Background: Cryopreservation of oocytes, which is an interesting procedure to conserve female gametes, is an essential part of reproductive biotechnology. The objective of the present study was to investigate the effects of cumulus cells on survival,in vitro maturation,fertilization and subsequent developmental capacity of mouse germinal vesicle stage oocytes during vitrification. Materials and...

background: the mitogen-activated protein kinase (mapk) pathway is one of the major signaling pathways that transmit intracellular signals initiated by extracellular stimuli to the nucleus. the stress-activated protein kinase (sapk)/c-jun nh2-terminal kinase is a subfamily of map kinases implicated in cytokine and stress responses. objective: in this study, we have examined total and phosphoryl...

Background: Cryopreservation of ovaries is an important technique in assisted reproduction technology. Physical forces like hydrostatic pressure have a pivotal role in reproduction systems. Due to changes in intrafollicular pressure during ovulatory process, this study designed to examine the effects of hydrostatic pressure on oocyte maturation and cell death in cumulus cells from cryopreserved...

background: in vitro maturation (ivm) of oocytes is a promising technique to reduce the costs and avert the side-effects of gonadotropin stimulation for in vitro fertilization (ivf). the pregnancy rates from oocytes matured in vitro are much lower than those of in vivo stimulation cycles, indicating that optimization of ivm remains a challenge. objective: in this study, we investigated the effe...

Oocyte-derived bone morphogenetic protein 15 (BMP15) and growth differentiation factor 9 (GDF9) are key regulators of follicular development. Here we show that these factors control cumulus cell metabolism, particularly glycolysis and cholesterol biosynthesis before the preovulatory surge of luteinizing hormone. Transcripts encoding enzymes for cholesterol biosynthesis were downregulated in bot...

Background: Most studies show that 9 to 24% of people who are in in vitro fertilization (IVF) cycles are women who respond poorly to ovarian stimulation. Women with poor ovarian response (POR) are a group of infertile patients whose ovarian reserve, ovarian response to medication, and the quality of ovum are declining. Therefore, the number of female cycles, the number of fetuses from the oocyt...

Cell-to-cell communication was characterized in cumulus-oocyte complexes from rat ovarian follicles before and after ovulation. Numerous, small gap junctional contacts were present between cumulus cells and oocytes before ovulation. The gap junction are formed on the oocyte surface by cumulus cell processes that transverse the zona pellucida and contact the oolemma. The entire cumulus mass was ...

Background: In vitro maturation is a good method to decrease cancer risk of superovulation by gonadotropin hormones. A paracrine effect of oocyte secretions on oocyte developmental competence is under investigation. Apart from oocyte maturation, ovulation in vivo requires a precise control of extracellular matrix modification. Cumulus cells secrete hyaluronan to form a muco-elastic extracellula...