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...

During each ovarian cycle, only a definite number of follicles ovulate, while the others undergo a degeneration process called atresia. We have designed a multi-scale mathematical model where ovulation and atresia result from a hormonal controlled selection process. A 2D-conservation law describes the age and maturity structuration of the follicular cell population. In this paper, we focus on t...

During follicular atresia in the sheep and pig there is a marked reduction in the vasculature of the theca interna underlying the membrana granulosa. In the sheep there is no reduction of thecal blood vessels adjacent to the cumulus which remains viable. By contrast, in the pig the cumulus degenerates during atresia and the underlying thecal vasculature is greatly diminished. However, despite l...

Abstract Skipped spawning, or variation in spawning periodicity, occurs many annual fish species and is an important consideration for population management. We assessed plasma sex steroid concentrations measured gonad size ovarian follicle diameter as metrics to nonlethally identify mass follicular atresia, which may contribute skipped Burbot Lota lota. maintained wild captivity exposed them i...

The ovary receives a finite pool of follicles during fetal life. Atresia remains the major form of follicular expenditure at all stages since development of ovary. The follicular reserve, however, declines at an exponential rate leading to accelerated rate of decay during the years preceding menopause. We examined if diminished follicle reserve that characterizes ovarian aging impacts the attri...

Most follicles in the mammalian ovary undergo atresia. Granulosa cell apoptosis is a hallmark of follicle atresia. Our previous study using a microRNA (miRNA) microarray showed that the let-7 microRNA family was differentially expressed during follicular atresia. However, whether the let-7 miRNA family members are related to porcine (Sus scrofa) ovary follicular apoptosis is unclear. In the cur...

The apoptosis of granulosa cells is involved in follicular atresia and degeneration of the corpus luteum. The mechanisms that regulate follicular atresia and luteal degeneration remain obscure. Survivin is a member of the family of inhibitors of apoptosis protein that is expressed during fetal development and in cancer tissues. The present study investigates the expression of survivin, as well ...

Ovarian stimulation is usually carried out with exogenous gonadotropins to induce multiple follicle development and to mature more oocytes for in vitro Fertilization (IVF) [1]. According to the traditional folliculogenesis, antral follicles in each ovary are recruited from the late luteal phase of the preceding menstrual cycle for the following follicle phase. The dominant follicle is selected ...

The physiological regulation of follicular atresia was investigated during the early luteal phase after ovulation and during altrenogest-synchronized preovulatory maturation in pigs (gilts). Apoptosis in dispersed granulosa cells was determined by flow cytometry. Apoptotic (A0) cells contain low, subdiploid amounts of DNA fluorescence. Follicles were classified biochemically as atretic or nonat...