Progress in understanding human ovarian folliculogenesis and its implications in assisted reproduction.

PURPOSE: To highlight recent progress in understanding the pattern of follicular wave emergence of human menstrual cycle, providing a brief overview of the new options for human ovarian stimulation and oocyte retrieval by making full use of follicular physiological waves of the patients either with normal or abnormal ovarian reserve. METHODS: Literature review and editorial commentary. RESULTS: There has been increasing evidence to suggest that multiple (two or three) antral follicular waves are recruited during human menstrual cycle. The treatment regimens designed based on the theory of follicular waves, to promote increased success with assisted reproduction technology (ART) and fertility preservation have been reported. These new options for human ovarian stimulation and oocyte retrieval by making full use of follicular waves of the patients either with normal or abnormal ovarian reserve lead to new thinking about the standard protocols in ART and challenge the traditional theory that a single wave of antral follicles grows only during the follicular phase of the menstrual cycle. CONCLUSIONS: The understanding of human ovarian folliculogenesis may have profound implications in ART and fertility preservation. Further studies are needed to evaluate the optimal regimens in ART based on the theory of follicular waves and to identify non-invasive markers for predicting the outcome and the potential utilities of follicles obtained from anovulatory follicular waves in ART.

Regulation of AMH and SCF expression in human granulosa cells by GnRH agonist and antagonist.

With the progress of cancer treatment, fertility preservation has become an urgent requisition. Gonadotropin-releasing hormone agonist (GnRH-a) and antagonist (GnRH-ant) have been used to protect fertility for these patients. However, studies showed that although GnRH-a and GnRH-ant had a comparable down-regulating effect on the pituitary, GnRH-ant could not preserve ovarian function. Moreover, GnRH-ant alone could deplete primordial follicles. It might be speculated that an additional intraovarian system existed except the pituitary system. Anti-Müerian hormone (AMH) and Stem cell factor (SCF) proved to be the key factors in follicle recruitment and development. The balance between AMH and SCF was tightly related to ovarian reserve. To investigate the intraovarian effect of GnRH-a or GnRH-ant on ovarian reserve, we examined AMH and SCF expression in human granulosa cells (hGCs). GCs were isolated from follicular aspirates after oocyte removal from the patients undergoing assisted reproduction techniques. After pretreated with GnRH-a (triptorelin) or GnRH-ant (cetrorelix) for 48 h, mRNA and protein of AMH and SCF were analyzed by Real-time PCR and Immunoblot assay respectively. The results indicated that AMH mRNA and protein expressions were down-regulated in the GnRH-ant groups, SCF mRNA and protein expressions were up-regulated in the high-dose GnRH-ant group. There was no difference of AMH and SCF expression in the GnRH-a group or GnRH-a + GnRH-ant group compared with control. These results suggested the effects of GnRH-a and GnRH-ant on the regulation of AMH and SCF were different, which may provide insight into the mechanism of GnRH-a and GnRH-ant interventions on ovarian reserve.

Clinical and metabolic features of polycystic ovary syndrome among Chinese adolescents.

OBJECTIVES: To explore the clinical and metabolic features exhibited by Chinese adolescents with polycystic ovary syndrome (PCOS) and to determine the differences between nonobese and obese adolescent patients with PCOS. DESIGN: Clinical cross-sectional study. SETTING: Department of Gynecology and Reproductive Center. PARTICIPANTS: 25 obese and 66 nonobese adolescents with PCOS and 26 age-matched controls. INTERVENTIONS: Fasting venous blood samples and an oral glucose tolerance test using 75 g of glucose were obtained from PCOS patients and controls. MAIN OUTCOME MEASURES: Clinical features were summarized. Serum levels of FSH, LH, E(2), TT, SHBG, fasting insulin, and fasting glucose were measured. RESULTS: The prevalence of obesity in adolescents with PCOS was 27% (25/91). 99% of these patients presented with menstrual disorders, 84% presented with clinical and/or biochemical hyperandrogenism, and 90% exhibited an ultrasonographic appearance of polycystic ovaries. The prevalence of hirsutism and acanthosis nigricans were higher in the obese PCOS group than in the nonobese PCOS group (72% vs 41% and 44% vs 5%, respectively). A total of 5 of 20 obese (25%) and 5 of 36 nonobese patients (14%) demonstrated impaired glucose tolerance levels. CONCLUSIONS: Chinese adolescents with PCOS manifest clinical and metabolic features similar to those of adult Chinese women with PCOS except for the increased prevalence of hyperandrogenism and insulin resistance. Adolescents with high risk factors, especially those with menstrual disorders and hyperandrogenism, may need careful clinical screening.

Regulation of gonadotropin-releasing hormone (GnRH) receptor-I expression in the pituitary and ovary by a GnRH agonist and antagonist.

The aim of the current study was to examine the effects of gonadotropin-releasing hormone agonist (GnRH-a) and antagonist (GnRH-ant) on the expression of GnRH receptor-I (GnRHR-I) in pituitary and ovaries in cyclophosphamide (CTX) chemotherapeutic rats and to investigate the possible mechanism of interventions of GnRH-a and GnRH-ant in CTX-induced ovarian damage. In total, 36 female rats were distributed into 6 groups at random: normal saline (NS) group, CTX group, GnRH-a + NS group, GnRH-a + CTX group, GnRH-ant + NS group, and GnRH-ant + CTX group. After the rats were killed, the expression of GnRHR-I messenger RNAs (mRNAs) and proteins in pituitary and ovaries were examined by reverse transcriptase polymerase chain reaction (RT-PCR) and Western blot, respectively. The distribution of GnRHR-I in various compartments of the ovaries was observed by immunohistochemistry. Significant downregulation of GnRHR-I mRNA and protein expression in the pituitary were observed after treatment with GnRH-a or GnRH-ant. Moreover, GnRH-ant was more potent for this direct and fast inhibition. In ovary, GnRHR-I expression was significantly downregulated by GnRH-a. Although GnRH-ant slightly decreased the ovarian expression of GnRHR-I mRNA, the protein level was only weakly changed. In the ovarian compartment, GnRHR-ant groups had markedly GnRHR-I expression in early and late growing follicles compared to GnRHR-a groups that exhibited decreased expression of GnRHR-I, especially in late growing follicles. In summary, this study presents evidence for the different regulating effects of GnRH-a and GnRH-ant on the expression of GnRHR-I in pituitary and ovaries, which may provide insight into the mechanism of GnRH-a and GnRH-ant interventions on chemotoxic ovarian damage.