Initiation of growth of resting ovarian follicles is a key phenomenon for providing an adequate number of mature oocytes in each ovulation, while preventing premature exhaustion of primordial follicle reserve during the reproductive lifespan. Resting follicle dynamics strongly suggest that primordial follicles are under constant inhibitory influences, by mechanisms and factors whose nature rema...

The regulatory mechanisms of early follicle development are not clearly understood. Although relaxin is a peptide that controls cell proliferation and differentiation in many tissues, its role in human follicular development is unclear. In this study we cultured slices of human ovarian cortical tissue in the presence and absence of recombinant human relaxin. Ovarian tissue was obtained by biops...

Ovarian reserve depends on the number of primordial follicles in the ovarian cortex. It was suggested that determining the follicular density directly by obtaining ovarian biopsy might be more accurate than current indirect biochemical and ultrasonic tests, especially for women in the later stage of their reproductive life. It might also be important and beneficial for young patients having che...

The cytologic localization and cellular levels of insulin receptors in the human ovary during follicular growth, regression and atresia were examined by the avidin/biotin immunoperoxidase techniques with a monoclonal antibody to insulin receptor. In primordial follicles, only the oocyte showed a weak immunostaining for insulin receptor, whereas the stromal cells surrounding primordial follicles...

BACKGROUND Ovarian cryopreservation is one option for fertility preservation in patients with cancer. The danger of reseeding malignancies could be eliminated by in vitro maturation of primordial follicles from the frozen-thawed tissue. However, the development of this system is hindered by uncertainties regarding factors that activate primordial follicles. Neuronal growth factors such as vasoa...

Many young cancer patients are now being given the option to store ovarian cortical biopsies before undergoing potentially damaging chemo- or radiotherapy. This tissue mainly contains large numbers of immature primordial follicles. Currently the only option to restore fertility using this tissue is by transplantation which may not be a viable option for all patients. Greater options to realise ...

BACKGROUND Anti-Müllerian hormone (AMH) inhibits the initiation of the development and early growth of mouse ovarian follicles. Furthermore, the ovarian follicle pool diminishes prematurely in AMH-knockout mice. In this study, we examined whether AMH plays a similar role in humans, controlling ovarian follicle growth. METHODS Human ovarian cortical tissue biopsy specimens were cut into small ...

A system of 16 non-linear, delay differential equations with 66 parameters is developed to model hormonal regulation of the menstrual cycle of a woman from age 20 to 51. This mechanistic model predicts changes in follicle numbers and reproductive hormones that naturally occur over that time span. In particular, the model illustrates the decline in the pool of primordial follicles from age 20 to...

A network of extracellular signaling factors has previously been shown to act in concert to control the ovarian primordial to primary follicle transition. The current study was designed to investigate the roles of the endogenous bone morphogenetic protein (BMP) inhibitors Gremlin 1 (GREM1) and GREM2 in primordial follicle transition in the rat ovary. GREM1 and GREM2 treatments were found to rev...

Histological studies have demonstrated that polycystic ovaries (PCO) contain increased numbers of preantral follicles with a specific increase in primary follicles. Polycystic ovary syndrome is associated with hyperandrogenism and pre- and postnatal androgenization of primates increases the pool of growing follicles producing changes resembling PCO. In vitro studies could test the hypothesis th...