When Ca2+ is released from internal stores in living cells, the resulting wave of increased concentration can travel without deformation (continuous propagation) or with burst-like behavior (saltatory propagation). We analyze the "fire-diffuse-fire" model in order to illuminate the differences between these two modes of propagation. We show that the Ca2+ release wave in immature Xenopus oocytes...

Objective The objective of this study was to evaluate LH/FSH and demographic variables on maturation stage of oocytes in patients with polycystic ovary syndrome (PCOS) with or without insulin resistance. MaterialsAndMethods Sixty patients with IVF/ICSI indication were subdivided into 3 groups as follow: 20 subjects were assigned to control (fertile women with male infertility history) group, 20...

  Background & Aim: Considering that antioxidants are known as effective free radicals scavenger, it may be able to improve the in vitro oocyte maturation and the fetal quality. This study was designed to determine the effect of Gundelia tournefortii leaves (GTE) hydro-alcoholic extract as a source of antioxidant on in vitro oocyte maturation. Experimental: Germinal vasicle (GV) were...

Background: In vitro maturation (IVM) of immature oocyte is a promising treatment option for infertile women.IVM procedures attempt to mimic the natural conditions of the follicular environment. The technique of IVM of oocytes has been successful after the first trial using culture of human oocytes in follicular fluid. The crucial part of this technique is the maturation process itself, and the...

Currently, it is believed that toad oocyte maturation is dependent on the physiological conditions of winter hibernation. Previous antibody-blocking experiments have demonstrated that toad ubiquitin carboxyl-terminal hydrolase L1 (tUCHL1) is necessary for germinal vesicle breakdown during toad oocyte maturation. In this paper, we first supply evidence that tUCHL1 is highly evolutionarily conser...

BACKGROUND The LH surge promotes ovulation via activation of multiple signaling networks in the ovarian follicle. Studies in animal models have shown the importance of LH-induced activation of the epidermal growth factor (EGF)signaling network in critical peri-ovulatory events. We investigated the biological significance of regulatory mechanisms mediated by EGF-like growth factors during LH sti...

Information about the mechanisms of meiotic arrest and resumption of meiosis in feline oocytes is still limited. The aim of this study was to investigate the effect of the presence of gonadotropins during IVM, on meiotic progression in relation to the status of gap junction mediated communications between oocyte and cumulus cells, to the cAMP intracellular content, and to the intra-oocyte conce...

background: leukemia inhibitory factor (lif) is a 45-56 kda glycoprotein that has an important role in proliferation and embryo implantation. its effect on oocyte maturation and how to exert the function remained to be elucidated. methods: immature mice superovulated with human menopausal gonadotropin and germinal vesicle (gv) oocytes were obtained from ovary 48 hours after. gv oocytes were cul...

The aim of the present study was to find the effects of pre and post vitrification taxol treatment on bovineimmature cumulus oocyte complexes (COCs). Bovine ovaries were collected from the local slaughterhousein a container with 30-37°C physiologic saline and supplemented with antibiotics. The grade A aspiratedCOCs were assigned to 6 experimental groups; The 1st group was control (n=100) in whi...

  Background & Aim: Considering that antioxidants are known as effective free radicals scavenger, it may be able to improve the in vitro oocyte maturation and the fetal quality. This study was designed to determine the effect of Gundelia tournefortii leaves (GTE) hydro-alcoholic extract as a source of antioxidant on in vitro oocyte maturation. Experimental: Germinal vasicle (GV) were...