What is the difference between lh and hcg

Follicle-stimulating hormone and human spermatogenesis. J Clin Invest. Endocr Abstr. BioScientifica; Transformation of human granulosa cells with the E6 and E7 regions of human papillomavirus. Tyrosine sulfation is required for agonist recognition by glycoprotein hormone receptors. EMBO J. Structural differences in the hinge region of the glycoprotein hormone receptors: evidence from the sulfated tyrosine residues.

Differential binding affinities of rat testis luteinizing hormone LH receptors for human chorionic gonadotropin, human LH, and ovine LH. Shiraishi K, Ascoli M. Tai P, Ascoli M. Hirakawa T, Ascoli M. Galet C, Ascoli M. Cell Signal.

J Endocrinol. Extracellular signal-regulated kinases are involved in the acute activation of steroidogenesis in immature rat Leydig cells by human chorionic gonadotropin. J Biol Chem. Fetal but not adult Leydig cells are susceptible to adenoma formation in response to persistently high hCG level: a study on hCG overexpressing transgenic mice. Elevated steroidogenesis, defective reproductive organs, and infertility in transgenic male mice overexpressing human chorionic gonadotropin.

Consequences of genetic manipulations of gonadotrophins and gonadotrophin receptors in mice. Ann Endocrinol Paris. Narayan P. Targeted overexpression of luteinizing hormone in transgenic mice leads to infertility, polycystic ovaries, and ovarian tumors.

Download references. Not applicable. No datasets were generated by this study and all data are included in this published article. LR performed the experiments, data and statistical analysis and wrote the manuscript. FDP performed the experiments, contributed to data analysis and to manuscript writing. ST and TT provided immunoassay measurements and data analysis. MS performed experimental design, data interpretation and manuscript editing.

LC performed experimental design, performed the experiments, data interpretation, manuscript writing and editing. All authors read and approved the final manuscript. This work was performed under the permission of the local Animal Ethics Committee and current animal protection laws. Permission number: not applicable. Giardini , , Modena, Italy. Campi , , Modena, Italy. Orsola-Malpighi Hospital. Alma Mater University of Bologna, via G. Massarenti 9, I, Bologna, Italy. You can also search for this author in PubMed Google Scholar.

Correspondence to Livio Casarini. Total cAMP was measured after 3 h of incubation. TIF kb. In order to confirm the reliability of testosterone levels detected by immunoassay Fig. Testosterone levels detected by immunoassay Fig. DOC 92 kb. Reprints and Permissions. Riccetti, L. Human LH and hCG stimulate differently the early signalling pathways but result in equal testosterone synthesis in mouse Leydig cells in vitro.

Reprod Biol Endocrinol 15, 2 Download citation. Received : 23 September Accepted : 19 December Published : 05 January Anyone you share the following link with will be able to read this content:. Sorry, a shareable link is not currently available for this article. Provided by the Springer Nature SharedIt content-sharing initiative. Skip to main content. LH surges about 36 hours before ovulation is going to occur.

Of course, there are exceptions to almost every rule: some women, such as those with PCOS , may have hormone imbalances that can prevent ovulation. Contrary to popular belief, there are only a few days each month when a woman can successfully conceive. This is known as your fertile window , which includes the few days leading up to and day of ovulation. So, ovulation tests give you critical information about when to time intercourse. Intercourse is most likely to result in pregnancy during your fertile window, which includes the few days leading up to and day of ovulation.

Ovulation tests should be used during the first half of your cycle, leading up to your suspected ovulation date. We recommend beginning to test for ovulation about 18 days before your next period. However LH surges can be short, so as you get closer and closer to ovulation, you may want to test twice a day once in the morning, once in the evening to make sure you catch it!

You can now time intercourse accordingly! To be clear, ovulation tests are intended to be used to predict ovulation and help you time intercourse around peak fertility to allow for the best possible chance at conception. However, you may have heard about some women using their ovulation tests as a pregnancy test.

You may have heard that ovulation tests can be used to test for pregnancy. By Dr. Can ovulation tests detect the pregnancy hormone, HCG? The short answer is that ovulation tests can sort of act as a pregnancy test because LH is molecularly very similar to hCG. If you are pregnant, your hCG levels will be much higher than normal and an ovulation test may inaccurately detect this and read it as a high LH value. Louis, MO. For stable transfection we used the pTracer vector Invitrogen, Leek, The Netherlands , containing the cytomegalovirus promoter in front of the multiple cloning site and the green fluorescent protein reporter gene [18].

Human primary granulosa-lutein cells hGLC were isolated from ovarian follicles of women undergoing oocyte retrieval for assisted reproduction technologies ART. Before each experiment, granulosa cells were maintained in culture until day 6, to allow the recovery of the response to gonadotropins Fig.

Women undergoing ovarian stimulation for infertility due to tubal or male factor were included. Study approval was obtained from the local ethics committee and informed, written consent was obtained from each patient.

Comitato Etico Provinciale di Modena. The patients had to match the following criteria: absence of endocrine abnormalities; absence of severe viral or bacterial infections; age between 25—45 years. For cAMP stimulation a validated protocol was followed [27].

A total of 4 independent experiments were performed. To evaluate the kinetics of response to continuous exposure to gonadotropins, time-course experiments were performed. The intracellular cAMP was measured after each incubation. Cell viability was also evaluated [29].

A total of 3 independent experiments were performed. The quantitative detection of cAMP was performed in triplicate by a competitive ELISA kit and the data were entered into a curve fitting software which extrapolates the cAMP concentration against a standard curve. The data were represented using a log regression analysis.

Immunofluorescence analysis was performed to evaluate the kinetics of receptor internalization resulting from continuous in vitro stimulation of hGLC by gonadotropins. Negative and positive controls for the antibodies and non-permeabilized cells were also included. Negative controls were included in each step of the time-course experiment.

A total of 4 independent experiments were performed by using each time a different pool of granulosa cells obtained from 3—4 different patients. The signals were revealed by chemiluminescence, then acquired and semi-quantitatively evaluated by an image analysis system. Real-time PCR was performed in triplicates with the primers shown in Table 1. The ribosomal protein S7 RPS7 gene was used as normalizer.

A total of four experiments were performed. Each value obtained from hLH and hCG-stimulated cells was normalized for the corresponding control value. Mann Whitney's U -test, unpaired T-test or two-way analysis of variance were performed where appropriate. A significant difference in the kinetics of total cAMP production was found, with dose-response curves shifted significantly to the left in the case of hCG.

As shown in Fig. To assess this, a comparison between both type of gonadotropins was performed in different cell models Fig. The results obtained were similar, indicating that recombinant and extractive gonadotropins result in comparable effects on activation of signaling pathways, as otherwise well known from clinical practice.

Using equipotent doses, accumulation of intracellular cAMP by r-hLH resulted significantly faster, with maximal activation achieved in 10 minutes, while, by r-hCG, the same levels of maximal stimulation were attained only after 60 minutes of stimulation Fig.

Maximal intracellular cAMP accumulation was approximately 20—30 times higher than basal levels in untreated cells and was equally reached in both r-hLH- and r-hCG-stimulated cells, confirming that the ED 50 doses were indeed equipotent in acute activation.

S1 , as previously described for FSH as well [27]. Intracellular cAMP levels decreased after the first three hours but were not extinguished by min Fig. Moreover, cAMP concentrations during the peaks were often significantly higher upon r-hCG stimulation, in spite of the five-fold lower molar concentrations used, for the first 36 hours Fig. However, immunofluorescence staining revealed membrane localization of the LHCGR in unstimulated hGLC at each time-point, while the receptor was visible at the membrane after one hour of stimulation by r-hLH or r-hCG but prevalently intracellular after 15 and 24 hours, suggesting possible internalization Fig.

In addition, stimulated cells tended to assume a typical rounded shape with time, a phenomenon previously described in granulosa cells exposed to FSH [35]. Measurement of extracellular cAMP, released in culture medium.

One representative of three independent measurement is shown for each graph. Please notice the different progesterone scale on the Y axis on right side. Unstimulated cells control after 1 hour.

Unstimulated cells after 15 hours. Unstimulated cells after 24 hours. Cell-rounding in hLH-treated cells after 24 hours. The merging of the three images is in the lower right plate of each panel.

Images are from one experiment and are representative of three independent experiments with similar results. Western blot control for the anti-LHCGR antibody and non-permeabilized cells control for immunofluorescence staining were also included Fig. Interestingly, r-hLH appeared more effective than r-hCG at all doses tested.

Therefore, the maximally stimulating pM dose was used for both r-hLH and r-hCG in further experiments. The image is representative of 3 independent experiments. As shown for cAMP dose-response experiments Fig. The results obtained were similar, indicating that recombinant and extractive gonadotropins lead to essentially the same effects. Similar effects were observed for phospho-AKT. Here again r-hLH pM provoked a significant increase in phospho-AKT between 10 to 30 minutes, while the r-hCG pM stimulation appeared to be minimal and did not reach statistical significance at any time point Fig.

Comparison of phospho-AKT activation in hLH-stimulated vs unstimulated control at different time-points, by Western blotting image is representative of 4 independent experiments; total ERK as normalizer. Comparison of phospho-AKT activation in hCG-stimulated vs unstimulated control at different time-points, by Western blotting image is representative of 4 independent experiments; total ERK as normalizer.

Relative semi-quantification of the optical density representing phospho-AKT activation shown in figs. Conversely, neither U nor LY had any effect on r-hCG-inhibited NRG1 expression, suggesting that the early activation of these pathways is not involved in r-hCG-mediated action on neuregulin 1, a result consistent with the very weak or lacking activation of these pathways by r-hCG as demonstrated in Fig. We systematically analyzed whether hLH and hCG are equivalent in vitro in terms of biopotency, kinetics of response and molecular effects.

It is traditionally believed that hLH and hCG are biologically equivalent since they act via the same receptor, for which both molecules are assumed to have the same binding affinity. However, hLH and not hCG is the physiological hormone in non-pregnant women and the evolutionary reason for the presence of hCG in primates has not been clearly established. Our experiments challenge the concept that hLH and hCG have the same biopotency and bioactivity.

Our results demonstrate that, in vitro , in the presence of a standardized receptor milieau and at maximal stimulation, hCG is about 5-times more biopotent than equimolar concentrations of hLH in terms of cAMP production. Whether the rate of cAMP increase depends on the levels of receptor occupation, on receptor dimerization, or on G protein coupling is still unknown. Binding studies performed formerly with the same cell line [18] showed that hLH was significantly less potent than hCG in displacing [ I]hCG, suggesting different binding kinetics.

However, this is not sufficient to establish a difference in receptor affinity for the two hormones, since the same studies have not been performed in parallel using [ I]hLH. Future experiments should investigate which residues on the LHCGR, possibly in exon 10, are involved in distinguishing between the two hormones, whether both hLH and hCG induce receptor dimerization, and whether the same G proteins are activated by the two hormones.