The present study was undertaken to explore the regulatory mechanisms for meiotic resumption of pig cumulus-oocyte complexes (COCs) by assessing the nuclear status of oocytes, the degree of gap junction cell-to-cell communication and cumulus expansion after culture of various numbers of COCs in 10 microl droplets of medium for 24 h. Gap junction communication was examined by confocal laser scan...

Few studies demonstrate at a biochemical level the metabolic profile of both cumulus cells and the oocyte during maturation. The aim of the present study was to investigate the differential participation of enzymatic activity in cumulus cells and in the oocyte during in vitro maturation (IVM) by studying the activity of enzymes involved in the control of amino acid metabolism, alanine aminotran...

Cumulus-oocyte complexes were aspirated from small antral follicles (3-5 mm in diameter) and divided into 2 groups: complexes in which a dark rim of corona cells were visible around the zona pellucida (group 1); and those in which the corona displayed the same density as the rest of the cumulus cell mass (group 2). Cumulus complexes of both groups were evaluated by acetoorcein staining, scannin...

Porcine cumulus oocyte complexes (COCs) were cultured together in 10-microliters droplets of culture medium. When 10 COCs were cultured for 24 h, germinal vesicle breakdown (GVBD) occurred in 81% of them. When more COCs (20 or 40) were put into the same volume of medium the frequency of GVBD gradually decreased. This inhibition was not observed in denuded oocytes. The process of GVBD was advers...

OBJECTIVE This study examines the effects of hydrostatic pressure on in vitro maturation (IVM) of oocytes derived from in vitro grown follicles. MATERIALS AND METHODS In this experimental study, preantral follicles were isolated from 12-day-old female NMRI mice. Each follicle was cultured individually in Alpha Minimal Essential Medium (α-MEM) under mineral oil for 12 days. Then, follicles wer...

This study assessed the participation of amphiregulin (AREG) and bone morphogenetic protein 15 (BMP15) during maturation of bovine cumulus-oocyte complexes (COCs) on cumulus cell function and their impact on subsequent embryo development. AREG treatment of COCs enhanced blastocyst formation and quality only when in the presence of BMP15. Expression of hyaluronan synthase 2 was enhanced by folli...

BACKGROUND: The purpose of this study was to localize the expression of steroid sulfatase (STS) in cumulus cells and to determine the relationship between STS mRNA expression and the serum levels of follicle-stimulating hormone (FSH), luteinizing hormone (LH), estradiol and progesterone. METHODS: The subject group included 49 women (29 to 44 years old) for whom in vitro fertilization treatment ...

this study was designed to examine the effects of retinoic acid adding to cumulus and/or fibroblast cellsmonolayer on the development of mouse early embryos. one-cell mouse embryos were obtained from nmrimice after superovulation by an intraperitoneal injection of 5 iu equine chorionic gonadotrophin (ecg)followed 48 hrs later by 5 iu human chorionic gonadotrophin (hcg). mouse embryonic fibrobla...

An age-dependent acceleration of apoptosis occurs in female germ cells (oocytes), and this requires communication between the oocyte and its surrounding somatic (cumulus) cells. Here we show in aged mice that ceramide is translocated from cumulus cells into the adjacent oocyte and induces germ cell apoptosis that can be prevented by sphingosine-1-phosphate. Trafficking of ceramide requires gap ...

The role of alkaloids in cigarette smoke was investigated in the cumulus expansion of oocyte-cumulus complexes (OCC) isolated from large antral porcine follicles. Suppression of the cumulus expansion stimulated by FSH was observed in the presence of different concentration of cadmium, anabasine and nicotine but not its metabolite cotinine. There were comparable inhibitory effects of cadmium and...