In vitro bioassay for human chorionic gonadotrophin

1980 ◽  
Vol 93 (1) ◽  
pp. 114-122 ◽  
Author(s):  
T. Rabe ◽  
U. Hilgenfeldt ◽  
W. E. Merz
Keyword(s):  
Dose Response ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Lag Phase ◽  
In Vitro Tests ◽  
Intracellular Camp ◽  
In Vitro Bioassay ◽  
Assay Sensitivity ◽  
Inter Assay Variation

Abstract. The adenylate cyclase stimulation (ACS) assay is a new in vitro bioassay for human chorionic gonadotrophin (hCG) which is based on the hCG-induced accumulation of cAMP in the incubation medium of decapsulated rat testes. The detection limit for hCG is 0.7 mIU/ml (P < 0.05). A linear dose-response curve on semilogarithmic plots was obtained using 0.18, 0.45, and 1.125 IU hCG/ml. The precision of the ACS assay was satisfactory (λ-value: 0.20 + 0.02, mean ± sd), n = 14). Intra-assay variation: 15% and inter-assay variation: 20%. Medium cAMP was determined by means of a bovine adrenal protein binding assay. Sensitivity: 0.2 pmoles cAMP/ml. Range: 2 to 40 pmoles/ml. Intra-assay variations: 5% and inter-assay variation: 8%. As pre-conditions for the ACS assay, cAMP kinetics and dose-response curves were investigated. In kinetic studies of cAMP production the lag phase between hormone addition and increase of medium cAMP is shortened with higher hCG concentration. The highest concentration of cAMP was measured after an incubation of 3 h. Thereafter the concentration declines exponentially due to a decrease of intracellular cAMP formation and pre-dominating activity of extracellular phosphodiesterase. A prolongation of cAMP half-life from 16.8 min to 218 min was obtained by the addition of theophylline (70 mm). Pre-treatment of rats with 50 IU sc 48 and 24 h prior to in vitro tests caused a complete inhibition of cAMP response to hCG stimulation. Four weeks after this desensitization, the sensitivity of the testes had recovered to 80%.

STIMULATION BY HUMAN CHORIONIC GONADOTROPHIN OF OESTRADIOL PRODUCTION BY DISPERSED CELLS FROM HUMAN CORPUS LUTEUM: COMPARISON WITH PROGESTERONE PRODUCTION; UTILIZATION OF EXOGENOUS TESTOSTERONE

1981 ◽  
Vol 91 (2) ◽  
pp. 197-203 ◽  
Author(s):  
M. C. RICHARDSON ◽  
G. M. MASSON
Keyword(s):  
Luteal Phase ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Cell Suspensions ◽  
Corpora Lutea ◽  
Progesterone Production ◽  
Late Luteal Phase ◽  
Oestradiol Production ◽  
Dispersed Cells

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.

Varying dose–response characteristics of different immunoassays and an in-vitro bioassay for FSH are responsible for changing ratios of biologically active to immunologically active FSH

1990 ◽  
Vol 127 (3) ◽  
pp. 523-532 ◽  
Author(s):  
F. Jockenhövel ◽  
S. A. Khan ◽  
E. Nieschlag
Keyword(s):  
Sertoli Cell ◽  
Dose Response ◽  
Serum Levels ◽  
Biologically Active ◽  
Testicular Function ◽  
In Vitro Bioassay ◽  
Great Caution ◽  
Response Characteristics ◽  
Infertile Men

ABSTRACT Serum FSH levels in fertile and infertile men were determined by applying the Sertoli cell in-vitro bioassay and six different immunoassays. Bioassay and immunoassay estimates were significantly correlated (r ranging from 0·78 to 0·86; P<0·01). On average, all immunoassays measured lower FSH concentrations in samples with low FSH levels and higher FSH concentrations in those with high FSH levels compared with the bioassay. Ratios of bioactivity to immunoreactivity (B/I) were highest in fertile men and lowest in men with severe disturbances of testicular function. Depending on which immunoassay was used these differences were either significant or only marginal. Dose–response characteristics for WHO FSH standard preparation 78/549, used in the bioassay as well as in the immunoassays, were different between immunoassays and the bioassay, suggesting that decreasing B/I ratios with increasing FSH serum levels were method-related and reflected different slopes of the dose–response characteristics of the assays, rather than being true changes in the molecular composition of FSH. The present investigation underlines the necessity of choosing the immunoassay used for comparison with the bioassay carefully and of validating the system in regard to parallelism between dose–response characteristics. B/I ratios must be interpreted with great caution and previous studies which report changing B/I ratios in various endocrine situations may have to be reevaluated. Journal of Endocrinology (1990) 127, 523–532

scholarly journals Association Between Serum Oestradiol Level on the Human Chorionic Gonadotrophin Administration Day and Neonatal Birthweight After in Vitro Fertilization-embryo Transfer: A Retrospective Study of 3659 Singleton Live Births

2020 ◽  
Author(s):  
Yu Liu ◽  
Jing Li ◽  
Yihong Guo
Keyword(s):  
Retrospective Study ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Vitro Fertilization ◽  
Group 4 ◽  
Group 3 ◽  
Group 2 ◽  
Ivf Et ◽  
Group 1

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.

STUDIES ON A HUMAN CHORIONIC GONADOTROPHIN-LIKE MATERIAL PRESENT IN NON-PREGNANT SUBJECTS

1978 ◽  
Vol 89 (3) ◽  
pp. 492-505 ◽  
Author(s):  
D. M. Robertson ◽  
H. Suginami ◽  
H. Hernandez Montes ◽  
C. P. Puri ◽  
S. K. Choi ◽  
...  
Keyword(s):  
Gel Filtration ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Specific Sequence ◽  
Gonadotrophin Secretion ◽  
Carboxy Terminal Region ◽  
Assay Methods ◽  
Low Levels ◽  
Carboxy Terminal

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.

Immunochemical analysis of the human chorionic gonadotrophin-like material secreted by 'normal' and neoplastic urothelial cells

1989 ◽  
Vol 2 (2) ◽  
pp. 107-112 ◽  
Author(s):  
R. K. Iles ◽  
T. Chard
Keyword(s):  
Bladder Tumour ◽  
Chorionic Gonadotrophin ◽  
Human Chorionic Gonadotrophin ◽  
Sds Page ◽  
Β Hcg ◽  
Bladder Carcinomas ◽  
Immunochemical Characteristics ◽  
Normal Urothelium

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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