APPLICATION OF A RADIOLIGAND RECEPTOR ASSAY FOR DETERMINATION OF LUTEINIZING HORMONE IN HUMAN SERUM

1976 ◽  
Vol 81 (1) ◽  
pp. 54-72 ◽  
Author(s):  
F. A. Leidenberger ◽  
R. Willaschek ◽  
V. G. Pahnke ◽  
L. E. Reichert
Keyword(s):  
Human Serum ◽  
Precipitation Method ◽  
Serum Samples ◽  
Serum Lh ◽  
Fractionation Procedure ◽  
Receptor Assay ◽  
Menopausal Women ◽  
Post Menopausal ◽  
Radioligand Receptor Assay ◽  
Lh Releasing Hormone

ABSTRACT A sensitive, specific and economic radioligand receptor assay is described for measurement of LH in human serum (RRA-LH). By means of ethanol fractionation or (NH4)2SO4-precipitation serum can be prepared for LH-quantitation and tested in the RRA-LH without interference of a nonspecific inhibiting substance present in untreated serum from various human sources. Treatment of serum with 8 % ethanol separates nonspecific inhibiting substances from LH, the latter remaining in the supernatant at this ethanol concentration. The criteria of specificity are examined. The results of experiments designed to produce evidence for or against specificity suggest specificity of the RRA-LH. Recoveries, as estimated by administration of [125I]hLH and unlabelled hLH to untreated serum samples are shown to be between 80 and 95 % for the ethanol fractionation procedure and between 65 and 75 % for the (NH4)2SO4-precipitation method. The ethanol fractionation procedure is preferred for routine serum-LH determination because of its simplicity, speed and higher recoveries. Ethanol-treated sera from post-menopausal women show, on average, higher RRA-LH concentrations than ethanol-treated sera from young women. RRA-LH values are consistently higher than LH-values found by radioimmunoassay (RIA-LH). The LH-concentrations in sera from two menstrual cycles and from two LH-releasing hormone tests are measured by RRA-LH and by RIA-LH. Similarities and discrepancies of the LH-profiles found by the two assay systems are described.

DETERMINATION OF LUTEINIZING HORMONE IN BOVINE BLOOD BY RADIOLIGAND RECEPTOR ASSAY AND COMPARISON WITH RADIOIMMUNOLOGICAL EVALUATION

1978 ◽  
Vol 87 (2) ◽  
pp. 268-278 ◽  
Author(s):  
D. Schams ◽  
C. Menzer
Keyword(s):  
Luteinizing Hormone ◽  
Close Correlation ◽  
Exchange Chromatography ◽  
Bovine Blood ◽  
Serum Samples ◽  
Bovine Plasma ◽  
Receptor Assay ◽  
C 50 ◽  
Radioligand Receptor Assay

ABSTRACT A sensitive and specific radioligand receptor assay (RRA) using rat testis homogenate as the receptor source is described for measurement of luteinizing hormone (LH) in bovine blood. Interfering and non-specific substances in blood were removed by means of ion-exchange chromatography on CM-Sephadex C-50. Criteria of validation such as recovery of added LH to plasma or serum, reproducibility, and specificity gave good results. Inhibition curves obtained with bovine plasma and serum were parallel to those obtained with the bovine standard preparation. The range of the dose-response curve was between 0.5–20 ng of bovine LH. The pattern of LH concentrations in purified serum samples under different physiological conditions such as during the oestrous cycle and after administration of GnRH showed a very close correlation whether measured by means of radioimmunoassay (RIA) or receptor assay. Values of RRA-LH were consistently higher than those of RIALH. Thus the lower the RIA-LH levels, the more pronounced were the discrepancies between results of both assay systems. The mean ratio of RRA-LH/RIA-LH for basal levels (less than 1 ng RIA-LH/ml plasma) was 17.8 as compared to a mean ratio for higher peak values (more than 20 ng RIA-LH/ml plasma) of only 1.2.

scholarly journals Association of c/t polymorphism in the lrp5 gene with circulating follicle stimulating hormone in Caucasian postmenopausal women

2007 ◽  
pp. 735-739
Author(s):  
I Žofková ◽  
M Hill ◽  
K Zajíčková
Keyword(s):  
Postmenopausal Women ◽  
Sex Hormones ◽  
Restriction Analysis ◽  
Follicle Stimulating Hormone ◽  
Serum Levels ◽  
Mediating Role ◽  
Serum Lh ◽  
Menopausal Women ◽  
Post Menopausal ◽  
Stimulating Hormone

The LRP5 gene is believed to be primarily associated with bone metabolism via Wnt signaling. The latter pathway, however, appears to control various other systems outside the skeleton. To find the relationships of the LRP5 gene to serum follicle stimulating hormone (FSH) and luteinizing hormone (LH) in the cohort of normal postmenopausal women, we identified the C/T (c.4037:A1330V) polymorphism in the LRP5 gene using a restriction analysis of the PCR product in a cohort of 165 untreated pre- and post-menopausal women. In a subset of 111 post-menopausal women we analyzed the association between the LRP5 genotype and serum levels of sex-hormones including FSH and LH. The distribution of CC, TC and TT genotypes of the C/T polymorphism in the whole group was 73.9 %, 23.6 % and 2.4 %, respectively, which is comparable with other Caucasian populations. As no TT homozygote was found in the group of post-menopausal women, serum sex-hormones were compared between CC and TC genotypes. Women with the CT allele combination had markedly higher serum FSH levels as compared to carriers of the CC genotype (p<0.004). No differences between these genotypes were found in serum LH levels as well as the circulating sex-steroids such as estradiol, testosterone, dehydroepiandrosterone and/or its sulphate, androstenedione and SHBG. To conclude, the LRP5 gene is associated with circulating FSH in normal post-menopausal women in the present study. The mediating role of subtle undetectable variations in estrogen levels is discussed. We did not find any relationship between the LRP-5 genotype and serum LH levels.

scholarly journals Effects of resistance exercise on lipolysis pathway in obese pre and postmenopausal women

2020 ◽  
Author(s):  
Kyu-Min Park ◽  
Seung-Taek Lim ◽  
Kun-Young Sung ◽  
Sunghwun Kang
Keyword(s):  
Resistance Exercise ◽  
Hormone Sensitive Lipase ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fatty Tissue ◽  
Serum Samples ◽  
Protein Levels ◽  
Menopausal Women ◽  
Subcutaneous Fatty Tissue ◽  
Hormone Sensitive ◽  
Post Menopausal

Abstract Background and objectives: The purpose of study was to examine the effects of regular resistance exercise for 12 weeks on lipolysis pathway in pre- and post- menopausal women with obesity. Methods: Twenty-three pre- and post- menopausal women with body fat percentages of 30% or more divided into pre- menopausal group (n=9) and post- menopausal group (n=14). All subjects participated in resistance exercise training for 12 weeks. Anthropometric and physical fitness tests were performed on all participants. Protein analyses were performed with subcutaneous fatty tissue extracted, and the samples were analyzed of relevant protein levels changes by using Western blotting. All serum samples were submitted for enzyme-linked immunosorbent assay measurements of adipocyte factors. Results: After 12 weeks between pre- menopausal and post- menopausal groups adipose triglyceride lipase (ATGL), monoacylglycerol lipase (MGL) and perilipin (PLIN) protein levels were significantly lower in the post- menopausal group than in the pre- menopausal group. Hormone-sensitive lipase (HSL) protein levels were significantly higher in the post- menopausal group than in the pre- menopausal group. In addition, leptin concentration was significantly decreased after resistance exercise in the post- menopausal group. Adiponectin concentration was significantly increased after resistance exercise in the both groups. Conclusions: This study indicates that regular resistance exercise to change of leptin and adiponectin might be release of reduction of % fat, and driving overall greater change ATGL, HSL, MGL and PLIN levels in subcutaneous fatty tissue in the obese post- menopausal group more than obese pre- menopausal group.

scholarly journals Effects of regulatory exercise on lipolysis pathway in obese pre and postmenopausal women

2020 ◽  
Author(s):  
Kyu-Min Park ◽  
Seung-Taek Lim ◽  
Kun-Young Sung ◽  
Sunghwun Kang
Keyword(s):  
Protein Expression ◽  
Resistance Exercise ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fatty Tissue ◽  
Serum Samples ◽  
Resistance Exercise Training ◽  
Menopausal Women ◽  
Fitness Tests ◽  
Subcutaneous Fatty Tissue ◽  
Post Menopausal

Abstract Background The purpose of study was to examine the effects of regulatory resistance exercise for 12 weeks on lipolysis pathway in pre- and post- menopausal women with obesity. Methods Twenty-three pre- and post- menopausal women with body fat percentages of 30% or more divided into pre- menopausal group (n = 9) and post- menopausal group (n = 14). All subjects participated in resistance exercise training for 12 weeks. All participant’s anthropometric measurements and physical fitness tests were performed. Protein analyses were performed with subcutaneous fatty tissue extracted, and the samples were analyzed of relevant protein expression changes by using Western blotting. All serum samples were submitted for enzyme-linked immunosorbent assay measurements of adipocyte factors. Results After 12 weeks between pre- menopausal and post- menopausal groups ATGL, MGL and PLIN protein expression were significantly lower in the post- menopausal group than in the pre- menopausal group. HSL protein expression were significantly higher in the post- menopausal group than in the pre- menopausal group. In addition, leptin concentration was significantly decreased, and adiponectin concentration was significantly increased after resistance exercise in the post- menopausal group more than pre- menopausal group. Conclusions In this study indicates that regular resistance exercise to change of leptin and adiponectin might be release of overall decreased ATGL, HSL, MGL and PLIN expression in subcutaneous fatty tissue, and driving reduction of % fat in the obese post- menopausal group more than obese pre- menopausal group.

scholarly journals Correlation between Reproductive Hormonal Level and Osteoporosis among Women in Mongolia

2016 ◽  
Vol 4 (2) ◽  
Author(s):  
Unentsatsral Lkhagvasuren ◽  
Sarantuya Jav ◽  
Battogtokh Zagdsuren
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Rank Order ◽  
Fragility Fractures ◽  
Serum Estradiol ◽  
Mineral Density ◽  
Serum Lh ◽  
Menopausal Women ◽  
The Mean ◽  
Post Menopausal

Background: Postmenopausal osteoporosis is the most common bone metabolic disease associated with low bone mineral density (BMD) and osteopathic fragility fractures, which can lead to significant morbidity. The objective of this study was to investigate the relationship between serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), and estradiol (E2) levels and bone mineral density (BMD) across the stages of menopause in Mongolian women.Methods: Two hundred sixty participants aged 50.1±4.4 years were enrolled in the study. Blood samples were obtained from each participant and analyzed using ELISA. Data were first stratified and analyzed by bone mineral density status (osteoporotic, osteopenic, and normal) and then by menopause status. Between group differences were analyzed using t-tests, and correlations were assessed using the Spearman rank order test, with Bonferonni correction. The data were analyzed using Statistical Package Statistical Software version 20.0 (SPSS Inc., Chicago, IL). Significance was set at p<0.05.Results: The mean menopausal age was 48.4±3.4, which is comparable to the Mongolian population mean menopausal age. The mean serum estradiol level in the normal BMD group was 18.3±13.1 pg/ml and  15.8±10.7 pg/ml in the osteoporotic group. The mean serum FSH in the normal BMD group was 54.5±44.1 pg/ml and 81.3±34.2 pg/ml in the osteoporotic group. The mean serum LH level in the normal BMD group was 53.1±41.2 and 75.1±26.1 pg/ml in the osteoporotic group. The mean T and Z score were lower in the osteoporotic group. FSH and LH levels significantly differed across menopause stages in that those who were post-menopausal had higher levels compared to those who were pre- or peri-menopausal. Both hormones, FSH and LH, showed weak negative correlations with BMD level, but not E2. There were significant negative correlations between FSH and Speed of Sound (SOS) (r=-0.16; p<0.01), and  between osteoporosis with age (r=-0.30, p<0.05) and number of childbirths (r=-0.14 p<0.05). Discussion: Osteoporosis is a significant problem with associations to hormone levels in post-menopausal women. In our study, mean serum estradiol levels decreased with age, and the mean FSH and LH levels were higher in women of later menopausal stage. Further study is warranted to investigate the bone related studies to establish better statistical references among Mongolian women. 

Development of a radioligand receptor assay for measuring follitropin in serum: application to premature ovarian failure

1991 ◽  
Vol 37 (4) ◽  
pp. 508-514 ◽  
Author(s):  
Alan L Schneyer ◽  
Patrick M Sluss ◽  
Randall W Whitcomb ◽  
Janet E Hall ◽  
William F Crowley ◽  
...  
Keyword(s):  
Receptor Binding ◽  
Premature Ovarian Failure ◽  
Ovarian Failure ◽  
Fsh Receptor ◽  
Serum Samples ◽  
Receptor Assay ◽  
Radioligand Receptor Assay ◽  
Fsh Bioactivity ◽  
Free Serum

Abstract We have developed a radioligand receptor assay (RRA) with sufficient sensitivity and specificity for quantifying follitropin (FSH) in unextracted serum samples. Standard curves prepared by adding pituitary FSH to either buffer or gonadotropin-free serum were parallel and statistically indistinguishable in this assay, whereas gonadotropin-free serum alone had no activity. Cross-reactivity with related pituitary hormones was negligible. Pituitary FSH was calibrated with commonly used reference preparations so that RRA results could be compared with RIA results for identical standards. The patterns in daily blood samples in six normal menstrual cycles were similar by both methods. The mean RIA:RIA ratio in both the follicular and luteal phases was between 0.6 and 0.7, and at mid-cycle decreased to 0.48, suggesting an alteration of isohormone composition at mid-cycle. In 27 women with premature ovarian failure, RRA:RIA ratios ranged from below the RRA minimum detectable dose to 4.6, suggesting that immunoreactive FSH might not be capable of binding to the FSH receptor in some patients, whereas in patients with high RRA:RIA ratios, circulating inhibitors of FSH receptor binding might be present and perhaps contributing to the observed ovarian failure. Use of this RRA in conjunction with RIA and in vitro bioassays may better define the relative contribution of FSH isohormones, autocrine or paracrine modulators of FSH bioactivity, and FSH-receptor binding competitors to the "total FSH biological signal" as detected by the gonadal FSH receptor.

scholarly journals Effects of regulatory exercise on lipolysis pathway in obese pre and postmenopausal women

2020 ◽  
Author(s):  
Kyu-Min Park ◽  
Seung-Taek Lim ◽  
Kun-Young Sung ◽  
Sunghwun Kang
Keyword(s):  
Protein Expression ◽  
Resistance Exercise ◽  
Enzyme Linked Immunosorbent Assay ◽  
Fatty Tissue ◽  
Serum Samples ◽  
Resistance Exercise Training ◽  
Menopausal Women ◽  
Fitness Tests ◽  
Subcutaneous Fatty Tissue ◽  
Post Menopausal

Abstract Background and objectives: The purpose of study was to examine the effects of regulatory resistance exercise for 12 weeks on lipolysis pathway in pre- and post- menopausal women with obesity. Methods: Twenty-three pre- and post- menopausal women with body fat percentages of 30% or more divided into pre- menopausal group (n=9) and post- menopausal group (n=14). All subjects participated in resistance exercise training for 12 weeks. All participant’s anthropometric measurements and physical fitness tests were performed. Protein analyses were performed with subcutaneous fatty tissue extracted, and the samples were analyzed of relevant protein expression changes by using Western blotting. All serum samples were submitted for enzyme-linked immunosorbent assay measurements of adipocyte factors. Results: After 12 weeks between pre- menopausal and post- menopausal groups ATGL, MGL and PLIN protein expression were significantly lower in the post- menopausal group than in the pre- menopausal group. HSL protein expression were significantly higher in the post- menopausal group than in the pre- menopausal group. In addition, leptin concentration was significantly decreased, and adiponectin concentration was significantly increased after resistance exercise in the post- menopausal group more than pre- menopausal group. Conclusions: In this study indicates that regular resistance exercise to change of leptin and adiponectin might be release of overall decreased ATGL, HSL, MGL and PLIN expression in subcutaneous fatty tissue, and driving reduction of % fat in the obese post- menopausal group more than obese pre- menopausal group.

scholarly journals Validation and Optimization of a Simple RP-HPLC Method for Determination of Trimetazidine in Human Serum and its Application in a Pharmacokinetic Study with Healthy Bangladeshi Male Volunteers

2012 ◽  
Vol 10 (2) ◽  
pp. 71-78 ◽  
Author(s):  
Md Mazharul Islam Chowdhury ◽  
Md Ashik Ullah ◽  
Abdullah Al Maruf ◽  
Mohammad Safiqul Islam ◽  
Maizbha Uddin Ahmed ◽  
...  
Keyword(s):  
Human Serum ◽  
Pharmacokinetic Study ◽  
Potassium Dihydrogen Phosphate ◽  
Internal Standard ◽  
Hplc Method ◽  
Precipitation Method ◽  
Dihydrogen Phosphate ◽  
Serum Samples ◽  
Limit Of Quantification ◽  
Relative Standard

Trimetazidine is an effective and well-tolerated antianginal drug. In the present study, a simple, sensitive  and specific liquid chromatography (HPLC) method with UV detection was developed and validated for the  quantification of trimetazidine in human serum samples using caffeine as internal standard. Protein precipitation  method with methanol was employed in the extraction of trimetazidine and caffeine from biological matrix. The  chromatographic separation was accomplished on Xterra C18 Column with a mobile phase consisting 0.01 M  potassium dihydrogen phosphate buffer (pH 4.16 ± 0.01 adjusted with orthophosphoric acid, with a solvent system of  triethanolamine and acetonitrile (90:10) at a flow rate of 1.0 ml/min. The chromatogram was monitored at a  wavelength of 207 nm. The method was validated over a linear concentration range of 5-200 ng/ml and limit of  quantification (LOQ) was 5.0 ng/ml with a coefficient of correlation (r2) ? 0.996. The intra-day and inter-day  precision expressed as relative standard deviation was 3.40%-11.63% and 1.30%-10.21%, respectively. The average  recovery of trimetazidine from serum was 97.44%. The method was successfully applied to a pharmacokinetic study  after oral administration of modified release trimetazidine hydrochloride tablet (35 mg) in healthy Bangladeshi  volunteers. DOI: http://dx.doi.org/10.3329/dujps.v10i2.11783 Dhaka Univ. J. Pharm. Sci. 10(2): 71-78, 2011 (December)  

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