagnosis of OPOI than current practice allows. Earlier diagnosis of OPOI, in turn, would give young women the options of reassessing their reproductive schedules and/or pursue fertility preservation via oocyte cryopreservation when most effective.

Ovarian transplantation and mechanism for resting follicle recruitment

To study the effectiveness of frozen ovarian cortex transplants compared to fresh transplants, to preserve fertility in patients with cancer or anticipated ovarian failure, and to explain “resting follicle” recruitment in women as they age. Ovary freezing and transplantation has garnered increasing interest as a possible way to preserve fertility for cancer patients and even for the natural decline in fertility with aging.

Discontinuation of long term use of hormonal contraceptives leads to a significant increase in AFC and oocyte yield in women undergoing elective fertility preservation or donor cycles

Antral follicle count (AFC) is used by clinicians to counsel their patients about their ovarian reserve and approximates the oocyte yield after ovarian stimulation. Hormonal contraceptives suppress the hypothalamic–pituitary–ovarian axis and may potentially influence follicle recruitment and response to controlled ovarian stimulation (COS). In this study, we aimed to determine whether stopping hormonal contraception for at least two months improves AFC and egg yield in women undergoing elective fertility preservation or donor cycles.

The regulation and assessment of follicular growth

Folliculogenesis is the process by which waves of small primordial follicles possessing immature oocytes are recruited to undergo development into large antral follicles, with one then being selected for ovulation of a fully competent oocyte. Folliculogenesis can be divided into three stages: follicle recruitment, selection and ovulation, and has two phases: the initial gonadotrophin-independent phase and the later gonadotrophin-dependent phase. It involves an elaborate array of biochemical signalling factors, both stimulatory and inhibitory, and the regulation of follicle growth relies on these being tightly controlled. Their increasing understanding allows reproductive biologists to attempt manipulation of folliculogenesis, which can be useful in clinical areas such as assisted reproduction and contraception. The rising average age of childbearing in many developed countries is bringing an additional focus on the importance of assessing a woman's non-growing follicular pool; i.e. her ovarian reserve. This review examines the important regulatory players in the different stages of folliculogenesis and describes some of the currently available measures of ovarian reserve.

Transgenerational inheritance of ovarian development deficiency induced by maternal diethylhexyl phthalate exposure.

Diethylhexyl phthalate (DEHP) is a widely used industrial additive for increasing plastic flexibility. It disrupts the physiological functions of endogenous hormones and induces abnormal development of mammals. The objectives of the present study were to evaluate the effects of DEHP exposure on ovarian development of pregnant mice and whether the effects are inheritable. We found that the synthesis of oestradiol in pregnant mice after DEHP exposure was significantly decreased, and that the first meiotic progression of female fetal germ cells was delayed. Furthermore, the DNA methylation level of Stra8 was increased and the expression levels of Stra8 were significantly decreased. An accelerated rate of follicle recruitment in F1 mice was responsible for the depletion of the primordial-follicle pool. Maternal DEHP exposure also significantly accelerated the recruitment of primordial follicles in F2 mice. In conclusion, our results indicated that maternal DEHP exposure induced ovarian development deficiency, which was transgenerational in mice.

Fibrin-mediated delivery of an ovarian follicle pool in a mouse model of infertility.

The cryopreservation and autotransplantation of ovarian tissue is emerging as a powerful approach for preserving fertility. However, for cancer patients, it may not be possible to transplant ovarian tissue due to the risk of re-seeding disease. We investigated strategies for transplantation of individually isolated follicles to minimize the risk of re-introducing cancer cells present within the vasculature of ovarian stroma. Procedures for large-scale isolation of early-stage follicles and their encapsulation into fibrin hydrogels were developed. For in vivo validation studies, mice were ovariectomized and transplanted with encapsulated follicles into the ovarian bursa. A substantial increase in the number of secondary follicles was observed in the graft at 9 days after transplantation, and antral follicles by day 21, demonstrating primordial follicle recruitment into the growing pool. Initially, elevated follicle-stimulating hormone levels declined substantially by day 21, indicating feedback from the graft; presence of corpora lutea showed the graft's capability of restoring hormone cyclicity. Taken together, the transplanted follicles were able to engraft, mature, and restore ovarian function in an infertile mouse. This biomaterial may, thus, provide a platform for follicle transplantation with a low risk of cancer contamination and for developing strategies that preserve fertility for women facing a cancer diagnosis.

Maternal sympathetic stress impairs follicular development and puberty of the offspring.

Chronic cold stress applied to adult rats activates ovarian sympathetic innervation and develops polycystic ovary (PCO) phenotype. The PCO syndrome in humans originates during early development and is expressed before or during puberty, which suggests that the condition derived from in utero exposure to neural- or metabolic-derived insults. We studied the effects of maternal sympathetic stress on the ovarian follicular development and on the onset of puberty of female offspring. Timed pregnant rats were exposed to chronic cold stress (4 °C, 3 h/daily from 1000 to 1300 h) during the entire pregnancy. Neonatal rats exposed to sympathetic stress during gestation had a lower number of primary, primordial, and secondary follicles in the ovary and a lower recruitment of primary and secondary follicles derived from the primordial follicular pool. The expression of the FSH receptor and response of the neonatal ovary to FSH were reduced. A decrease in nerve growth factor (NGF) mRNA was found without change in the low-affinity NGF receptor. The FSH-induced development of secondary follicles was decreased. At puberty, estradiol plasma levels decreased without changes in LH plasma levels. Puberty onset (as shown by the vaginal opening) was delayed. Ovarian norepinephrine (NE) was reduced; there was no change in its metabolite, 3-methoxy-4-hydroxyphenylglycol, in stressed rats and no change in NE turnover. The changes in ovarian NE in prepubertal rats stressed during gestation could represent a lower development of sympathetic nerves as a compensatory response to the chronically increased NE levels during gestation and hence participate in delaying reproductive performance in the rat.

Daily exposure to Di(2-ethylhexyl) phthalate alters estrous cyclicity and accelerates primordial follicle recruitment potentially via dysregulation of the phosphatidylinositol 3-kinase signaling pathway in adult mice.

Humans are exposed daily to di(2-ethylhexyl) phthalate (DEHP), a plasticizer found in many consumer, medical, and building products containing polyvinyl chloride. Large doses of DEHP disrupt normal ovarian function; however, the effects of DEHP at environmentally relevant levels, the effects of DEHP on folliculogenesis, and the mechanisms by which DEHP disrupts ovarian function are unclear. The present study tested the hypothesis that relatively low levels of DEHP disrupt estrous cyclicity as well as accelerate primordial follicle recruitment by dysregulating phosphatidylinositol 3-kinase (PI3K) signaling. Adult CD-1 mice were orally dosed with DEHP (20 μg/kg/day-750 mg/kg/day) daily for 10 and 30 days. Following dosing, the effects on estrous cyclicity were examined, and follicle numbers were histologically quantified. Further, the ovarian mRNA and protein levels of PI3K signaling factors that are associated with early folliculogenesis were quantified. The data indicate that 10- and 30-day exposure to DEHP prolonged the duration of estrus and accelerated primordial follicle recruitment. Specifically, DEHP exposure decreased the percentage of primordial follicles and increased the percentage of primary follicles counted following 10-day exposure and increased the percentage of primary follicles counted following 30-day exposure. DEHP exposure, at doses that accelerate folliculogenesis, increased the levels of 3-phosphoinositide-dependent protein kinase-1, mammalian target of rapamycin complex 1, and protein kinase B and decreased the levels of phosphatase and tensin homolog, potentially driving PI3K signaling. Collectively, relatively low levels of DEHP disrupt estrous cyclicity and accelerate primordial follicle recruitment potentially via a mechanism involving dysregulation of PI3K signaling.

Identification and characterization of microRNAs in the ovaries of multiple and uniparous goats (Capra hircus) during follicular phase

BackgroundSuperior kidding rate is an important economic trait in production of meat goat, and ovulation rate is the precondition of kidding rate. MicroRNAs (miRNAs) play critical roles in almost all ovarian biological processes, including folliculogenesis, follicle development, follicle atresia, luteal development and regression. To find out the different ovarian activity and follicle recruitment with miRNA-mediated posttranscriptional regulation, the small RNAs expressed pattern in the ovarian tissues of multiple and uniparous Anhui White goats during follicular phase was analyzed using Solexa sequencing data.Results1008 miRNAs co-expressed, 309 and 433 miRNAs specifically expressed in the ovaries of multiple and uniparous goats during follicular phase were identified. The 10 most highly expressed miRNAs in the multiple library were also the highest expressed in the uniparous library, and there were no significantly different between each other. The highest specific expressed miRNA in the multiple library was miR-29c, and the one in the uniparous library was miR-6406. 35 novel miRNAs were predicted in total. GO annotation and KEGG Pathway analyses were implemented on target genes of all miRNA in two libraries. RT-PCR was applied to detect the expression level of 5 randomly selected miRNAs in multiple and uniparous hircine ovaries, and the results were consistent with the Solexa sequencing data.ConclusionsIn the present study, the different expression of miRNAs in the ovaries of multiple and uniparous goats during follicular phase were characterized and investigated using deep sequencing technology. The result will help to further understand the role of miRNAs in kidding rate regulation and also may help to identify miRNAs which could be potentially used to increase hircine ovulation rate and kidding rate in the future.Electronic supplementary materialThe online version of this article (doi:10.1186/1471-2164-15-339) contains supplementary material, which is available to authorized users.

Administration of DHEA augments progesterone production in a woman with low ovarian reserve being transplanted with cryopreserved ovarian tissue

In recent years cryopreservation of ovarian tissue prior to potentially gonadotoxic treatment for malignant disease has proved to be an option for preservation of the reproductive function including fertility [1]. Following successful cancer treatment women have chosen to have transplantation of their frozen-thawed tissue if ovarian failure occurred as a consequence of cancer treatment. The autotransplanted tissue has in various centers resulted in the re-establishment of ovarian function leading to the return of fertility and the birth of healthy children [2, 3]. However, the ovarian reserve in the transplanted tissue typically is very low as currently only a limited number of follicles survive the entire procedure including freezing, thawing and transplantation [4]. This diminished reserve is reflected by persistent low levels of AMH [4], limiting the efficacy of controlled ovarian stimulation (COS) with exogenous FSH. In terms of fertility treatment, the women who have had frozen/thawed ovarian tissue transplanted often resemble poor responder patients and patients of advanced reproductive age. Attempts to augment the number of developing follicles by administration of oral DHEA for some months in the latter category of women have been reported [5–7], there being a growing literature describing a higher oocyte yield following COS and oocytes showing a better quality and thereby improving the reproductive outcome [5–7]. The particular mechanism by which DHEA may enhance follicle survival and growth has not yet been fully elucidated, but conversion of DHEA to androgens and an androgen priming effect on early stages of follicular development leading to an increased FSH receptor expression is one possible mechanism [8]. Although the vast majority of DHEA in the body is produced by the adrenals one obstacle in defining a more precise function of DHEA in improving follicle recruitment is the fact that the circulating DHEA is the sum of the local productions in the ovaries and those of adrenal glands [9]. In this study we observed the ovarian and endocrine events following DHEA administration in a woman, who had normal adrenal function but with very low ovarian reserve consequent to transplantation of frozen/thawed ovarian tissue, being postmenopausal at the time of transplantation. Only a fraction of frozen/thawed tissue from one ovary had been grafted with subsequent low ovarian reserve and evidenced by few follicles. This situation allowed a more direct evaluation of the endocrinological effect of DHEA administration on the synthesis of sex steroids.

Enhanced follicular recruitment and atresia in cortex derived from ovaries with endometriomas

To evaluate the effects of endometriomas on the regulation of early follicular development. Histologic analysis of prospectively collected biopsy samples. Research unit in a university hospital. Women <40 years of age who have ovarian endometriomas. Biopsy of healthy cortex from ovaries affected by endometriomas (≤ 4 cm) and contralateral ovaries without cysts. Histomorphological staging of early follicles, measurement of follicle, oocyte, and oocyte nucleus diameters, immunohistochemistry of proliferating cell nuclear antigen, and caspase-3. Thirteen cortical samples from ovaries with endometriomas and 13 samples from contralateral ovaries without endometriomas were evaluated. Cortex from ovaries with endometriomas contained significantly more morphologically atretic early follicles than cortex from contralateral ovaries without cysts. These follicles showed cleaved caspase-3 immunostaining. Diameters of primordial follicles and oocytes were decreased in cortex from ovaries with endometriomas, whereas early follicles with proliferating cell nuclear antigen-positive granulosa cells (GCs) were significantly increased in number. Ovaries with endometriomas, which may be more prone to local pelvic inflammation, showed activated follicular recruitment and atresia of early follicles. The potential contribution of inflammation to follicle "burnout" in case of endometriomas is discussed.

Use of Equine Chorionic Gonadotropin to Control Reproduction of the Dairy Cow: A Review

Equine chorionic gonadotropin (eCG) is a member of the glycoprotein family of hormones along with LH, FSH and thyroid-stimulating hormone. In non-equid species, eCG shows high LH- and FSH-like activities and has a high affinity for both FSH and LH receptors in the ovaries. On the granulosa and thecal cells of the follicle, eCG has long-lasting LH- and FSH-like effects that stimulate oestradiol and progesterone secretion. Thus, eCG administration in dairy cattle results in fewer atretic follicles, the recruitment of more small follicles showing an elevated growth rate, the sustained growth of medium and large follicles and improved development of the dominant and pre-ovulatory follicle. In consequence, the quality of the ensuing CL is improved, and thereby progesterone secretion increased. Based on these characteristics, eCG treatment is utilized in veterinary medicine to control the reproductive activity of the cow by i) improving reproductive performance during early post-partum stages; ii) increasing ovulation and pregnancy rates in non-cyclic cows; iii) improving the conception rate in cows showing delayed ovulation; and finally, iv) eCG is currently included in protocols for fixed-time artificial insemination since after inducing the synchrony of ovulation using a progesterone-releasing device, eCG has beneficial effects on embryo development and survival. The above effects are not always observed in cyclic animals, but they are evident in animals in which LH secretion and ovarian activity are reduced or compromised, for instance, during the early post-partum period, under seasonal heat stress, in anoestrus animals or in animals with a low body condition score.