Bioactive Luteinizing Hormone Levels Research Articles

Changes of urinary steroid conjugates and gonadotropin excretion in the menstrual cycle and pregnancy in the Yunnan snub‐nosed monkey (Rhinopithecus bieti)

The Yunnan snub-nosed monkey (Rhinopithecus bieti) is one of the most endangered species in the world, and it is endemic to China. According to our knowledge, there was no information on reproduction for this species. The present study was designed to understand the characteristics of reproductive hormone secretion during the menstrual cycle and pregnancy of this species by monitoring urinary estrone conjugate (E1C), pregnanediol-3-glucuronide (PdG), bioactive follicle-stimulating hormone (FSH), and luteinizing hormone (LH). The urine samples were collected each day from four adult females for eight menstrual cycles, and once in 3 days during pregnancy (three full-term pregnancies, one mid-term abortion). The steroid conjugate was tested by radioimmunoassays (RIAs), and bioactive FSH and LH levels were measured in vitro by the sensitive bioassays granulosa cell aromatize bioassay (GAB) and rat interstitial cell testosterone (RICT), respectively. The results showed that: 1) E1C presented a preovulatory peak (183.9 +/- 8.6 ng/mgCr) followed by a definite elevation of PdG; 2) PdG in the luteal phase (754.4 +/- 30.6 ng/mgCr) was three- to fivefold higher than during the corresponding follicular phase (198.3 +/- 11.4 ng/mgCr); 3) the peaks of bio-LH and bio-FSH were on the same day, while the E1C peak was 1 or 2 days before the peaks for these two hormones; 4) bio-FSH levels were higher in the follicular phase than in the luteal phase, and bio-LH levels elevated slightly in the luteal phase; 5) the mean cycle length was 23.6 +/- 3.5 days (n = 3) based upon successive urinary LH peaks; 6) based on the interval from the day of E1C peak to the day of parturition, the gestation was 203.7 +/- 2.5 days (n = 3); and 7) both E1C and PdG increased and remained high after pregnancy, with a sharp decrease in basal levels following parturition or mid-term abortion. The results suggested that the pattern of reproductive hormones for R. bieti is similar to that of other Old World monkeys, but the concentration of the hormones is different from that of other species. This species has a longer progestation period, which may be related to its classification status.

Increased bioactive luteinizing hormone levels in postmenopausal women with endometrial cancer

International Journal of Gynecology & ObstetricsVolume 42, Issue 2 p. 224-224 Citations from the literature gynecological endocrinology Increased bioactive luteinizing hormone levels in postmenopausal women with endometrial cancer M. Nagamani, M. NagamaniSearch for more papers by this authorM.G. Doherty, M.G. DohertySearch for more papers by this authorE.R. Smith, E.R. SmithSearch for more papers by this authorY. Chandrasekhar, Y. ChandrasekharSearch for more papers by this author M. Nagamani, M. NagamaniSearch for more papers by this authorM.G. Doherty, M.G. DohertySearch for more papers by this authorE.R. Smith, E.R. SmithSearch for more papers by this authorY. Chandrasekhar, Y. ChandrasekharSearch for more papers by this author First published: August 1993 https://doi.org/10.1016/0020-7292(93)90675-MAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume42, Issue2August 1993Pages 224-224 RelatedInformation

Validation of an improved in vitro bioassay to measure LH in diverse species.

Cultured Leydig tumor cells (MA-10) respond to luteinizing hormone (LH) by synthesizing and secreting progesterone (P). The specificity of the response to LH prompted us to develop this system for use as a simple and rapid in vitro bioassay for LH. The aims of this study were to (1) improve sensitivity and reproducibility, and (2) optimize the assay for use in diverse animal species. A minimum sensitivity was observed at 0.05 mlU/well of LH with 0.5 x 10(4) cells/well for 1.5 hours. At higher concentrations of LH, shorter incubation periods also significantly stimulated P production. Addition of human LH standard or serum samples resulted in a dose-dependent increase in P production. Parallel dose-dependent curves were observed with LH preparations from mammalian, avian, and amphibian species. In conclusion, these findings demonstrate that (1) the assay is rapid, sensitive, and reproducible; (2) serum LH levels analyzed using this assay and the mouse Leydig cell bioassay are comparable; (3) shorter incubation times suggest the implementation of this assay for rapid qualitative determination of LH surges; and (4) the assay can be used for the analysis of samples from diverse species, especially those lacking radioimmunoassays. Therefore, this assay system allows for the simple and rapid measurement of circulating bioactive LH levels in humans and diverse animal species, and should provide insight regarding the role of bioactive LH in physiological and pathological conditions.

Increased bioactive luteinizing hormone levels in postmenopausal women with endometrial cancer

OBJECTIVE: The purpose of our study was to investigate the secretion of immunoactive and bioactive luteinizing hormone in postmenopausal women with endometrial cancer.STUDY DESIGN: Seventeen postmenopausal women with endometrial cancer and nine without cancer were studied. Blood samples were collected at 15-minute intervals for 360 minutes. All samples were assayed for bioactive luteinizing hormone by rat interstitial cell testosterone assay and for immunoactive luteinizing hormone by radioimmunoassay. Serum pooled from 6-hour sampling was assayed for follicle-stimulating hormone, total estradiol, unbound estradiol, and estrone.RESULTS: Patients with endometrial cancer had significantly (p \\lt 0.01) higher bioactive luteinizing hormone levels (mean ± SE 276 ± 26 IU/L) as compared with those of control women (144 ± 18 IU/L). Bioactive/immunoactive ratios of luteinizing hormone were significantly higher (p \\lt 0.01) in women with cancer {5.8 ± 0.7) than in those without cancer (2.5 ± 0.5). There was a significant (p \\lt 0.001) positive correlation (r = 0.582) between unbound estradiol levels and bioactive luteinizing hormone concentrations.CONCLUSIONS: There is an increase in bioactive luteinizing hormone secretion in postmenopausal women with endometrial cancer. This could lead to an increase in ovarian androgen production resulting in increased prehormone availability for estrogen formation from peripheral conversion. (AM J OBSTET GYNECOL 1992;167:1825-30.)

Clinical Features and Circulating Gonadotropin, Insulin, and Androgen Interactions in Women with Polycystic Ovarian Disease

Objective To investigate the interactions of hyperinsulinemia and inappropriate gonadotropin secretion in women with polycystic ovarian disease (PCOD). Design Comparative study of endocrinologic parameters in subjects with PCOD. Setting Open patient clinic of reproductive endocrinology at University Central Hospital of Turku, Finland. Patients Fourteen nonobese and 10 obese patients with PCOD. Seven healthy women for reference data collection. Normal thyroid function, serum prolactin concentration, normal diurnal cortisol variation, euglycemia in all subjects. Main Outcome Measures Serum concentrations of insulin, testosterone, androstenedione, dehydroepiandrosterone sulfate, sex hormone-binding globulin, immunoreactive luteinizing hormone (LH), bioactive LH, and follicle-stimulating hormone (FSH). Results The concentration of insulin was higher and that of bioactive LH was lower in obese than in nonobese PCOD women in whom the levels were also above the upper reference value. There was a negative correlation between insulin and bioactive LH levels (r = —0.57). Bioactive LH correlated inversely with the body mass index (BMI) (r = —0.50). After eliminating the effect of the BMI, the correlation between bioactive LH and insulin was no longer significant (r = —0.37). The bioactive LH and immunoreactive LH/FSH ratio correlated significantly (r = 0.68). Conclusions These data demonstrate that hyperandrogenic women can be divided into two subgroups: those with insulin resistance, normal or minimally elevated LH, and markedly elevated insulin levels; and those with elevated LH levels, no insulin resistance, and normal insulin concentrations. Obesity is associated with the former, and high bioactive LH levels with the latter subgroup.

Pattern of secretion of bioactive and immunoreactive gonadotrophins in normal pubertal children

The aim was to investigate the relationship between the nocturnal pulsatile secretory patterns of immunoreactive and bioactive luteinizing hormone in normal children at various stages of puberty. Blood samples were taken at 15-minute intervals from 2000 hours to 0800 hours. Pubertal stage was assessed by the method of Tanner (1962). Thirty-four healthy siblings (17 males, 17 females) of diabetic children were recruited (median age 13.1, range 9.1-20.9 years). They were of normal height, non-obese, and covered the range of puberty. Follicle stimulating and luteinizing hormone levels were measured by radioimmunoassay in all 34 subjects; bioactive LH (B-LH) was assayed in a subgroup of 13 subjects selected to encompass the range of normal puberty. Oestradiol (girls) and testosterone (boys) were also measured at hourly intervals. Immunoreactive luteinizing and follicle stimulating hormone concentrations showed a progressive rise during puberty in both sexes. FSH concentrations were significantly higher in females than in males at all stages of puberty. Overnight mean bioactive luteinizing hormone concentrations were higher than immunoreactive luteinizing hormone levels in all the girls studied (n = 7). Although the number of bioactive luteinizing hormone pulses (31) was greater than immunoreactive pulses (27), the profiles were generally very similar. In the early pubertal girls an increase in the bioactive: immunoreactive ratio was observed during the middle of the night with the onset of pulsatility. Oestrogen was detected in the girls in breast stage 4-5 but not in two of the early pubertal girls, despite pulses of immunoreactive and bioactive luteinizing hormone. The boys had higher mean bioactive than immunoreactive luteinizing hormone levels and overall bioactive and immunoreactive luteinizing hormone and testosterone concentrations increased with puberty stage. Concordance between bioactive and immunoreactive hormone pulses was good although more immunoreactive pulses (16) were seen than bioactive pulses (14). As in the girls, an increase in the bioactive: immunoreactive ratio was observed in the middle of the night with the onset of pulsatility at genital stage 2 but, in contrast to the oestrogen data in the girls, testosterone secretion always followed luteinizing hormone pulsatility overnight. We conclude that mean overnight immunoreactive luteinizing and follicle stimulating hormone concentrations increase during puberty in both sexes. Bioactive luteinizing hormone levels are two to three times higher than immunoreactive luteinizing hormone in both sexes, but there is very little discordance between immunoreactive and bioactive luteinizing hormone pulsatility. The bioactive: immunoreactive ratio increases with the occurrence of pulsatility overnight in early pubertal children. The relationship between these changes in bioactive and immunoreactive luteinizing hormone and sex steroids is clearest in boys where the nocturnal testosterone rise always follows pulsatile LH secretion.

Clinical features and circulating gonadotropin, insulin, and androgen interactions in women with polycystic ovarian disease

To investigate the interactions of hyperinsulinemia and inappropriate gonadotropin secretion in women with polycystic ovarian disease (PCOD). Comparative study of endocrinologic parameters in subjects with PCOD. Open patient clinic of reproductive endocrinology at University Central Hospital of Turku, Finland. Fourteen nonobese and 10 obese patients with PCOD. Seven healthy women for reference data collection. Normal thyroid function, serum prolactin concentration, normal diurnal cortisol variation, euglycemia in all subjects. Serum concentrations of insulin, testosterone, androstenedione, dehydroepiandrosterone sulfate, sex hormone-binding globulin, immunoreactive luteinizing hormone (LH), bioactive LH, and follicle-stimulating hormone (FSH). The concentration of insulin was higher and that of bioactive LH was lower in obese than in nonobese PCOD women in whom the levels were also above the upper reference value. There was a negative correlation between insulin and bioactive LH levels (r = -0.57). Bioactive LH correlated inversely with the body mass index (BMI) (r = -0.50). After eliminating the effect of the BMI, the correlation between bioactive LH and insulin was no longer significant (r = -0.37). The bioactive LH and immunoreactive LH/FSH ratio correlated significantly (r = 0.68). These data demonstrate that hyperandrogenic women can be divided into two subgroups: those with insulin resistance, normal or minimally elevated LH, and markedly elevated insulin levels; and those with elevated LH levels, no insulin resistance, and normal insulin concentrations. Obesity is associated with the former, and high bioactive LH levels with the latter subgroup.

Testicular steroidogenesis in X/X sex‐reversed mice

The sex-reversed X/X Sxr mouse is phenotypically male but lacks germ cells. This provides the opportunity to examine Leydig cell function in the absence of a normal germinal epithelium and without experimental manipulation of the testis. Serum testosterone was lower in Sxr males compared to normal (X/Y) males but there was no significant difference in intratesticular testosterone levels. Serum immunoactive and bioactive luteinizing hormone levels were not significantly different between the two groups. Injection of human chorionic gonadotrophin (hCG) increased intratesticular testosterone in Sxr males more than in normal males although there was no difference in serum testosterone levels. These differences in circulating and intratesticular testosterone levels may be related to reduced blood flow through the Sxr testis. Both basal and hCG-stimulated androgen production by whole testes in vitro were not significantly different between normal and Sxr males. Androgen production per Leydig cell, however, was significantly reduced in cells from Sxr males; this difference was apparent under basal conditions and following stimulation with hCG, dibutyryl cyclic AMP, 22R-hydroxycholesterol or pregnenolone. Results show that in the absence of a normal germinal epithelium there is a decrease in the steroidogenic capacity of the Leydig cells although steroidogenesis by the whole testis is not impaired significantly.

Marked suppression of gonadotropins and testosterone by an antagonist analog of gonadotropin-releasing hormone in men

To study the dose response characteristics of a gonadotropin-releasing hormone (GnRH) antagonist ([Ac-D2-Nal1,D4-Cl-Phe2,D3-Pal3,Arg5,dGlu6 (AA), d-Ala10] GnRH; Nal-Glu), 1.5 or 5.0 mg of Nal-Glu were administered to two groups of five normal men by daily subcutaneous injection for 21 days. Serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone (T) were determined on multiple occasions before, during, and after the antagonist treatment. Five milligrams Nal-Glu markedly suppressed mean serum immunoreactive LH to a mean of 1.5 +/- 0.4 IU/L (+/- SEM), immunoreactive FSH to the limit of assay detection (1 IU/L), and lowered basal mean serum T to castrate range (less than 2 nmol/L). Serum bioactive LH levels also showed a marked decrease in the 5.0-mg group similar to that seen in immunoreactive LH levels. Amplitude of immunoreactive LH pulses was markedly reduced in the 5.0-mg group on day 21. A 1.5-mg dose of Nal-Glu transiently suppressed serum immunoreactive LH levels on day 1. There was a subsequent escape on the rest of the days sampled. Serum immunoreactive FSH levels were not significantly changed over the 21-day treatment period. Serum T levels were transiently suppressed only on day 1 paralleling immunoreactive LH suppression. No adverse systemic side effects occurred. Thus, the 5.0-mg dose of this GnRH antagonist provides a pharmacological means of markedly suppressing the hypothalamic-pituitary-gonadal axis and, therefore, has potential as a male contraceptive.

Suppression of Bioactive Luteinizing Hormone and Testosterone by a Progesterone Antagonist ZK 98.734 in Adult Male Common Marmosets, Callithrix Jacchus

The effects of a progesterone antagonist ZK 98.734 on release of bioactive luteinizing hormone (LH) and testosterone were studied in adult male common marmosets by using the following experimental protocols: (1) the blocking of the nocturnal rise in testosterone levels by ZK 98.734, (2) the pharmacodynamic effects of ZK 98.734 on testosterone and LH levels, (3) the reversal of ZK 98.734-induced decrease in testosterone by treatment with human chorionic gonadotropin (hCG), and (4) the blocking of estradiol-induced positive feedback release of LH by ZK 98.734. Sixteen adult male common marmosets were used for different experiments after resting them for at least 4 wk between experiments. Testosterone and bioactive LH levels were measured by specific radioimmunoassay and in vitro bioassay methods, respectively. Treatment (i.m.) of male common marmosets (n = 6/group) with ZK 98.734 (1 mg or 5 mg/day) at 1700 h for 3 consecutive days significantly (p less than 0.05) suppressed the nocturnal (2200 h) rise in testosterone levels. The effects of the two doses were not dose-related; however, the decrease on the first day of treatment was more pronounced with the 5-mg dose than with the 1-mg dose. Diurnal rhythms were restored during the post-treatment period. Similarly, treatment with ZK 98.734 (5 mg, n = 8/group) at 1000 h caused a decrease in testosterone and LH levels. The levels were significantly (p less than 0.05) lower at 3 and 6 h after treatment compared to pretreatment levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of orally administered oestrogens on gonadotrophin levels in post-menopausal women

The gonadotrophin-suppressing effect of 4 peroral oestrogen regimens (A: 2.5 mg piperazine oestrone sulphate; B: 1.25 mg piperazine oestrone sulphate + 5.0 mg oestriol; C: 2.0 mg oestradiol valerate; D: 10.0 mg oestriol; all administered daily) was studied in 7 post-menopausal women, in the absence, and then in the presence of daily oral doses of 250 μg of levonorgestrel. A randomized, complete cross-over design was used, and from each volunteer 80 blood samples were drawn during a period of 252 days for the assay of immunoreactive follicle stimulating hormone (FSH), luteinizing hormone (LH) and bioactive LH levels. All 4 formulations significantly diminished pretreatment gonadotrophin levels. Combination with levonorgestrel enhanced the suppressive effects. Subsequent placebo administration for a week restored gonadotrophin levels to those found previously during oestrogen administration, but not to pretreatment levels. Regimen D exhibited the relatively weakest and regimens A and B the strongest suppression, both in the absence and in the presence of levonorgestrel. Treatment with all oestrogen formulations decreased, and the addition of levonorgestrel increased the ratio of bioactive (B) to immunoreactive (I) LH. Seven days of placebo administration abolished the effect of levonorgestrel, but not that of the various oestrogens on the B I ratios.

Pulsatile secretion of bioactive luteinizing hormone in adult male rhesus macaques: acute and chronic effects of orchidectomy.

Serum concentrations of bioactive luteinizing hormone (LH) and of testosterone were measured in adult male rhesus macaques at the time of, and at least 6 wk after orchidectomy. The effects of anesthesia alone and of sham surgery on the secretion of these hormones were also studied. Contrary to expectations based on current notions of the negative feedback actions of testosterone on gonadotropin secretion, pulsatile LH release was absent for an average of 9.3 h immediately after removal of the testes. Animals that were subjected to sham surgery or anesthesia alone showed a delay of 4.4 h in the reappearance of LH secretion, similar to the lull in LH pulsations normally observed at the time of day. When LH secretion resumed in the acutely castrated animals, the pulses continued for the remainder of the sampling period and did not show the midmorning decrease in activity characteristic of intact or sham-operated animals. In the animals that were castrated, circulating cortisol was elevated approximately twofold above levels observed in sham-operated animals for a period of 8 h, beginning immediately after castration. In the long-term (greater than 6 wk) castrated male macaques, circulating bioactive LH levels were eightfold greater (24 micrograms/ml) than levels observed in intact animals (3 micrograms/ml). The frequency of LH pulses in the castrated animals, as determined by PULSAR analysis, was significantly influenced by sampling frequency. When blood samples were taken at 15-min intervals for 24 h, LH pulse frequency averaged 7 pulses/12 h. If samples were collected every 7 min for 12 h, the frequency increased to 13 pulses/12 h.(ABSTRACT TRUNCATED AT 250 WORDS)

Modulation of luteinizing hormone immunoreactivity and bioactivity by dopamine but not norepinephrine in women

It has been suggested that changes in bioactive luteinizing hormone in women occur toward midcycle and may result in increased bioactive/immunoreactive luteinizing hormone ratios. To determine whether dopamine or norepinephrine modulate immunoreactive and bioactive luteinizing hormone secretion, 15 ovulatory women were studied in the mid to late follicular phase. Dopamine in two doses (0.5 μg/kg/min and 4 μg/kg/min) and norepinephrine, 0.1 μg/kg/min, were infused for 4 hours, and metoclopramide, 10 mg intravenously, was also given to determine whether dopamine receptor antagonism results in changes. Bioactive luteinizing hormone and the bioactive/immunoreactive luteinizing hormone ratio increased in women from the early to late follicular phase (p < 0.05). Both intravenous doses of dopamine resulted in significant decrements in immunoreactive luteinizing hormone (20 ± 2 and 20 ± 3%, p < 0.02) and bioactive luteinizing hormone (36.7% and 43.2%, p < 0.05). With dopamine there was also a significant decrease in the bioactive/immunoreactive luteinizing hormone ratio (p < 0.02). Intravenous norepinephrine, however, resulted in no changes in either immunoreactive or bioactive luteinizing hormone levels. Metoclopramide also did not change immunoreactive or bioactive luteinizing hormone levels. These data suggest that although endogenous dopaminergic blockade may not play a significant role in determining basal levels of luteinizing hormone, decreases in dopamine at the pituitary level may increase the bioactive/immunoreactive luteinizing hormone ratio. Norepinephrine does not appear to exert major changes in immunoreactive or bioactive luteinizing hormone.