Effects of growth hormone on follicle growth, oocyte maturation, and ovarian steroidogenesis

Identification and analysis of key circRNAs in the mouse embryonic ovary provides insight into primordial follicle development

BACKGROUND

CircRNAs are a class of noncoding RNAs with tissue- and development-specific expression characteristics. In many mammals, primordial follicle development begins in the embryonic stage. However, the study of circRNAs in primordial follicle development in mice has not been reported.

RESULTS

In this study, ovaries were collected from mouse foetuses at 15.5 days post coitus (dpc) and 17.5 dpc, which are two key stages of primordial follicle development. A total of 4785 circRNAs were obtained by using RNA-seq. Of these, 83 differentially expressed circRNAs were identified. Gene Ontology (GO) and Kyoto Encyclopedia of Genes and Genomes (KEGG) enrichment analyses showed that these differential circRNAs were mainly involved in the regulation of reproductive development. Through qRT-PCR, back-splice sequence detection and enzyme digestion protection experiments, we found that circ-009346, circ-014674, circ-017054 and circ-008296 were indeed circular. Furthermore, circ-009346, circ-014674 and circ-017054 were identified as three key circRNAs by analysing their expression in the ovaries of mice at different developmental stages. The circRNA-miRNA-mRNA interaction network was constructed and validated for target miRNA and mRNA using qRT-PCR. The interacting genes circ-009346, circ-014674, and circ-017054 were subjected to KEGG enrichment analysis. We found that circ-014674 may participate in the assembly and reserve of primordial follicles through oestrogen and the Janus kinase (JAK) signal transducer and activator of transcription (STAT) signalling pathway (JAK-SATA). Circ-009346 and circ-017054 may have similar functions and are involved in the activation and growth of primordial follicles through the mitogen-activated protein kinase (MAPK) and phosphoinositide 3-kinase (PI3K) signalling pathways.

CONCLUSIONS

Based on our findings, three circRNAs associated with primordial follicle development were identified, and their potential mechanisms of regulating primordial follicle development were revealed. These findings will help us better understand the molecular mechanism of circRNAs in primordial follicles and provide important references and targets for the development of primordial follicles.

Effect of Growth Factors and Hormones during In Vitro Growth Culture of Cumulus-Oocyte-Complexes Derived from Small Antral Follicles in Pigs

This study evaluated the effect of various growth factors and hormones in an in vitro growth (IVG) medium on the in vitro maturation (IVM) and developmental competence of oocytes derived from small antral follicles (SAFs) in pigs. Cumulus–oocyte complexes (COCs) derived from SAFs were either untreated or treated with epidermal growth factor (EGF), insulin-like factor-1 (IGF-1), insulin, or growth hormone (GH) for 2 days of IVG. Following IVG, COCs were cultured for maturation, and IVM oocytes were induced for parthenogenesis (PA). During IVG, the nuclear maturation of oocytes was significantly increased by the insulin treatment compared to other treatments. Moreover, the insulin treatment significantly increased blastocyst formation after PA relative to the No-IVG, control, EGF, and GH treatments. The cumulus expansion score after IVG-IVM was significantly higher in the insulin group than in the other groups. The glutathione (GSH) contents in IVM oocytes were increased through treatment with IGF, insulin, and GH compared to those of No-IVG oocytes. The level of reactive oxygen species (ROS) in IVM oocytes in all treatment groups was significantly lower after IVG culture than in the No-IVG group. The maturation-promoting factor (MPF) activity after IVM in the insulin-treated oocytes was significantly higher than that of the oocytes treated with EGF, IGF-1, and GH. In conclusion, this study demonstrates that insulin treatment during IVG culture improves the maturational and developmental competence of oocytes derived from SAFs in pigs through its effect on cumulus cell expansion and cytoplasmic microenvironments, such as GSH, ROS, and MPF activity.

Expression of PTX3, GHR and GDF9 genes in cumulus cells and oocytes in relation to developmental competence of Bos indicus

The present study was conducted to evaluate the level of expression (mRNA) of specific developmental marker genes, viz. Growth Differentiation Factor 9 (GDF9), Growth Hormone Receptor (GHR) and Pentraxin 3 (PTX3) in bovine cumulus cells and oocytes in relation to in vitro developmental competence. Good quality Cumulus- Oocytes- Complexes (COCs) were selected for in vitro maturation and fertilization. The mean percentage of in vitro fertilization performance was 59.84 ± 4.28. The relative quantification values of GDF9 were 2.38, 98.13, 1 and 132.58; GHR were 4.31, 1.47, 1 and 43.58; PTX3 were 0.28, 0, 1 and 0.5 in immature cumulus cells, immature oocyte, mature cumulus cells and mature oocyte respectively when compared to the reference control. The expression of GDF9 gene was found to be up-regulated in oocytes compared to cumulus cells. The expression pattern of GDF9 was relatively more in in vitro matured oocytes compared to cumulus groups. The expression of GHR gene was up-regulated in oocytes. The relative abundance of PTX3 was slightly up-regulated in mature cumulus cells as compared to immature counterparts. Thus, GDF9 and GHR genes could be considered as embryonic developmental markers for bovine oocytes, while PTX3 gene for bovine cumulus cells.

Growth hormone protects against ovarian granulosa cell apoptosis: Alleviation oxidative stress and enhancement mitochondrial function

Growth hormone (GH) is a polypeptide hormone that could reduce the mitochondria-mediated oxidative stress and improve the mitochondrial function. However, the mechanisms of GH on granulosa cell apoptosis and mitochondrial function is still unclear. The aim of this study is to determine the effects of GH on granulosa cells apoptosis and the underlying mechanisms. In this study, we exposed the ovarian granulosa cell line (KGN cell) with cisplatin to establish an ovarian granulosa cell apoptosis and mitochondrial dysfunction model in vitro. To examine the benefit of GH in restoration of granulosa cell, we determined cell proliferation, cell apoptosis, reactive oxygen species (ROS) level, the expression of antioxidant components Sod2, Sirt3, as well as the mitochondrial membrane potential and mitochondrial DNA (mtDNA) copy number after GH treatment. We found that the cisplatin exposure significantly inhibited cell proliferation and elevated the apoptotic rate by student's t-test (p < 0.05). Whereas, the GH treatment could rescue the cell proliferation and decrease the apoptotic rate, as well as reduce the Bax/Bcl-2 ratio (p < 0.05). Additionally, GH significantly reduced abnormal ROS levels and increased the level of Sirt3 and Sod2 thus alleviating the oxidative stress. We also found that GH facilitated the recovery of mitochondrial membrane potential and mitochondrial DNA (mtDNA) copy number in granulosa cells. Our results indicated that GH exerted protective effects in cisplatin-induced ovarian granulosa cell apoptosis by alleviating oxidative stress and enhancing mitochondrial function via Sirt3-Sod2 pathway.

Low Dose Growth Hormone Adjuvant Treatment With Ultra-Long Ovarian Stimulation Protocol in Poor Responders Showed Non-inferior Pregnancy Outcome Compared With Normal Responders

Background: Growth hormone (GH) has long been used as adjuvant treatment in ovarian stimulation for in vitro fertilization (IVF), especially in poor responder (PR) patients. However, its clinical efficacy remains unclear, and most studies are underpowered owing to their small sample size with different regimens. Methods: Our study was divided into two parts. The first part was a parallel randomized, observational study in which 184 patients who fulfilled the criteria of poor ovarian response (POR) were enrolled and received ultra-long ovarian stimulation protocol with or without GH adjuvant therapy. For the second part, clinical data were retrospectively extracted from 163 patients classified as PRs who received 10 IU GH adjuvant therapy and 157 patients classified as normal responders (NRs) who received the same IVF protocol treatment without GH adjuvant therapy. Results: For the first part of the study, the ovarian response, the number of oocytes retrieved, and the number of available embryos transferred were all significantly higher in the GH (+) group than in the GH (-) group. The clinical pregnancy rate was significantly higher in the GH (+) group (31.9 vs. 16.7%, p = 0.0168). The miscarriage rate did not differ significantly between the groups. The ongoing pregnancy rate was also significantly higher in the GH (+) group than in the GH (-) group (26.6 vs. 14.4%, p = 0.0418). Logistic regression revealed that the chance of clinical pregnancy in the GH (+) group significant increased 2.34-fold in comparison with the GH (-) group (p = 0.018). Subgroup analysis showed that the chance of clinical pregnancy in the GH (+) group significantly increased 2.38-fold (p = 0.034). The second part of the study showed no statistical difference between the PR with GH and the NR without GH groups regarding the implantation rate (15.6 vs. 19.8%, p = 0.3254) and the clinical pregnancy rate (31.9 vs. 39.5%, p = 0.1565). The NR without GH group showed insignificantly higher chance of clinical pregnancy (OR = 1.39, p = 0.157) compared with the PR with GH group. Conclusion: Our results suggested that low-dose GH supplementation may improve ovarian response and pregnancy outcome in POR patients, particularly in patients younger than 40 years old. Moreover, the low-dose GH effect in POR patients resulted in non-inferior clinical pregnancy outcome compared with NRs.

Is growth hormone administration essential for in vitro fertilization treatment of female patients with growth hormone deficiency?

Available evidence suggests that the fertility of growth hormone deficient female patients could be decreased, although the responsible mechanisms are unknown. Taking into account the multiple effects of growth hormone on reproduction suggested by experimental and clinical studies in women without growth hormone deficiency, the growth hormone deficit by itself could contribute to infertility in these patients. However, the necessity of growth hormone administration and the profile of the infertile patients with growth hormone deficiency who would benefit from treatment are largely unknown. Growth hormone effects on oocyte quality is one of the possible mechanisms through which growth hormone could be involved in fertility of these patients. However, this hypothesis was not tested in patients with adequately diagnosed growth hormone deficiency. We present the case of a 29-year-old female patient with growth hormone deficiency and tubal infertility who was referred for in vitro fertilization treatment. The couple underwent two conventional in vitro fertilization procedures: the first one, without growth hormone treatment and, because no pregnancy was achieved, the second one after growth hormone (somatropinum) administration for 3 months. Although the number of the retrieved oocytes was the same, the quality of the oocytes was improved and their ability to evolve into good quality embryos after fertilization was increased after growth hormone administration. Consequently, the pregnancy was obtained after the second in vitro fertilization treatment and patient gave birth to a healthy boy. In conclusion, our case report suggests that adequate levels of growth hormone are essential for an adequate competence of the oocytes in infertile patients with growth hormone deficiency. Therefore, growth hormone administration should be taken into consideration for patients with this deficiency in order to optimize the results of infertility treatment. Abbreviations: GH: growth hormone; GHD: growth hormone deficiency; HCG: human chorionic gonadotropin; IVF: in vitro fertilization; IGF: insulin like growth factor.

Increased proportion of mature oocytes with sustained-release growth hormone treatment in poor responders: a prospective randomized controlled study

PURPOSE

Supplementation of growth hormone (GH) during controlled ovarian stimulation (COS) has been suggested to improve ovarian response. Despite potential benefits in poor responders, multiple injections of GH during COS are inconvenient. We conducted a randomized controlled study to evaluate the efficacy and safety of sustained-release human GH in poor responders undergoing in vitro fertilization (IVF).

METHODS

This was a single-center, randomized, open-label, parallel study. Infertile women who satisfied the Bologna criteria for poor responders were randomized into GH treatment and control groups. The treatment group received a sustained-release GH (Eutropin Plus^® 20 mg) three times before and during COS (mid-luteal, late luteal, and menstrual cycle day 2). The baseline characteristics and IVF outcomes were compared between the two groups.

RESULTS

A total of 127 patients were included in the analysis. The mean age was 39.6 years and mean anti-Müllerian hormone level was 0.6 ng/ml. There was no significant difference in the baseline characteristics between GH treatment and control groups. The number of follicles on the human chorionic gonadotropin triggering day (3.1 ± 2.3 vs. 2.4 ± 1.6, P = 0.043) and the proportion of metaphase II oocytes (67.5 vs. 52.3%, P = 0.030) were higher in the GH group than in controls. The percentage of clinical and ongoing pregnancy and miscarriage was not different between the two groups.

CONCLUSION

Supplementation of sustained-release GH before and during COS improved ovarian response, with an increase in mature oocytes in poor responders. Further studies are needed to ensure this benefit in general infertility patients.

Growth hormone co-treatment within a GnRH agonist long protocol improves implantation and pregnancy rates in patients undergoing IVF-ET

OBJECTIVE

The efficacy of growth hormone (GH) co-treatment within a GnRH agonist long regimen, in women with a normal ovarian response to controlled ovarian hyperstimulation (COH), for IVF was assessed.

METHODS

This retrospective clinical trial was performed in a private-assisted reproduction centre. The study involved 1114 patients who responded normally to high-dose gonadotropin treatment. The study group of 556 patients was given in a daily subcutaneous injection of 4.5 IU of GH co-treatment, starting from the initial day of gonadotropin treatment and lasting for 5 days. The control group of 558 patients received the same treatment protocol without the GH co-treatment. The participants were further divided into two subgroups: age ≥35 years and age <35 years. The primary endpoint of the study was IVF-ET outcomes.

RESULTS

The demographic characteristics did not significantly differ between the groups. The implantation rate (36.7 vs. 20.4 %, P < 0.05) and clinical pregnancy rate (57.3 vs. 30.1 %, P < 0.05) were significantly higher in the study group than in the control group. An analysis using a multivariate logistic regression model showed that GH was a significant factor for predicting pregnancy outcomes (OR 3.125, 95 % CI 2.441-4.000). Furthermore, for the ≥35-year-old group, the endometrial thickness was significantly greater (11.99 ± 2.21 vs. 11.62 ± 2.45, P < 0.05) in the study group than in the control group; in contrast, for the <35-year-old group, the high-quality embryo rate was significantly higher (71.7 vs. 68.3 %, P < 0.05) in the study group than in the control group.

CONCLUSION

Our study showed that co-treatment with GH in a GnRH agonist long protocol in patients who responded normally while undergoing IVF-ET could increase the implantation and pregnancy rates.

Addition of growth hormone to the microflare stimulation protocol among women with poor ovarian response

OBJECTIVE

To assess the efficacy of adding growth hormone (GH) to the microflare stimulation protocol among women with poor ovarian response.

METHODS

A parallel, open-label, randomized controlled trial was conducted among patients with poor ovarian response who attended a center in Cairo, Egypt, between July 10 and December 31, 2014. Participants were randomly assigned using a computer program (random block size of 4-8) to undergo the microflare protocol with or without GH. Primary outcomes were the mean numbers of mature oocytes retrieved and fertilized. Analyses were done per protocol: women with cycle cancellations were excluded.

RESULTS

The analysis included 72 women in the GH group and 73 in the microflare only group. The mean number of oocytes collected was 7.2±1.5 in the GH group versus 4.7±1.2 in the microflare only group (P<0.001). The mean number of metaphase II oocytes was 5.2±1.2 in the GH group and 2.8±1.0 in the microflare only group (P<0.001). The mean number of fertilized oocytes was higher in the GH group (4.2±1.1) than in the microflare only group (2.5±0.7; P<0.001).

CONCLUSION

Addition of GH to the microflare stimulation protocol provided some potential benefits to women with poor ovarian response. However, further studies are required before it could be recommended for routine clinical use. ClinicalTrials.gov:NCT02185326.

Protein and steroid profiles in follicular fluid after ovarian hyperstimulation as potential biomarkers of IVF outcome

Controlled ovarian hyperstimulation is performed to assist with generation of multiple mature oocytes for use in in vitro fertilization (IVF). The goal of our study was to evaluate differences in protein and steroid profiles in ovarian follicular fluid (hFF) samples obtained during oocyte retrieval from women undergoing IVF treatment and to identify physiological pathways associated with the proteins. The hFF samples were depleted of abundant proteins, fractionated by ultrafiltration, digested, and analyzed by nano-LC-QTOF. Concentrations of 15 endogenous steroids were determined in the samples using LC-MS/MS methods. The total number of proteins identified in the samples was 75, of which 4, 7, and 2 were unique to the samples from women with viable pregnancy, miscarriage, and no pregnancy, respectively. Identified proteins were associated with the acute response signaling, coagulation system, intrinsic and extrinsic prothrombin activation, complement system, neuroprotective role of THOP1, FXR/RXR activation, role of tissue factor, and growth hormone pathways. A greater number of proteins associated with biosynthesis was found in hFF samples corresponding to the oocytes resulting in pregnancy. The abundance of seven proteins was found to be associated with steroidogenesis. The obtained data will contribute to better understanding of the pathogenesis and development of noninvasive markers for assessment of oocytes viability.

Growth hormone and gene expression of in vitro-matured rhesus macaque oocytes

Growth hormone (GH) in rhesus macaque in vitro oocyte maturation (IVM) has been shown to increase cumulus expansion and development of embryos to the 9-16 cell stage in response to 100 ng/ml recombinant human GH (r-hGH) supplementation during IVM. Although developmental endpoints for metaphase II (MII) oocytes and embryos are limited in the macaque, gene expression analysis can provide a mechanism to explore GH action on IVM. In addition, gene expression analysis may allow molecular events associated with improved cytoplasmic maturation to be detected. In this study, gene expression of specific mRNAs in MII oocytes and cumulus cells that have or have not been exposed to r-hGH during IVM was compared. In addition, mRNA expression was compared between in vitro and in vivo-matured metaphase II (MII) oocytes and germinal vesicle (GV)-stage oocytes. Only 2 of 17 genes, insulin-like growth factor 2 (IGF2) and steroidogenic acute regulator (STAR), showed increased mRNA expression in MII oocytes from the 100 ng/ml r-hGH treatment group compared with other IVM treatment groups, implicating insulin-like growth factor (IGF) and steroidogenesis pathways in the oocyte response to GH. The importance of IGF2 is notable, as expression of IGF1 was not detected in macaque GV-stage or MII oocytes or cumulus cells.

Growth hormone and in vitro maturation of rhesus macaque oocytes and subsequent embryo development

PURPOSE

The objective of this study was to use a nonhuman primate model to examine the effects of growth hormone (GH) on oocyte in vitro maturation (IVM).

METHODS

Immunocytochemistry confirmed the presence of GH receptors in rhesus cumulus oocyte complexes and the cytoplasm of embryonic blastomeres. Recombinant human GH (r-hGH) was added to IVM medium and cumulus expansion, nuclear maturation, cytoplasmic maturation and embryo development were analyzed.

RESULTS

Cumulus expansion was highest in the presence of 1 and 10 ng/ml r-hGH. The addition of r-hGH during IVM increased the percentage of embryos progressing to at least the 9-16 cell stage. In a separate study, 100 ng/ml r-hGH was supplemented to IVM and embryo culture medium and no effect was observed.

CONCLUSIONS

The presence of GH receptors along with increased cumulus expansion and embryos progressing to the 9-16 cell stage supports the hypothesis that r-hGH may be involved in oocyte maturation.

Expression and localization of growth hormone and its receptors in the chicken ovary during sexual maturation

Roles of pituitary growth hormone (GH) in female reproduction are well established. Autocrine and/or paracrine actions of GH in the mammalian ovary have additionally been proposed, although whether the ovary is an extra-pituitary site of GH expression in the laying hen is uncertain. This possibility has therefore been assessed in the ovaries of Hy-Line hens before (between 10-16 weeks of age) and after (week 17) the onset of egg laying. Reverse transcription/polymerase chain reaction (RT-PCR) analysis has consistently detected a full-length (690 bp) pituitary GH cDNA in ovarian stroma from 10 weeks of age, although GH expression is far lower than that in the pituitary gland or hypothalamus. GH mRNA is also present in small (>1-4 mm diameter) follicles after their ontogenetic appearance at 14 weeks of age and in all other developing follicles after 16 weeks of age (>4-30 mm diameter). Immunoreactivity for GH is similarly present in the ovarian stroma from 10 weeks of age and in small (<4 mm diameter) and large (>4-30 mm) follicles from 14 and 16 weeks of age, respectively. The relative intensity of GH staining in the ovarian follicles is consistently greater in the granulosa cells than in the thecal cells and is comparable with that in the follicular epithelium. A 321-bp fragment of GH receptor (GHR) cDNA, coding for the intracellular domain of the receptor, has also been detected by RT-PCR in the ovary and is present in stromal tissue by 10 weeks of age, in small follicles (<4 mm diameter) by 14 weeks of age, and in larger follicles (>4-30 mm diameter) from 16 weeks. GHR immunoreactivity has similarly been detected, like GH, in the developing ovary and in all follicles and is more intense in granulosa cells than in the theca interna or externa. The expression and location of the GH gene therefore parallels that of the GHR gene during ovarian development in the laying hen, as does the appearance of GH and GHR immunoreactivity. These results support the possibility that GH has autocrine and/or paracrine actions in ovarian function prior to and after the onset of lay in hens.

Endocrine and ovarian response after a 2-day controlled suckling and eCG treatment in lactating rabbit does

Synchronization methods are used to obtain higher fertility when artificial insemination (AI) is applied to lactating rabbit does. The most common methods are eCG administration or temporary doe-litter separation. Nevertheless, drawbacks have been reported, such as negative side effects of hormonal treatment in the doe and low litter growth due to absence of suckling, respectively. Recently, improved reproductive performance (without visible consequences on young rabbit growth), has been obtained by applying a 2-day controlled nursing method before AI, by allowing for a 10 min nursing of the litter 24 h of separation. The present study was undertaken to examine the pituitary (PRL, LH, FSH) and the ovarian response (follicle size and number) to those methods. A total of 442 lactating does inseminated on day 11 post-partum were distributed in three experimental groups: 2CN (closing of nest box on day 9, controlled nursing on days 10 and 11), eCG (20 IU administered on day 9 post-partum) and CONTROL (untreated). Blood samples were obtained from 10 does per group at 48, 24 and 0 h before AI, and 1h after AI. Both 2CN and eCG treatments similarly improved sexual receptivity (76.3, 77.5 and 58.2%, respectively; P<0.001) and fertility (63.1, 64.1 and 48.4%, respectively; P<0.05) in lactating does, compared to the CONTROL group. Similar plasma FSH levels in all groups of does and sampling times were observed. Due to the absence of suckling, plasma concentration of PRL on day 10 post-partum in the 2CN group was lower than in the CONTROL group (P<0.05); this endocrine change in PRL levels could explain the better reproductive performances obtained with 2CN treatment. At 1h after exogenous administration of GnRH (at the moment of AI) a high LH response was observed in all groups (P<0.001). Ovaries from 20 rabbits treated in the same way but uninseminated (2CN, n=10; eCG, n=5; CONTROL, n=5 does) were obtained on day 11 post-partum in order to check the morphometric status (weight, width and height) and to make histological and immunohistochemical studies to detect growth hormone receptor (GH-R). As a result, synchronization methods did not show any significant difference in relation to the CONTROL group. However, a small increase in the number of primary follicles was evidenced in the 2CN group with respect to the eCG group, similarly to the CONTROL group (23.0+/-3.7, 9.4+/-4.9 and 14.8+/-4.92 primary follicles, respectively; P=0.1). GH-R immunostaining-presence was more evident in the 2CN and the eCG groups, including primordial follicles and oocytes themselves. Thus, there could have been some direct effects of GH on follicular development, as described in other species. Some ovarian parameters described open new ways to study intra-ovarian mechanism of follicular development in the post-partum period of rabbit does.

Impaired growth hormone secretion after glucose loading in non-obese women with polycystic ovary syndrome, possibly related to androgen but not insulin and free fatty acids

BACKGROUND

Secretion of growth hormone (GH) is known to be suppressed in women with polycystic ovary syndrome (PCOS). The suppression may be implicated in the pathogenesis of PCOS.

OBJECTIVE

To investigate the cause of suppressive GH secretion in PCOS.

METHODS

In order to eliminate the influence of obesity on the variables, all subjects were non-obese. Standard oral glucose tolerance tests (OGTT) were performed in 13 normal women and 15 patients with PCOS.

RESULTS

The serum GH level decreased progressively during the OGTT, and the mean area under the curve (AUC) for the GH response was significantly smaller in the PCOS group than in the normal group. A reduction in the level of serum free fatty acids (FFAs) was observed during OGTT, but only the fasting level of FFAs was significantly higher in the PCOS group than in the normal group. The mean AUCs for glucose, insulin and FFA responses in the PCOS group were significantly greater than those in the normal group. There was a significant negative correlation only between AUC(GH) and testosterone (r = -0.4557, p = 0.012).

CONCLUSION

Our findings suggest that the cause of susceptibility for GH secretion to be suppressed after glucose loading in non-obese PCOS patients may be hyperandrogenemia.

Oral clonidine advances spermatogenesis in oligozoospermic patients with spermatogenetic maturation arrest

BACKGROUND

Growth hormone (GH) plays an important role in the pubertal development of males and females, and influences the male reproductive function after puberty. The purpose of this study was to investigate the cause of GH deficiency in infertile men with spermatogenetic maturation arrest using the clonidine loading test (GH stimulation test). Based on the results of the loading test, we tried to con fi rm whether clonidine might be usable as a male infertility remedy.

METHODS

We studied 75 infertile men (55 oligozoospermic and 20 azoospermic men) and 25 normal fertile volunteers. We used the oral clonidine (0.15 mg/m2) loading test to evaluate the GH secretory reserve. Histological diagnoses were performed using testicular biopsy and testicular sperm extraction specimens.

RESULTS

The most important finding was that the clonidine loading test caused a good response in 41 out of 55 (74.6%) patients with oligozoospermia. We treated these 41 good-response patients with oral clonidine, and the sperm count improved in 34 (82.9%) cases, increasing to 12-79 million/mL. Spontaneous pregnancy was subsequently achieved by 10 (24.4%) couples.

CONCLUSIONS

These findings also suggest that GH is necessary for spermatogenesis, at least for the process of spermatozoa maturation. Oral clonidine therapy improved the sperm count in patients who showed an excessive response to the clonidine loading test.

Effect of growth hormone (GH) on in vitro nuclear and cytoplasmic oocyte maturation, cumulus expansion, hyaluronan synthases, and connexins 32 and 43 expression, and GH receptor messenger RNA expression in equine and porcine species

The aim of this study was to investigate the role of growth hormone (GH) on in vitro cumulus expansion and oocyte maturation in equine and porcine cumulus-oocyte complexes (COCs), and to approach its way of action. Equine COCs were cultured in a control medium (TCM199, 5 mg/ml BSA, 1 microg/ml estradiol, and antibiotics) supplemented with either 0.5 microg/ml equine GH or 5 microg/ml equine LH. Porcine COCs were cultured in a basal medium (TCM199 with 570 microM cysteamine) supplemented with 0, 0.1, 0.5, or 1 microg/ml porcine GH or in a control medium (basal medium with 10 ng/ml epidermal growth factor and 400 ng/ml FSH) supplemented with 0 or 0.5 microg/ml porcine GH. After culture, cumulus expansion and nuclear stage were assessed. The cytoplasmic maturation of porcine oocytes was evaluated by in vitro fertilization and development for 7 days. The modifications of the expression of proteins implicated in cumulus expansion were analyzed in equine COCs by SDS-PAGE with antibodies against connexins 32 and 43 and hyaluronan synthases (Has) 1, 2, and 3. The expression of GH receptor mRNA was studied in oocytes and cumulus cells of the two species using reverse transcription-polymerase chain reaction with specific primers. The addition of GH in maturation medium increased cumulus expansion in equine but not porcine COCs. It improved nuclear maturation in equine and porcine, but had no effect on porcine fertilization and embryo development. The GH receptor mRNA was detected in equine and porcine oocytes and cumulus cells. GH did not influence the expression of Has 1, Has 3, and connexin 43 in equine cumulus cells.

Pelvic ultrasound evaluation in patients with Turner syndrome during treatment with growth hormone

OBJECTIVES

Treatment with growth hormone (GH), alone or in combination with oxandrolone, is used in patients affected by Turner syndrome to improve growth velocity and adult height. Since GH interacts with gonadotropins in the stimulation of the human ovary, the aim of our study was to evaluate the possible effects of GH administration on uterine and ovarian characteristics.

METHODS

We performed pelvic ultrasound assessment in 29 patients with Turner syndrome aged 7.5-16.6 years (19 with 45,X karyotype; 10 with variant karyotypes) before and during treatment with GH alone. Uterine volume and ovarian size and morphology were compared to those of 23 age-matched girls with Turner syndrome not treated with GH. Both patients and controls were divided into prepubertal and pubertal groups. Cross-sectional and longitudinal studies (before and every 6 months during GH treatment for 2 years) were performed.

RESULTS

We observed a significantly higher uterine anteroposterior diameter and volume in younger (< or = 11 years) GH-treated Turner syndrome girls than in those who were untreated. Also visualization and heterogeneous echopattern of the ovaries were significantly more frequent in treated than in untreated Turner syndrome patients, particularly before the age of 11 years. The longitudinal study showed a significant increase in uterine volume, more related to treatment than to age. Spontaneous breast development and menarche were found more frequently in GH-treated Turner syndrome girls.

CONCLUSION

Growth hormone therapy can have a co-gonadotropin role in patients with Turner syndrome.

Growth hormone-related effects on apoptosis, mitosis, and expression of connexin 43 in bovine in vitro maturation cumulus-oocyte complexes

Pituitary LH and FSH are known to be the major regulators of ovarian function. In the last few years, however, there has been evidence that growth hormone (GH) is also involved in ovarian regulation. Therefore, the aim of our study was to elucidate the mechanisms of GH action during in vitro maturation (IVM) of bovine cumulus-oocyte complexes (COCs). As shown by detection of the nuclear cell proliferation-associated antigen Ki-67, COCs matured in vitro in the presence of GH revealed a significantly (P < 0.05) higher proportion of proliferating cumulus cells (12.6%) compared with the COCs matured in the control medium TCM 199 (9.9%). In contrast, the percentage of proliferating cells was not increased by supplementation of the medium with a combination of GH and insulin-like-growth factor I (IGF-I). Apoptosis as determined by TUNEL (terminal doxynucleotidyl transferase mediated dUTP nick-end labeling) was significantly (P < 0.05) reduced in the cumulus cells by GH treatment. COCs matured with a combination of GH and IGF-I revealed the lowest percentage of apoptotic cells (11%). The localization and quantification of the gap junction protein connexin 43 (Cx 43) demonstrated that GH induced a significant decrease in the synthesis of the Cx 43 protein in the cumulus cells. Our results imply that GH increases cumulus expansion by promotion of cell proliferation and inhibition of apoptosis. Whereas the increase in cell proliferation is a direct effect of GH, the antiapoptotic effects of GH during in vitro maturation are modulated by IGF-I. Stimulatory effects of GH on oocyte maturation are correlated with changes in the synthesis of gap junction proteins.

Insulin-like growth factors and their binding proteins: Potential relevance to reproductive physiology

Cyclic ovarian follicular development is a complex process that involves proliferation, differentiation, and death of follicle cells. Gonadotropins produced by the pituitary gland have a central role in the regulation of these processes. In addition, a wide range of paracrine and autocrine factors produced in the reproductive organs have been proposed as regulators of reproductive functions. Components of the insulin-like growth factors (IGF) system are widely expressed in the female reproductive tract. The IGFs and their binding proteins play a significant role in several processes of reproductive physiology, including ovarian follicular development, oogenesis and oocyte maturation, ovulation, luteal function, follicular atresia, and testicular function. The majority of these physiological actions of the IGFs are believed to occur via activation of the IGF-I receptor, although the IGF-I effects are modulated by IGF binding proteins (IGFBPs). As much of the data obtained to date have been in the rodent reproductive organs, it may not be possible to directly extrapolate the results to the primate organs. There is a distinct species-difference in the gene expression and functional roles of the IGF-IGFBP system in reproductive organs. However, the disturbance of the IGF-IGFBP system in human reproductive physiology may lead to anovulation, disorders of androgen excess, infertility associated with implantation failure, and male infertility. Further research is needed in domestic animals to determine if manipulation of the IGF-IGFBP system may result in improved reproductive efficiency. As our understanding of the IGF-IGFBP system increases, the uses of human recombinant IGF peptides and IGFBPs as clinical therapy for disease states is becoming a reality. (Reprod Med Biol 2003; 2: 1-24).

The role of growth hormone in fetal development

Studies across several species, particularly the mouse, show that growth hormone (GH, somatotrophin) is an important determinant of litter size, and to a lesser extent, of birth length. GH acts at all stages of development, from ovulation through preimplantation development to the late fetus, with actions on both embryo/fetus and mother contributing to successful fetal development. The fact that these are not more obvious in vivo is likely a result of redundancy of cytokine hormone action, particularly in relation to prolactin, which shares common actions and receptor locations with GH.

IGF-1 in gynaecology and obstetrics: update 2002

Recent discoveries on endocrine, paracrine and autocrine involvement of insulin-like growth factor-1 (IGF-1) in the proliferation of many tissues raised the attention of its role in reproduction and in the growth of various cancers as well as of benign proliferations. The intention of this article is to focus on IGF-1 in the field of gynaecology. Perimenopausal women who exhibit high IGF-1 and low IGF binding protein (IGFBP) levels, like IGFBG-3, have an increased risk of developing breast cancer. A higher risk for cervical, ovarian and endometrial cancer is related to high IGF-1 levels in post- and premenopausal women. It has been shown that myomas, by far the most common benign uterine tumor in women, grow in the presence of IGF-1, in vitro as well as in vivo. Studies show that IGF-1 is involved in the differentiation of various reproductive tissues, like endometrium and ovarian tissues. Patients suffering from polycystic ovary syndrome (PCO) frequently show insulin resistance accompanied by an increase of IGF-1 in plasma. Plasma IGF-1 levels are higher in cases of severe endometriosis, however, in endometriosis and in PCO IGF levels locally in the endometrium are reduced, what might explain infertility. Recently, it was shown that IGF facilitates the implantation of the human embryo in the endometrium during IVF. Implantation is a paradox where different immune systems have to collaborate to make implantation and survival of the pregnancy possible. IGF seems to be the starter molecule so that the two epithelia can fuse. A disturbance can result in complications during pregnancy i.e. spontaneous miscarriage, preeclampsia as well as defects of the embryo. Therefore, IGF is a useful marker in successful pregnancy as well. A better mechanistic understanding of IGF-1 action on the cellular level not only provides more elegant mechanistic explanations for the scientist, but the practitioner might find it interesting to utilize its diagnostic potential as a marker for various diseases. The relation between systemic IGF levels and local tissue IGF-1 levels has not yet been determined for all conditions.

Improved responsiveness of PCOS patients to clomiphene after CYP17a inhibitor

PURPOSE

To study the effect of CYP17a inhibitor, "ketoconazole," on clomiphene responsiveness in PCOS patients.

METHODS

Prospective analysis was employed with the setup at Alexandria IVF/ICSI center. Ninety-seven insulin-resistant PCOS patients undergoing ovulation induction using clomiphene citrate were randomly divided, by random number table, into two groups. The first group (n = 49) received ketoconazole (400 mg daily) till correction of metabolic syndrome followed by clomiphene (100 mg/day); the second group (n = 48) receiving clomiphene without ketoconazole pretreatment. Main outcome measures were incidence of clomiphene resistance, monofollicular response, fasting insulin/glucose ratio, serum testosterone, and pregnancy rates.

RESULTS

The ketoconazole group showed significantly (p < 0.05) higher incidence of monofollicular response (38%), higher pregnancy rates, and significantly less marked antiestrogenic manifestations than did the control group. They also had significantly lower incidence of clomiphene resistance (11.6%), lower serum testosterone levels, less hyperinsulinaemia, than did the control group.

CONCLUSION

Ketoconazole improved clomiphene responsivenss in PCOS patients and attenuated its untoward biological effects.

Preimplantation bovine embryos express mRNA of growth hormone receptor and respond to growth hormone addition during in vitro development

In previous studies we demonstrated that bovine cumulus oocyte complexes (COCs) obtained from small and medium sized follicles express growth hormone receptor (GHR) mRNA and respond to growth hormone (GH) addition during in vitro maturation. The aim of this study was to investigate whether bovine zygotes and preimplantation embryos continue the expression of GHR gene after in vitro fertilization and during early embryo development and whether supplementation of GH during embryo culture affects embryo development. Therefore, COCs obtained from small and medium sized follicles were cultured in M199 supplemented with 10% FCS and gonadotropins for 24 hr. After in vitro fertilization the embryos were cultured: (a) on a monolayer of buffalo rat liver (BRL) cells in M199 supplemented with 10% FCS and 100 ng/ml bovine GH (NIH-GH-B18); (b) in droplets of serum-free BRL-conditioned medium supplemented with 100 ng/ml GH; (c) in droplets of synthetic oviductal fluid (SOF) supplemented with 100 ng/ml GH. Cultures without GH served as controls. Embryos were scored morphologically and the efficiency of the culture system was evaluated (a) as the percentage of cleaved embryos 4 days after IVF, (b) the percentage of blastocysts on Day 9 expressed on the basis of the number of oocytes at the onset of culture, and (c) the percentage of hatched blastocysts on Day 11 expressed on the basis of the total number of blastocysts present at Day 9. For gene expression, immature (GV) and mature (MII) oocytes (as positive control), embryos with less than 8 cells, 16-32 cells, and hatched blastocysts were prepared for reverse transcriptase polymerase chain reaction (RT-PCR) to assess the expression of mRNA of GHR. Messenger RNA for GHR was found in GV and MII oocytes and in all stages of embryo development. No mRNA for GH could be detected in early and expanded blastocysts produced in SOF medium. Immunoreactive GHR was found both in trophoblastic and embryonic cells of hatched blastocysts. Addition of 100 ng/ml GH during embryo culture on a monolayer of BRL cells in M199 supplemented with 10% FCS did not affect embryo development. However, GH (100 ng/ml) supplementation during embryo culture in droplets of serum-free BRL conditioned medium significantly (P < 0.05) enhanced the proportion of > 8-cell embryos. Similarly, culture of embryos in droplets of SOF medium in the presence of GH (100 ng/ml) significantly (P < 0.05) enhanced the number of > 8-cell embryos from 53.8% in control to 70.6% in GH-treated group. Day 9 blastocyst formation in SOF medium was also significantly (P < 0.01) increased in the presence of GH (33.9%) compared to the control (20.2%). Embryos cultured in SOF without GH rarely resulted in hatched blastocysts (0.7%). However, GH supplementation remarkably enhanced the proportion of the hatched blastocysts (13%). In conclusion, expression of GHR gene in preimplantation bovine embryos, presence of the receptor, and the beneficial effect of GH on cleavage, blastocyst formation and hatchability of the embryos point to the involvement of GH in early embryonic development.

Effect of growth hormone releasing hormone (GHRH) and vasoactive intestinal peptide (VIP) on in vitro bovine oocyte maturation

The aim of this study was to investigate the effects of growth hormone releasing hormone (GHRH) and the structural-related peptide vasoactive intestinal peptide (VIP) on nuclear maturation, cortical granule distribution and cumulus expansion of bovine oocytes. Bovine cumulus oocyte complexes (COCs) were cultured in M199 without FCS and gonadotropins and in the presence of either 100 ng/mL bovine GHRH or 100 ng/mL porcine VIP. The COCs were incubated at 39 degrees C in a humidified atmosphere with 5% CO2 in air, and the nuclear stage was assessed after 16 or 24 h of incubation using DAPI staining. Cortical granule distribution was assessed after 24 h of incubation using FITC-PNA staining. To assess the effects of GHRH and VIP on cumulus expansion, COCs were incubated for 24 h under the conditions described above. In addition, 0.05 IU/mL recombinant human FSH was added to GHRH and VIP groups. Cultures without GHRH/VIP/FSH or with only FSH served as negative and positive controls, respectively. At 16 h neither GHRH (42.9%) nor VIP (38.5%) influenced the percentage of MII stage oocytes compared with their respective controls (44.2 and 40.8%). At 24 h there also was no difference in the percentage of MII oocytes between GHRH (77.0%), VIP (75.3%) and their respective controls (76.0 and 72%). There was no significant cumulus expansion in the GHRH or VIP group, while FSH induced significant cumulus expansion compared with the control groups, which were not inhibited by GHRH or VIP. Distribution of cortical granules was negatively affected by GHRH and VIP. The percentage of oocytes showing more or less evenly dispersed cortical granules in the cortical cytoplasm aligning the oolemma (Type 3) was lower in the GHRH (2.7%) and VIP (7.8%) groups than in the control group (15.9%). In conclusion, GHRH and VIP have no effect on nuclear maturation or cumulus expansion of bovine COCs but retard cytoplasmic maturation, as reflected by delayed cortical granule migration.

Messenger RNA expression and protein localization of growth hormone in bovine ovarian tissue and in cumulus oocyte complexes (COCs) during in vitro maturation

The aim of this study was to investigate whether bovine cumulus oocyte complexes (COCs) obtained from 2 to 8 mm follicles synthesize growth hormone (GH) during in vitro maturation. In addition the expression of growth hormone releasing hormone receptor (GHRH-r) in the COCs before and after in vitro maturation was investigated. Therefore, COCs obtained from small and medium sized follicles were cultured in M199 supplemented with 10% FCS and gonadotropins for 24 hr. At 0, 6, 12, and 24 hr after the onset of culture, COCs were removed and were prepared for immunohistochemical staining to detect the presence of GH. In addition, sections of ovary were stained to study the differential localization of GH in the ovary. At 0 and 24 hr COCs were removed and together with samples from granulosa cells and theca cells were prepared for reverse transcriptase polymerase chain reaction (RT-PCR) to assess the expression of mRNA of GH and GHRH-r. Within COCs, cumulus cells and oocytes showed GH immunoreactivity, while expression of GH mRNA was only found in the oocyte. At the onset of culture, oocytes and cumulus cells in the majority of COCs generally showed moderate and strong staining intensity for GH, respectively. While GH staining in the cumulus cells did hardly change during 24 hr of culture, GH staining in the oocyte was absent after 24 hr of culture in 70% of COCs. Within the ovary, GH was localized in antral follicles larger than 2 mm and no staining was found in primordial, primary and secondary follicles or in the stroma. The intensity of the staining increased with the size of the follicles. Within the follicular wall the GH was persistently observed in granulosa cells, while theca cells were occasionally negative. GH mRNA in follicular compartments was only found in the oocyte and mural granulosa cells. No GHRH-r mRNA was found in the COCs nor in the granulosa or the stroma. In conclusion, the gradual increase of GH staining during follicular development and the consistent synthesis of GH in oocytes and granulosa cells, suggest a paracrine and/or autocrine action for GH in bovine follicular growth and oocyte maturation. The absence of mRNA for GHRH receptor in the COCs indicates that ovarian production of GH is not regulated by GHRH.

Insulin-like growth factors and ovarian physiology

OBJECTIVE

To review the available information regarding the roles of insulin-like growth factor (IGF)-IGF binding protein (IGFBP) system in ovarian physiology.

DESIGN

Studies that specifically relate to the roles of ovarian folliculogenesis, oocyte maturation, and ovulation were identified through the literature and Medline searches.

RESULTS

Numerous actions of the IGFs have been demonstrated in the ovary, including an enhancement of cell proliferation, aromatase activity, and progesterone biosynthesis. The ovarian IGF system, comprised of IGF-I and IGF-II peptides, IGFBPs and IGF receptors, plays a significant role in the process of follicular development. In addition, IGF-I stimulates the meiotic maturation of follicle-enclosed oocytes in vitro via the IGF-I receptors. IGFBP-3 significantly inhibit gonadotropin-induced ovulation and oocyte maturation by neutralizing endogenously produced IGF-I. Thus, the intraovarian IGF-IGFBP system play a significant role in the processes of follicular development, oocyte maturation, and ovulation.

CONCLUSION

IGF-IGFBP systems have autocrine/paracrine regulatory actions in ovarian physiology. The disturbance of the IGF-IGFBP system in human ovaries may lead to an ovulation, disorders of androgen excess, and infertility.

Developmental changes in the expression of the growth hormone receptor messenger ribonucleic acid and protein in the bovine ovary

By reverse transcription-polymerase chain reaction, the transcript of the growth hormone receptor (GHR) was demonstrated in oocytes, follicular cells, and corpus luteum of the bovine ovary. Immunoblotting using the monoclonal antibody mAb 263 resulted in a distinct protein band at 120 kDa, confirming that translation of the mRNA takes place in the same cells. Nonradioactive in situ hybridization revealed that distribution of the mRNA encoding GHR was correlated with the developmental stage of the follicle. Whereas in primordial and primary follicles the oocyte showed distinct amounts of the transcript encoding GHR, in tertiary follicles the mRNA was predominantly localized in the cells of the cumulus oophorus. GHR mRNA was also expressed in the large granulosa lutein cells, in the germinal epithelium, and in the endothelial cells of ovarian vessels. Colocalization of the GHR protein showed a distribution pattern identical to that of the mRNA. In calves, oocyte and follicle cells changed GHR expression in the same way as in the adult ovary. During embryonic development of the ovary, distinct amounts of the mRNA encoding GHR were found in primordial follicles shortly before birth. Our results imply that the GHR is involved in ovarian ontogenesis, especially in early folliculogenesis.

Effect of growth hormone suppression on the serum levels of ovarian and adrenal sex steroid hormones in normal women and in women with polycystic ovary syndrome

We investigated the acute effect on the serum levels of ovarian and adrenal sex steroid hormones of the suppression of growth hormone during oral glucose tolerance test (OGTT). A standard 75 g OGTT was performed in 11 healthy women and eight women with polycystic ovary syndrome (PCOS). Another five controls were given a sham loading of oral distilled water. Blood samples were obtained immediately before and at 30-minute intervals after glucose or sham loading. Significant progressive declines in testosterone, estradiol, dehydroepiandrosterone sulfate (DHEAS) and growth hormone levels were observed during OGTT in both groups. In the PCOS and normal groups, respectively, at 120 min, testosterone levels were 75.8% and 64.4% of the baseline (0-time) value, estradiol levels were 83.4% and 83.1%, DHEAS levels were 79.3% and 79.1%, and growth hormone levels were 33.9% and 21.2%. Significant positive correlations were observed between the level of growth hormone and each of the testosterone, estradiol and DHEAS levels in both the groups. The area under the curve for growth hormone was significantly smaller in the PCOS group than in the normal group. Gonadotropins were not changed at any time during OGTT. It appears that growth hormone may modify ovarian and adrenal sex steroidogenic responses to tropic hormones directly or via local insulin-like growth factor-I. Women with PCOS may be relatively deficient in growth hormone, a deficiency which may play a role in the pathophysiology of ovulatory disturbance.

In vitro maturation of bovine oocytes in the presence of growth hormone accelerates nuclear maturation and promotes subsequent embryonic development

Regulatory effect of GH on follicular growth and development in the cow is well documented. The aim of this study was to investigate the role of GH on in vitro bovine oocyte maturation. Therefore bovine cumulus oocyte complexes (COCs) were cultured in M199 without FCS and gonadotropins and in the presence of 10, 100, or 1,000 ng/ml bovine GH (NIH-GH-B18). The COCs were incubated at 39 degrees C in a humidified atmosphere with 5% CO2 in air and nuclear stage was assessed after 2, 4, 8, 16, 22, and 24 hr of incubation using DAPI staining. To assess the effect of GH on developmental capacity of the oocytes, COCs were incubated in the presence of GH for 22 hr, followed by IVF and in vitro embryo culture. Cultures without GH served as controls. For subsequent development, the embryos were cultured in M199 supplemented with 10% FCS on a monolayer of BRL cells. Embryos were scored morphologically and the efficiency of the culture system was evaluated as (1) the percentage of cleaved embryos 4 days after IVF, (2) the percentage of blastocysts on day 9 expressed on the basis of the number of oocytes at the onset of culture, and (3) the percentage of hatched blastocysts on day 11 expressed on the basis of the total number of blastocysts present at day 9. GH (100 and 1,000 ng/ml) significantly accelerated nuclear maturation (P < 0.001). At 4 and 8 h the percentage of oocytes in GV stage after GH treatment (54% and 19%) was significantly lower than the control (64% and 41%). Similarly at 16 and 22 h the percentage of oocytes in MII stage was significantly higher in the GH-treated group; (58% and 77%) and (46% and 62%) for GH and control respectively. The number of oocytes in MII beyond 22 hr of culture did not differ; 100 and 1,000 ng/ml GH induced significant cumulus expansion (P < 0.05), which was not observed in the absence of GH. Addition of 100 and 1,000 ng/ml GH during maturation significantly (P < 0.01) enhanced subsequent cleavage rate from (64% and 67%) in control to (75% and 81%) in GH-treated group; embryonic development in terms of day 9 blastocyst formation was also significantly increased in the presence of GH (29% and 34%) compared to the control (18% and 24%). The hatchability of the blastocysts was not influenced by GH. From the present data, it can be concluded that GH present during IVM has a beneficial effect on subsequent development.

Insulin-like growth factor (IGF)-I and IGF-II stimulate progesterone production by human luteal cells: role of IGF-I as mediator of growth hormone action

OBJECTIVE

To examine the possible direct effect of insulin-like growth factor (IGF)-I and IGF-II on basal and hCG-stimulated P production by cultured human luteal cells. The possible role of IGF-I as mediator of GH action on luteal steroidogenesis also was investigated.

DESIGN

Cultures of human luteal cells from early and midluteal phase.

SETTING

All corpora lutea were obtained from the Obstetrics and Gynecology Department of the Universita Cattolica, a public care center.

PATIENTS

Eight nonpregnant women between 35 and 47 years of age underwent surgery for various nonendocrine disorders such as leiomyomatosis.

INTERVENTIONS

Corpora lutea were obtained at the time of hysterectomy.

MAIN OUTCOME MEASURES

Luteal cells were incubated with IGF-I or IGF-II with or without hCG at different concentrations. Growth hormone also was used alone and with an anti-IGF-I-antibody.

RESULTS

We found that IGF-I and IGF-II were able to stimulate directly the P production at all used concentrations and that both of them significantly amplified the steroidogenic hCG effect. Finally, IGF-I was shown to mediate the positive GH action on P synthesis.

Behavioral and endocrine effects of growth hormone administration in aged female rats

Growth hormone (GH) secretion declines during normal aging along with reproductive activity in mammalian species. Various behavioral changes also occur in aged animals. In these experiments we have studied the effects of GH administration on behavioral and endocrine alterations exhibited by aged (18 months old) female rats of the Sprague-Dawley strain. Animals were selected showing at least 2 weeks of cornified vaginal smears (constant estrous) and treated with GH (0.1 mg/kg SC) daily for 8 weeks. Vaginal smears performed during the drug treatment revealed a recovery of estrous cycle in 60% of animals. GH treatment was also followed by an increased acquisition of shuttle-box active avoidance behavior and a facilitated retention of passive avoidance response. Compared to saline-injected controls, female rats treated with GH also exhibited a decrease of novelty-induced excessive grooming. The endocrine pattern of GH-treated aged female rats revealed a decrease in plasma prolactin levels and an increase in luteinizing hormone and 17 beta-estradiol levels as compared to those of control animals. These results support the concept that behavioral and endocrine alterations occurring in aging are not irreversible and that GH may interfere with these changes probably by means of its trophic action on different target organs.

Interaction among bovine somatotropin, insulin, and gonadotropins on steroid production by bovine granulosa and thecal cells

The objective of the present study was to determine the interactions among bST, insulin, and gonadotropins on steroid production by granulosa and thecal cells from bovine follicles. Basal production of estradiol by granulosa cells from small (1 to 5 mm) and large (> or = 8 mm) follicles (expressed as picograms of estradiol per 10(5) cells per 24 h) was not affected by 50 or 300 ng/ml of bST, but 300 ng/ml of bST inhibited estradiol production that was induced by FSH plus insulin in cells from small and large follicles. Progesterone production and proliferation by granulosa cells from large follicles were not affected by 3 to 100 ng/ml of bST. In cultures of thecal cells that exhibited a > 3-fold increase in androstenedione production induced by LH, 3 to 30 ng/ml of bST further increased androstenedione production by 29 to 42%, but cell proliferation and progesterone production were unaffected by bST. In cultures of thecal cells that exhibited a < 2-fold increase in androstenedione production induced by LH, 3 to 30 ng/ml of bST inhibited androstenedione production by 32 to 33% and inhibited cell proliferation by 9 to 13%, but progesterone was unaffected by bST. In summary, only pharmacologic doses of bST inhibited estradiol production by granulosa cells, but physiologic doses of bST altered androstenedione production by thecal cells, which indicated that bST might not have an important role in granulosa cell function but might play a role in thecal cell function in cattle.

Growth hormone stimulates androsterone synthesis by rat theca-interstitial cells

The aim of this study was to assess the possible role of growth hormone (GH) on androsterone synthesis. This effect was analyzed in theca-interstitial cells obtained from immature female rats. The addition of GH to the cultures significantly stimulated androsterone (A) synthesis in a dose- and time-dependent way and this effect was not due to a cellular number increase. When added to the hCG cultures, GH significantly enhanced androgen production even though it did not synergyze with the chorionic gonadotropin. The addition of antibodies anti-IGF-I to the GH cultures did not modify the growth hormone effect suggesting that GH probably does not require IGF-I to achieve its effect on A production. Finally, no effect of GH on cAMP levels were observed in the cultures at the end of the treatment. Our results demonstrate that GH is able to significantly induce A synthesis by rat theca-interstitial cells. Since the presence of GH and its receptors in the ovary is now well established the present data strongly suggest a potential relevance of GH in reproductive biology.

Effects of growth hormone and growth hormone-releasing hormone on steroid synthesis in cultured human luteinizing granulosa cells

To assess the direct effect of growth hormone and growth hormone-releasing hormone on gene expression of steroidogenic enzymes and production of progesterone, 17-hydroxyprogesterone (17-OHP) and estradiol, we cultured luteinizing granulosa cells with or without follicle-stimulating hormone (FSH), growth hormone and growth hormone-releasing hormone at different concentrations. Luteinizing granulosa cells were obtained from women undergoing an in vitro fertilization program in the Department of Obstetrics and Gynecology, S. Raffaele Scientific Institute, Milan, Italy. At a concentration of 1 microgram/ml, FSH significantly increased estradiol production (2.1 +/- 0.7-fold the control value; p < 0.05 vs. control) and progesterone production (3.5 +/- 2.0-fold the control value; p < 0.05 vs. control). Growth hormone was effective on estradiol, progesterone and 17-OHP at 1 microgram/ml, enhancing estradiol production (1.3 +/- 0.2-fold the control value; p < 0.05 vs. control), progesterone production (2.5 +/- 1.0-fold the control value; p < 0.05 vs. control), and 17-OHP (1.4 +/- 0.2-fold the control value; p < 0.05 vs. control). Growth hormone-releasing hormone increased estradiol production (1.5 +/- 1.2-fold the control value) and progesterone production (1.3 +/- 0.8-fold the control value), but not significantly. No effects by growth hormone-releasing hormone were seen on 17-OHP production. FSH, growth hormone and growth hormone-releasing hormone did not increase P450scc and P450 aromatase mRNAs, whereas FSH increased P450c17 mRNA to 150% at 100 ng/ml and 1 microgram/ml, growth hormone increased it to 230% at 100 ng/ml and to 200% at 1 microgram/ml, and growth hormone-releasing hormone increased it to 140% at 100 ng/ml and to 190% of control values at 1 microgram/ml. These results indicate a direct effect of growth hormone on steroidogenesis by increasing P450c17 mRNA accumulation and progesterone, 17-OHP and estradiol production.

Growth hormone induces in vitro maturation of follicle- and cumulus-enclosed rat oocytes

The aim of this study was to assess the possible role of growth hormone (GH) on rat oocyte maturation. This effect was analyzed in follicle-enclosed, cumulus-enclosed and denuded oocytes obtained from immature pregnant mare's serum gonadotropin (PMSG)-treated rats. The addition of GH to the cultures significantly accelerated maturation in both follicle- and cumulus-enclosed oocytes while no effect was seen on denuded oocytes maturation. Also, GH accelerated meiotic maturation in follicle-enclosed oocytes from immature untreated rats. The GH action was not mediated by lactogenic receptors since prolactin (Prl) did not affect the maturation process while it was mediated by insulin growth factor-I (IGF-I) as suggested by the block of GH action observed in the presence of antibodies anti-IGF-I. Finally, no GH effect was found when dbcAMP was added to the cultures. Our results demonstrate that GH is capable of inducing maturation in oocytes from both primed and unprimed rats. Since the presence of physiological levels of GH in the ovary is now well established, the present data strongly suggest a potential relevance of GH in the reproductive biology.

The role of growth hormone in ovulation induction

During the last few years the potential importance of intraovarian regulators of follicular development has been recognized, and the effects of various growth factors on granulosa cell responses to gonadotrophins have been extensively investigated. Ovarian responses to exogenous gonadotrophins were improved by adjuvant growth hormone (GH) treatment of GH-deficient patients, and responses to hMG were apparently predicted by estimated GH reserve. However, the results of different studies of GH/hMG cotreatment were equivocal. Therefore, a randomized, prospective, cross-over study protocol between GH/hMG/hCG versus hMG/hCG was undertaken. Whereas 16 pregnancies were achieved in the 26 Clonidine-negative patients (61.5%) either in the GH/hMG cycle (11) or in the succeeding one (5), no benefit was detected in 8 Clonidine-positive patients from the GH/hMG combination. The recently described GH-binding protein (BP) may reflect the GH-receptor. GH-BP levels were evaluated in the sera and follicular fluids (FF) of patients undergoing ovulation induction with either hMG/hCG or GH/hMG/hCG. GH-BP increase in serum correlated with E2, and progesterone (P4) concentrations. The FF GH-BP correlated with serum GH-BP levels. Lower FF GH-BP levels were measured in older compared to younger women, while increased values were obtained both in patients with elevated E2 concentrations in serum and in FF, or when more than five oocytes were retrieved. Primary increased GH-BP in unexplained infertility may suggest a new mechanism whereby excessive GH-BP levels may deprive GH from its receptor and thus decrease the introavarian IGF-I production.(ABSTRACT TRUNCATED AT 250 WORDS)

Interleukin-1 beta, interleukin-6, and growth hormone levels in human follicular fluid

PURPOSE

To investigate possible relationships of interleukin-1 beta (IL-1 beta), interleukin-6 (IL-6), and growth hormone (GH) with biochemical variables in human follicular fluid (FF) and selected in vitro fertilization (IVF) parameters.

METHODS

A total of 67 FF samples (n = 67 patients undergoing oocyte retrieval for IVF) was evaluated. IL-1 beta, IL-6, GH, hLH, FSH, PRL, hCG, testosterone, total protein, fibrinogen, sialic acid, alpha 1-antitrypsin, plasminogen levels, and spectrophotometric absorbance at 458 nm were analyzed for selected FF. IL-6 and GH levels of serum and FF samples were also compared (n = 23).

RESULTS

Immunoreactive levels of IL-1 beta, IL-6, and GH were detected in all FF samples. A positive correlation existed for IL-6 (r = 0.5069, P = 0.0161) when serum-to-FF levels were compared (concentration ratio, 1:1.857). Smaller-volume follicles (< 4 ml) were associated with high IL-1 beta levels (P = 0.0229), and an additional tendency of IL-1 beta to decrease with increasing embryo cleavage and scoring was observed. With the exception of a weak positive correlation between follicular IL-1 beta and testosterone levels (r = 0.3128, P = 0.025), no other relationship with biochemical variables or IVF parameters (etiology, e.g., endometriosis) could be implicated.

CONCLUSIONS

Substantially higher IL-6 levels occurred in FF compared to serum, thus supporting intrafollicular production. Interleukin-1 beta, IL-6, and GH levels in FF are, however, unsuitable markers for in vitro fertilization outcome.

Direct ovarian effect of growth hormone in the rabbit

PROBLEM

This study was undertaken to assess whether growth hormone (GH) can stimulate follicle growth and ovarian steroidogenesis via putative GH receptors.

METHOD

In vitro perfused rabbit ovary.

RESULTS

Ovulation occurred in neither the control ovaries nor experimental ovaries treated with 100 ng/ml of GH, whereas all ovaries exposed to 50 IU of human chorionic gonadotropin (hCG) ovulated. The addition of GH to the perfusate significantly stimulated the follicle growth in the absence of gonadotropin. The percent change in follicle diameter in GH-treated ovaries did not differ significantly from that in hCG-treated ovaries. Exposure to GH significantly stimulated the meiotic maturation in the follicular oocytes, as compared with the contralateral control ovaries. Although the concentration of progesterone in the perfusate did not differ significantly between GH-treated and control ovaries, GH stimulated estradiol production by the perfused rabbit ovaries. Rabbit ovary membranes exhibited high affinity binding sites of hGH (Kd = 6.1 x 10(-9) M).

CONCLUSION

GH acts on the rabbit ovary to stimulate the follicle growth, oocyte maturation, and ovarian estradiol production by interacting with the specific receptors located in ovarian plasma membranes.