Effect of lanosterol on the in vitro maturation in semi-defined culture system of prepubertal ewe oocytes

Zygote ◽  
2011 ◽  
Vol 22 (1) ◽  
pp. 50-57 ◽  
Author(s):  
F. Marco-Jiménez ◽  
J.S. Vicente ◽  
M.P. Viudes-de-Castro

SummaryThe choice of medium and supplements can affect meiotic regulation and may have an impact on the regulation of mammalian oocyte growth and embryonic cell function. The aim of the present study was to assess the effects of oxygen concentration and endogenous lanosterol on the in vitro maturation (IVM) media without serum and based on recombinant human chorionic gonadotrophin in prepubertal ewe oocytes. Firstly, the effect of varying oxygen concentrations (5% and 20%) during IVM in TCM-199 supplemented (4 mg/ml bovine serum albumin (BSA), 100 μM cysteamine, 0.3 mM sodium pyruvate, 0.1 UI/ml recombinant follicle-stimulating hormone (r-FSH; Gonal-F® 75 UI, Serono, Italy), 0.1 UI/ml recombinant leuteinizing hormone (r-LH; Lhadi® 75 UI, Serono, Italy) and 1 μg/ml estradiol-17β) on subsequent nuclear maturation of oocytes examined under ultraviolet light following staining with bisbenzimide (Hoechst 33342) was investigated. Secondly, two concentrations of lanosterol (0, 10 and 50 μM) were added to the IVM medium. Nuclear maturation of oocytes was examined as previously. Lipid content in oocytes, an important indicator of cytoplasmic maturity, was also measured using Nile red fluorescent stain. The results showed that low oxygen concentration affected the nuclear maturation. Similarly, a significantly higher rate of meiosis resumption was observed with 10 μM (72.3%) of lanosterol compared with the control (51.8%) or 50 μM of lanosterol (59.4%). A significantly higher content of lipids was also observed with 10 and 50 μM of lanosterol (7.3 ± 0.2 × 106 and 7.4 ± 0.2 × 106 arbitrary units of fluorescence) compared with the control (6.7 ± 0.2 × 106 arbitrary units of fluorescence). The results indicate that 10 μM lanosterol during IVM in medium without serum and based on recombinant human chorionic gonadotrophin has a positive effect on maturation of prepubertal ewe oocytes.

2007 ◽  
Vol 19 (1) ◽  
pp. 288
Author(s):  
M.-K. Kim ◽  
H.-J. Oh ◽  
Y. H. Fibrianto ◽  
G. Jang ◽  
H.-J. Kim ◽  
...  

Growth, maturation, and ovulation of the Graafian follicle depend on appropriate patterns of secretion, sufficient concentrations, and adequate ratios of various reproductive hormones, especially follicle stimulating hormone (FSH) and luteinizing hormone (LH) (Van Tol et al. 1996 Mol. Reprod. Dev. 45, 218–224). The present study investigated the effects of FSH and human chorionic gonadotrophin (hCG) on the nuclear maturation of canine oocytes. In addition, in order to investigate the effect of stage of the estrous cycle on the meiotic competence of canine oocytes matured in vitro, oocytes were collected from various reproductive states and matured in vitro in the presence of the gonadotrophins. Estrous cycle stage was evaluated for each bitch by ovarian morphology, and bitches were categorized according to the stage of the estrous cycle (anestrus, follicular, or diestrus) prior to oocyte collection. Recovered oocytes were cultured in serum-free tissue culture medium (TCM)-199 supplemented with various concentrations of FSH (Exp. 1: 0, 0.1, 1.0, or 10 IU) or hCG (Exp. 2: 0, 0.5, 1.0, or 10 IU) or both (Exp. 3: 1 IU FSH + 1 IU hCG) for 72 h to determine the effective concentration of these hormones, and to examine their combined effect. After maturation culture, oocytes were denuded in PBS containing 0.1% (w/v) hyaluronidase by gentle pipetting. The denuded oocytes were stained with Hoechst 33342 in glycerol and the nuclear state of oocytes was evaluated under UV light. The rates of maturation to the MII stage were significantly higher (P < 0.05) when follicular-stage oocytes were supplemented with 1 IU FSH (6.2%) compared with the other FSH-supplemented groups (0.0 to 3.3%) or to the control (1.8%), or 0.1 or 10.0 IU FSH (0 to 1.2%). Significantly higher (P < 0.05) maturation rate to MII stage was observed in follicular-stage oocytes supplemented with 1.0 IU hCG (7.2%) compared with the control or other hCG-supplemented groups (0 to 1.5%). However, FSH and hCG together did not improve the nuclear maturation rate of canine oocytes (2.4%) compared with FSH (6.2%) and hCG alone (7.2%). In conclusion, FSH or hCG alone significantly increased the maturation of canine oocytes to the MII stage. This work was supported by grant No. M1062503005-06N250300510 from KOSEF, Republic of Korea.


1981 ◽  
Vol 91 (2) ◽  
pp. 197-203 ◽  
Author(s):  
M. C. RICHARDSON ◽  
G. M. MASSON

Cell suspensions were prepared from tissue samples of human corpora lutea obtained during the mid- and late-luteal phase of the menstrual cycle. Both oestradiol and progesterone production by dispersed cells were stimulated by similar concentrations of human chorionic gonadotrophin (hCG). As the degree of stimulation of production by hCG was greater for progesterone than for oestradiol (five- to tenfold compared with two- to threefold higher than basal production), the ratio of progesterone to oestradiol produced varied according to the level of trophic stimulation. A comparison of cell suspensions prepared from mid- and late-luteal phase corpora lutea, exposed to the same concentration of hCG (10 i.u./ml) in vitro, did not reveal a shift to oestradiol production in the late-luteal phase. Provision of additional testosterone during incubation raised the level of oestradiol production by dispersed luteal cells. At an optimum concentration of testosterone (1 μmol/l), oestradiol synthesis was not raised further in the presence of hCG or N6, O2-dibutyryl cyclic AMP, suggesting a lack of induction or activation of the aromatase system by gonadotrophin in short-term cultures. Basal and stimulated levels of progesterone production were not significantly impaired in the presence of testosterone.


2020 ◽  
Author(s):  
Yu Liu ◽  
Jing Li ◽  
Yihong Guo

Abstract BackgroundOestradiol, an important hormone in follicular development and endometrial receptivity, is closely related to clinical outcomes of fresh in vitro fertilization-embryo transfer (IVF-ET) cycles. A supraphysiologic E2 level is inevitable during controlled ovarian hyper-stimulation (COH), and its effect on the outcome of IVF-ET is controversial. The aim of this retrospective study is to evaluate the association between elevated serum oestradiol (E2) levels on the day of human chorionic gonadotrophin (hCG) administration and neonatal birthweight after IVF-ET cycles.MethodsThe data of 3659 infertile patients with fresh IVF-ET cycles were analysed retrospectively between August 2009 and February 2017 in First Hospital of Zhengzhou University. Patients were categorized by serum E2 levels on the day of hCG administration into six groups: group 1 (serum E2 levels≤1000 pg/mL, n=230), group 2 (serum E2 levels between 1001 and 2000 pg/mL, n=524), group 3 (serum E2 levels between 2001 and 3000 pg/mL, n=783), group 4 (serum E2 levels between 3001 and 4000 pg/mL, n = 721), group 5 (serum E2 levels between 4001 and 5000 pg/mL, n=548 ), and group 6 (serum E2 levels > 5000 pg/mL, n=852). Univariate linear regression was used to evaluate the independent correlation between each factor and outcome index. Multiple logistic regression was used to adjust for confounding factors.ResultsThe LBW rates were as follows: 3.0% (group 1), 2.9% (group 2), 1.9% (group 3), 2.9% (group 4), and 2.0% (group 6) (P =0.629), respectively. There were no statistically significant differences in the incidences of neonatal LBW among the six groups. We did not detect an association between peak serum E2 level during ovarian stimulation and neonatal birthweight after IVF-ET.ConclusionThe results of this retrospective cohort study showed that serum E2 peak levels during ovarian stimulation were not associated with birth weight during IVF cycles. In addition, no association was found between higher E2 levels and increased LBW risk. Our observations suggest that the hyper-oestrogenic milieu during COS does not seem to have adverse effects on the birthweight of offspring after IVF.


1978 ◽  
Vol 89 (3) ◽  
pp. 492-505 ◽  
Author(s):  
D. M. Robertson ◽  
H. Suginami ◽  
H. Hernandez Montes ◽  
C. P. Puri ◽  
S. K. Choi ◽  
...  

ABSTRACT The presence of an hCG-like material in urinary and pituitary extracts and plasma obtained from non-pregnant subjects was investigated. Two assay methods were used to detect this material following fractionation of pituitary and urinary extracts by gel filtration (Ultrogel AcA 54) and/or isoelectrofocusing: a) a radioimmunoassay employing an antiserum raised against a specific sequence of the carboxy terminal region (residues 115– 145) of the β-subunit of hCG, and b) an in vitro bioassay method which measures both hLH and hCG activities. The fractionation procedures employed provide a satisfactory separation of highly purified hCG and hLH preparations. In the pituitary and urinary extracts hCGβ-peptide-like immunoactive (PIA) material was found consistently, which co-eluted with iodinated hCG following gel filtration and possessed pI values similar to those of hCG when subjected to isoelectrofocusing. The PIA material also exhibited in vitro biological activity similar to that shown by hLH and hCG. Detectable levels of immunoactive material were also found in plasma; however, the plasma levels of this PIA material were not influenced by classical endocrine measures such as the stimulation or inhibition of gonadotrophin secretion. The low levels of this material in plasma precluded its further characterization by gel filtration or electrofocusing. Whereas the present data and those reported by other investigators seem to suggest the presence of some hCG-like material in urinary and pituitary extracts and possibly in plasma of non-pregnant subjects, it is emphasized that the available evidence is not sufficiently conclusive to exclude other interpretations as to the nature of this material.


1989 ◽  
Vol 2 (2) ◽  
pp. 107-112 ◽  
Author(s):  
R. K. Iles ◽  
T. Chard

ABSTRACT Material with the immunochemical characteristics of human chorionic gonadotrophin (hCG) is produced by bladder tumour cells in vitro and in vivo. In order to characterize this material further, media were collected from 17 cell cultures (three choriocarcinomas, seven bladder carcinomas and seven 'normal' urothelium). The hCG-like material was compared with pregnancy hCG and purified α- and β-subunits by specific radioimmunoassays. Media were also submitted to affinity chromatography and the fractions further analysed by SDS-PAGE and Western blotting. It was shown that both the neoplastic and normal urothelium produced only free β-subunit-like material. This urothelial 'β-hCG' has the same molecular weight and electrophoretic mobility as that present in the intact hCG of pregnancy.


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