Guoliang Xia

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Granulosa cells of mammalian Graafian follicles maintain oocytes in meiotic arrest, which prevents their precocious maturation. We show that mouse mural granulosa cells, which line the follicle wall, express natriuretic peptide precursor type C (Nppc) messenger RNA (mRNA), whereas cumulus cells surrounding oocytes express mRNA of the NPPC receptor NPR2, a(More)
Natriuretic peptide type C (NPPC) and its cognate receptor natriuretic peptide receptor 2 (NPR2) are essential for maintaining meiotic arrest in mouse oocytes residing in Graafian follicles. Cumulus cells, which are associated with the oocyte, express the receptor NPR2, a guanylyl cyclase, whereas mural granulosa cells express ligand NPPC. This study(More)
Fully grown mammalian oocytes are arrested at the first meiotic prophase until a surge of gonadotrophin at the mid-cycle. The actions of gonadotrophins, follicle stimulating hormone (FSH) and luteinizing hormone (LH), on oocyte meiotic resumption are believed to be mediated in large part through increasing the production of cyclic adenosine(More)
Locally synthesized atrial natriuretic peptide (ANP) and its receptors have been found in reproductive tissues of various mammals, and play an important role in the acrosome reaction of human sperm. The objective of the present study was to examine the expression of ANP and its receptors in pig spermatozoa and oviduct, and the effect of ANP on pig(More)
To investigate the relationship between the toxicity of puffer fish and the distribution of tetrodotoxin-producing bacteria in puffer fish Fugu rubripes collected from the Bohai Sea of China, bacteria were isolated from each organ (ovaries, livers, intestines and gallbladders) and screened for tetrodotoxin (TTX) production. 20 out of 36 isolated strains(More)
The present study is to investigate the immunolocalization of endothelial and inducible nitric oxide synthase (eNOS, iNOS) in porcine ovary and the effect of nitric oxide (NO) on antrum formation and oocyte meiotic resumption. In Experiment 1, preantral follicles (250-300 microm in diameter) were cultured in 0 (Control), 0.1, 0.3, 0.5 or 1 mM sodium(More)
Three puffer fishes, Fugu rubripes, collected from the Bohai Sea of China were examined for tetrodotoxin-producing microorganisms. An actinomycete isolated from the ovaries of the puffer fishes was found to produce tetrodotoxin. After being cultured at 28 degrees C for 7 days, cells were harvested by centrifuge and disrupted by ultrasonication. The toxin(More)
The present experiment used cultured mouse cumulus cell-enclosed oocytes (CEOs) and denuded oocytes (DOs) to study the function of nitric oxide (NO) in mouse oocyte meiotic maturation. Either positive or negative actions of NO on meiotic maturation has been observed when CEOs or DOs were cultured for 24 h in a medium containing 4 mM hypoxanthine (HX) to(More)
Mammalian oocytes within Graafian follicles are arrested at prophase I by factors from surrounding follicle cells, and resume meiosis after an LH surge from the pituitary. The maintenance of meiotic arrest requires high levels of cAMP, resulting from G-protein-coupled receptor (GPR) 3 and/or GPR12 activation of adenylyl cyclase within the oocyte. Recent(More)
It is proved that epidermal growth factor (EGF)-like factors mediate gonadotropin-induced rodent oocyte maturation via EGF receptor (EGFR). However, the detail kinetics and signal pathway between FSH and EGF/EGFR is not clear in large animals. In the present study, we investigated the roles of EGFR and protein kinase C (PKC) in FSH-induced porcine oocyte(More)