Mean Luteinizing Hormone Levels Research Articles

616 INFLUENCE OF RADICAL PROSTATECTOMY ON THE HYPOTHALAMIC-PITUITARY-GONADAL AXIS AND SPECIFICALLY IN SERUM FREE AND BIOAVAILABLE TESTOSTERONE

You have accessJournal of UrologyProstate Cancer: Basic Research1 Apr 2011616 INFLUENCE OF RADICAL PROSTATECTOMY ON THE HYPOTHALAMIC-PITUITARY-GONADAL AXIS AND SPECIFICALLY IN SERUM FREE AND BIOAVAILABLE TESTOSTERONE Juanma Bastarós Hernández, Fernando Agreda, Placer Jose, Planas Jacques, Carles Xavier Raventós, Luis Castro, Gueisy Delgado, and Juan Morote Juanma Bastarós HernándezJuanma Bastarós Hernández Barcelona, Spain More articles by this author , Fernando AgredaFernando Agreda Barcelona, Spain More articles by this author , Placer JosePlacer Jose Barcelona, Spain More articles by this author , Planas JacquesPlanas Jacques Barcelona, Spain More articles by this author , Carles Xavier RaventósCarles Xavier Raventós Barcelona, Spain More articles by this author , Luis CastroLuis Castro Barcelona, Spain More articles by this author , Gueisy DelgadoGueisy Delgado Barcelona, Spain More articles by this author , and Juan MoroteJuan Morote Barcelona, Spain More articles by this author View All Author Informationhttps://doi.org/10.1016/j.juro.2011.02.1469AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookTwitterLinked InEmail INTRODUCTION AND OBJECTIVES The role played by the prostate gland on the hypothalamic-pituitary-gonadal axis is not well documented and there are conflicting data regarding the behavior of serum testosterone after radical prostatectomy (RP) and its possible influence on libido and erectile dysfunction postoperatively. The aim of this study was to evaluate the influence of PR on the hypothalamic-pituitary-gonadal axis and specifically in serum free and bioavailable testosterone. METHODS We determined the serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin (PRL), total testosterone (TST), free testosterone (TSTl) before and three months after the PR and 60 patients with prostate cancer located (CAP) whose age ranged between 52 and 68 years. TSTbd was also calculated using the formula of Vermeulen from TST concentrations, albumin and SHBG. No patient included in the study had previously undergone pelvic radiation, or androgen suppression or 5ARIs therapy. All measurements were performed in central laboratory automated methods, in fasting and between 8:00 and 10:00 am. Statistical comparisons of means were performed using the Wilcoxon test. RESULTS Mean levels of LH were 3.48 U/l (2.85 to 4.11) before and 4.35 U/l (3.61 to 5.09) after PR (p = 0,001). Mean levels of FSH were 6.92 U/l (5.47 to 8.37) before and 8.32 U/l (6.51 to 10.14) after PR (p = 0.002). The average levels of PRL were 6.22 ng/mL (4.97 to 7.46) before and 7.32 ng/mL (5.81 to 8.84) after PR (0039). TST average levels were 496.75 ng/mL (456.47 to 537.36) before and 447.50 ng/mL (410.97 to 484.03) after PR (p = 0.009). TSTl average levels were 7.78 pg/mL (6.99 to 8.58) before and 7.60 pg/mL (6.69 to 8.50) after PR (p = 0.41). TSTbd average levels were 220.23 U/l (200.86 to 239.59) before and 212.86 U/l (196.32 to 229.4) after PR (p = 0.35). We did not detect an influence of Gleason grade of the tumor in the observed changes. CONCLUSIONS The prostate gland seems to have a feed back effect on the hypothalamic-pituitary-gonadal axis. Serum total testosterone were significantly reduced after the PR. However, the levels of free testosterone and bioavailable testosterone are not affected by the PR. © 2011 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 185Issue 4SApril 2011Page: e248 Advertisement Copyright & Permissions© 2011 by American Urological Association Education and Research, Inc.MetricsAuthor Information Juanma Bastarós Hernández Barcelona, Spain More articles by this author Fernando Agreda Barcelona, Spain More articles by this author Placer Jose Barcelona, Spain More articles by this author Planas Jacques Barcelona, Spain More articles by this author Carles Xavier Raventós Barcelona, Spain More articles by this author Luis Castro Barcelona, Spain More articles by this author Gueisy Delgado Barcelona, Spain More articles by this author Juan Morote Barcelona, Spain More articles by this author Expand All Advertisement Advertisement Loading ...

Ovarian reserve in young women with low birth weight and normal puberty: a pilot case–control study

Aim. Studies indicate that women born small for gestational age (SGA) have impaired ovarian function. The origin of this ovarian dysfunction is still debatable. The aim of this study was to compare ovarian ageing between girls born appropriate for gestational age (AGA) and SGA. Therefore, we measured Luteinizing hormone (LH), Follicle-stimulating hormone (FSH), E2, Anti-Müllerian hormone (AMH) levels and the pituitary response to endogenous Gonadotropin-releasing hormone (GnRH) in adolescent girls born SGA and AGA.Methods. A case–controlled pilot study consisting of seven SGA women (birth weight <10th percentile AGA) and 13 AGA women with regular menstrual cycles, age 19.9 (±0.42). Early follicular FSH, LH, Oestradiol (E2) and AMH levels were measured. After baseline samples, 100 μg GnRH was administered intravenously and at 30, 60 and 90 min blood samples were taken to measure gonadotropin levels and to compute the response to endogenous GnRH.Results. Mean follicular phase LH, FSH, E2 and AMH levels did not significantly differ between young women born SGA and AGA. Furthermore, the response to endogenous GnRH showed no significant differences either.Conclusions. We concluded against extension of this pilot study. Based on our observations it seems unlikely that limited ovarian reserve is a predominated problem in adolescent SGA.

Hyperprolactinemia And Hypergonadotropins In Infertile Males With Sever Oligospermia And Azoospermia

Serum prolactin (PRL), luteinizing hormone (LH), and follicle stimulating hormone (FSH) were analyzed in 120 infertile male including: 78(65%) asthenozoospermic, 24(20%) sever oligospermic, 10(8.3%), oligospermic, and 8(6.7%) azoospermic using immunometric assay. Hormonal seric values were correlated with sperm count, motility, and antisperm antibody as detected by Latex Agglutination Test . No clinical importance of autoantibody was appeared in all groups of subjects investigated. A significant week correlation was found between serum LH and sperm count in all infertile males (p=0.002) but not motility, whereas PRL and FSH showed an inverse relationship with motility (r = -0.469 p<0.005, r = -0.316 p< 0.005) respectively. The mean PRL level (reference range 2.5-17 ng/ml) was found to be higher in sever oligospermia and azoospermia (mean 17.9 ±12.7 and 18.6 ±11.7 respectively). On the other hand, the mean LH levels (reference range 0.8-7.6 mIU/ml) and FSH (reference range 0.7-11.1 mIU/ml) was found to be higher in azoospermia (19.9±14.9 and 24.8±32.4 respectively). Increasing profile of FSH and PRL is useful in routine investigation of azoospermic male (p=0.001). These data demonstrate that when using lower semen parameters, the most common serum hormone abnormality is increased in PRL and gonadotrophins. The study gives an impression concerning serum PRL, FSH, and LH in infertile males in Jordan.

Photoperiod and luteinizing hormone secretion in domestic and wild pigs

During seasonal anoestrus (long-days), oestradiol can effectively inhibit the pulsatile secretion of luteinizing hormone (LH) in sheep. The aim of our trial was to determine whether the same regulatory mechanism exists in the pig. Altogether, 20 ovariectomized and oestradiol-implanted gilts (16 domestic pigs, 4 European wild boars) were randomly allocated to two treatment groups. The first group was kept under a short-day light–dark cycle of 8L:16D, and the second group under a long-day light regime of 16L:8D. After a 6-week treatment period, blood samples were taken at 20-min intervals for 12 h. After sampling, the light regimens were switched. Sampling was then repeated following another 6 weeks of treatment. In both treatment groups, 2.3 LH pulses occurred every 12 h. The basal LH level was 0.7 ± 0.4 ng/ml for the short-day group and 1.0 ± 0.5 ng/ml for the long-day group. The mean LH level was 0.9 ± 0.4 and 1.3 ± 0.6 ng/ml and the LH pulse amplitude 0.5 ± 0.4 and 0.6 ± 0.5 ng/ml, respectively. The basal and mean LH levels were therefore lower in short-day gilts ( P < 0.05), while LH pulse amplitude and frequency remained unaffected by treatment. In conclusion, the 6-week period under two different light regimes resulted in higher basal LH concentration in long-day gilts but was not able to produce changes in LH frequency in prepubertal gilts.

Assessment of Insulin Resistance in the Idiopathic Hirsutism

Background: Idiopathic hirsutism (IH) is the second most common cause of hirsutism, after polycystic ovary syndrome and occurs in about 15% of hirsute women. There are not many studies showing whether patients with IH also have insulin resistance. In the present study, we aimed to investigate the insulin sensivity in IH with non-obese and changing hormone levels during the hyperinsulinemic-euglycemic clamp. Methods: Twenty (20) non-obese women with IH (Group I) ranging in age from 20 to 30 (mean 25 ± 5) years were studied. Hirsutism in women with normal testosterone (T) levels and regular menstrual cycles is as defined IH. Twenty (20) healthy women (mean age 23 ± 2 years) (Group II) were included in this study as the control group. Insulin sensitivity was assessed with modified euglycemic insulin clamp technique. Samples of prolactin, luteinizing hormone (LH), follicle-stimulating hormone, adrenocorticotropic hormone (ACTH), dehydroepiandrosterone sulfate, cortisol, estradiol, progesterone, 17-OH progesterone (17-OHP), total T, and free T (FT) were obtained at baseline and at 2nd hour during clamp. Results: Steady-state (120 min) glucose disposal rates were higher in Group II than Group I (7.51 ± 0.83 vs. 5.76 ± 1.89 mg/kg/min). Mean FT, ACTH, cortisol, LH, prolactin and 17-OHP levels were found to have decreased statistically significantly (p < 0.05) in Group I. Mean FT, ACTH, and prolactin levels were found to have decreased statistically significantly (p < 0.05) in Group II during the clamp. Mean baseline levels of FT, LH and prolactin were greater in women with hirsutism than in the control subjects (p < 0.05). Insulin mediated glucose disposal was lower in the normal weight women with IH than in those without hirsutism. Conclusions: Mean FT, 17-OHP and dehydroepiandrosterone sulfate levels decreased during euglcemic-hyperinsulinemic clamp in IH.

Exposure to Urban Stressor and Effects on Luteinizing Hormone (LH) in Female Outdoor Workers

There are few studies in literature about exposure to urban pollutants and effects on female reproductive health. The aim of the study was to evaluate if the occupational exposure to chemical urban stressor could cause luteinizing hormone (LH) plasma levels alterations in female traffic police compared to a control group. One hundred and eighty subjects were included in the study, subdivided into three different groups according to the day of the menstrual cycle (7th, 14th, 21st) in which a blood sample was taken. In follicular and lutheal phase of ovarian cycle, the LH mean levels were significantly higher in traffic police vs. controls. The distribution of LH values in traffic police and controls was significant in follicular, and lutheal phase. In ovulatory phase, LH mean levels were lower but not significant in traffic police compared to controls. An increase was found concerning mental health disorders referred to the questionnaire items in traffic police vs. controls, although the difference was not significant. Our results suggest that occupational exposure to urban stressor in female traffic police, may alter LH plasma concentrations. LH may be used in occupational set as an early biomarker of exposure to urban stressor.

Role of Noradrenergic Receptors in the Bed Nucleus of the Stria Terminalis in Regulating Pulsatile Luteinizing Hormone Secretion in Female Rats

The bed nucleus of the stria terminalis (BNST) is one of the brain areas densely innervated by noradrenergic neurons originating in the brain stem. The present study aims to determine the role of noradrenergic receptors in the BNST in regulating pulsatile luteinizing hormone (LH) secretion in female rats. Ovariectomized (OVX) or estrogen-primed OVX (OVX+E2) rats received three 1-h-interval injections of 0.05 micromol of noradrenaline (NA), phenylephrine (alpha1-adrenergic receptor agonist), clonidine (alpha2-agonist), or isoproterenol (beta-agonist) into the BNST. Injection of NA or alpha1-adrenergic agonist into the BNST strongly suppressed pulsatile LH secretion in OVX+E2 rats with a significant (P < 0.05) decrease in the mean LH level for 3 h and LH pulse frequency, but alpha2-and beta-agonists did not affect any of the LH pulse parameters. In OVX animals, alpha1- and alpha2-adrenergic agonists caused a significant change in LH pulse frequency and amplitude, respectively, though the effect was not as apparent as the NA- or alpha1-agonist-induced changes in OVX+E2 animals. These results indicate that NA inputs to the BNST suppress pulsatile LH secretion via alpha1-adrenergic receptors and that estrogen enhances this suppression.

Sex Differences in the Neuroendocrine Response to Short‐Term Fasting in Rhesus Macaques

When energy intake is restricted in mammals, there are neuroendocrine adjustments in the secretion of reproductive and metabolic hormones to reallocate energy for vital functions. In the present study, we investigated whether there were differences in the luteinising hormone (LH), growth hormone (GH) and cortisol responses to a 48-h fast in adult gonad-intact male and female rhesus macaques. In both male and female macaques, blood glucose levels were significantly lower in fasted than in control studies, and levels were higher in males than in females. Male rhesus monkeys had significantly lower (P < 0.01) mean serum LH levels after a 48-h fast than under fed conditions and this was attributable primarily to a decrease in the amount of LH released during each secretory episode. In fasted females, serum LH levels were significantly greater (P < 0.05) than during the fed conditions but no differences were found in pulse amplitude or in the number of pulses. Almost twice as many GH pulses were observed in both males and females during fasting but there was no difference in either mean serum GH levels or pulse amplitude between control and fasted studies. A typical diurnal profile in cortisol levels was observed in both sexes and both experimental conditions. Under control conditions, male macaques released less cortisol than females, and although fasting increased mean cortisol levels in both males and females, only the males shown a significant rise over levels observed in control studies. The changes in plasma LH and cortisol levels in fasted rhesus macaques are similar to those observed in humans and suggest that gonadotrophin and corticotrophin secretion are more resistant to short-term energy deprivation in female than in male primates.

Recombinant Human Leptin in Women With Hypothalamic Amenorrhea

Hypothalamic amenorrhea, characterized by absent menstrual cycles and low estrogen levels, reportedly accounts for more than 30% of all cases of amenorrhea in women of reproductive age. Infertility and bone loss are possible consequences. Functional hypothalamic amenorrhea occurs when, for any reason, there is a relative energy deficit. Leptin levels are low in these patients, and the normal diurnal variation in leptin levels is absent. To determine whether low leptin levels cause neuroendocrine and reproductive dysfunction, 8 women with hypothalamic amenorrhea resulting from low body weight or strenuous exercise prospectively received recombinant human leptin for 2 to 3 months. Six control women received no treatment. Participants self-administered 0.08 mg/kg of recombinant human leptin subcutaneously each day, 40% of it in the morning and 60% in the evening. Serum leptin levels increased during treatment and body weight decreased slightly. Food intake and resting metabolic rate did not change appreciably. Three of 8 women had an ovulatory menstrual cycle while receiving leptin. Two others had a preovulatory follicle but did not ovulate. Leptin treatment significantly increased maximum follicle diameter, the number of dominant follicles, ovarian volume, and endometrial thickness. Mean levels of luteinizing hormone (LH) increased during treatment, and LH pulse patterns improved or became normal in 6 of 8 women. Thyroid hormone levels increased but remained within the normal range. Markers of bone formation, including bone alkaline phosphatase and osteocalcin, rose significantly during leptin treatment. There was no significant change in urinary N-telopeptides, a marker of bone resorption. Total bone density did not change significantly. No adverse effects were noted. Patients reported decreased appetite but felt well. In this prospective study, leptin treatment of women with hypothalamic amenorrhea normalized reproductive hormone levels, follicle development, and menstrual cyclicity. The findings suggest that leptin, which reflects the adequacy of stored energy, is necessary for normal neuroendocrine and reproductive functioning.

A short study in the treatment of hot flashes with buccal administration of 17-β estradiol

Objective: To assess the efficacy and safety of 17-β estradiol buccal tablets in reducing hot flush frequency (HFF) in postmenopausal women. Methods: Estradiol buccal tablets containing 0.05, 0.1, 0.2, or 0.4 mg or placebo were administered for 28 days to 99 postmenopausal women in a randomized, double-blind study; 19 premenopausal women were studied concurrently for comparison of laboratory data. Objective and subjective assessments of HFF were obtained along with measures of estradiol, estrone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). Results: Measurements of HFF revealed significant decreases from baseline in all estradiol groups ( P<0.01). In the 0.4 mg group, HFF decreased significantly compared to placebo ( P<0.01). All estradiol doses produced similar improvement in the vaginal maturation index. Mean serum estradiol levels increased as doses increased but were lower than in the premenopausal subjects. Mean serum FSH and LH levels decreased in all estradiol groups but not to the levels of the premenopausal subjects; the greatest decrease occurred at the two highest estradiol doses. Conclusion: A numerical dose–response relationship with hot flushes was seen in this pilot study comparing 0.05, 0.1, 0.2, and 0.4 mg buccal estradiol. Only 0.4 mg 17-β estradiol significantly reduced the occurrence of hot flushes compared to placebo.

Neuropeptide Y Gene Expression in Male Sheep: Influence of Photoperiod and Testosterone

The frequency of pulsatile release of gonadotropin-releasing hormone (GnRH) and luteinizing hormone (LH) is high in the breeding season and low in the nonbreeding season. These alterations in the patterns of GnRH and LH release are due to an interaction of daylength and gonadal steroid negative feedback. A vast amount of data indicates that steroid-responsive neural systems may play a role in regulating seasonal changes in GnRH release. One candidate system is neuropeptide Y (NPY). To determine the independent and interactive influences of photoperiod and steroid exposure on NPY mRNA levels, we used hypothalamic tissue from four groups (n = 4 per group) of castrated male sheep that were simultaneously housed in photochambers and exposed to: (1) a 16L:8D photoperiod (LD); (2) LD and implanted with testosterone (LD + T); (3) a 10L:14D photoperiod (SD), and (4) SD + T. Circulating levels of T averaged 2.8 ± 0.2 ng/ml in implanted animals, but were undetectable in nonimplanted males. Mean LH levels were significantly reduced (p < 0.01) in the LD + T group as compared with the other groups which did not differ from each other. The silver grain area per NPY neuron in the arcuate nucleus, as assessed by in situ hybridization, was inversely related to mean LH values, with the grain area per cell being significantly greater (p < 0.05) for LD + T males than for all other groups which did not differ from each other. NPY cell numbers were not significantly different (p > 0.10) among the treatment groups. These results show that NPY mRNA expression is increased in male sheep during a LD photoperiod in a T-dependent manner. Our data are consistent with the idea that NPY is involved in the seasonal regulation of GnRH and LH release in the male sheep.

Aromatase Inhibition Reduces Gonadotropin Dose Required for Controlled Ovarian Stimulation in Women With Unexplained Infertility

Obstetrical & Gynecological Survey: January 2004 - Volume 59 - Issue 1 - p 42-43 doi: 10.1097/01.OGX.0000102582.47985.5E

An eight-month clinical study of LA-2575 30.0 mg: a new 4-month, subcutaneous delivery system for leuprolide acetate in the treatment of prostate cancer

Objectives To investigate the safety, efficacy, and pharmacokinetics of a new 4-month subcutaneous depot of leuprolide acetate in patients with prostate cancer. Methods Ninety patients diagnosed with adenocarcinoma of the prostate were enrolled in an open-label, multicenter study. LA-2575 30.0 mg was administered subcutaneously once every 4 months for 8 months. The primary efficacy parameter was a serum testosterone level of 50 ng/dL or less. The pharmacokinetics of leuprolide acetate were analyzed in the first 24 enrolled patients. The values are reported as the mean ± standard error. Results Of 90 enrolled patients, 82 (91%) completed the 8-month study. Eight patients voluntarily withdrew from the study for the following reasons: nonmedical reasons (n = 3), treatment-related adverse events (n = 3), disease progression (n = 1), and cardiovascular disease (n = 1). By day 28, 85 (94%) of the 90 patients had achieved a serum testosterone level less than 50 ng/dL. At study completion, 88 (98%) of the 90 patients had a testosterone value less than the castrate level (mean 12.4 ± 0.8 ng/dL), with 81 (90%) at less than 20 ng/dL. From baseline to month 6, the mean luteinizing hormone level had decreased from 7.51 ± 0.69 mIU/mL to 0.12 ± 0.02 mIU/mL. The mean prostate-specific antigen level had decreased 90% from 13.2 ± 2.0 ng/mL at baseline to 1.3 ± 0.3 ng/mL at 8 months. No clinically significant flare reactions were observed. The most common treatment-related adverse event was mild hot flashes. Conclusions LA-2575 30.0-mg depot consistently produced and maintained safe and effective suppression of serum testosterone, with total serum testosterone concentrations well below the medical castrate level of less than 50 ng/dL.

The effect of pegylated human recombinant leptin (PEG-OB) on neuroendocrine adaptations to semi-starvation in overweight men

Starvation induces a complex neuroendocrine response in humans thought to have evolved to defend against reduced energy intake. The drop in leptin levels observed during fasting has been implicated as a factor that triggers this adaptive response. To explore this hypothesis, we executed a randomized, double-blind, placebo-controlled study to investigate whether elevated leptin levels using long-acting pegylated human recombinant leptin (PEG-OB) influenced the neuroendocrine responses to semi-starvation in human subjects. Twenty-four overweight male subjects (mean+/-s.e.m.; 34.8+/-1.3 yrs; 28.8+/-0.5 kg/m(2)) were prescribed a very low energy diet (2.1 MJ/day) to induce a state of semi-starvation for the next 46 days. In addition, all subjects received a weekly treatment of 80 mg PEG-OB or matching placebo. Hormone measurements were performed throughout the study period and included 5-h frequent hormone samplings and 24-h urine collections. Weekly subcutaneous administration of PEG-OB led to significant additional weight loss (2.8 kg) but it did not reverse the fasting-induced changes in the thyroid, corticotropic, somatotropic axes and sympathetic nervous system activity. However, after adjustment for weight loss, the drop in mean luteinizing hormone levels was attenuated in the PEG-OB group compared with the placebo group. These results suggest that a reduced level of leptin accompanying food restriction might be a component of the fasting-induced neuroendocrine inhibition of the human reproductive axis.

Gonadotropin treatment restores in vitro interleukin-1beta and tumour necrosis factor-alpha production by stimulated peripheral blood mononuclear cells from patients with idiopathic hypogonadotropic hypogonadism.

In the present study, we aimed to investigate the effects of testosterone deficiency and gonadotropin therapy on the in vitro production of tumour necrosis factor-alpha (TNF-alpha) and interleukin-1beta (IL-1beta) by peripheral blood mononuclear cells (PBMCs) from patients with idiopathic hypogonadotropic hypogonadism (IHH) in order to elucidate the modulatory role of androgen in cytokine production. Fifteen male patients with untreated IHH and 15 age-matched healthy male subjects were enrolled in the study. Serum follicle-stimulating hormone (FSH), luteinizing hormone (LH), free testosterone (FT), sex hormone binding globulin (SHBG), prolactin, and IL-2 and IL-4 levels were also measured. In unstimulated cultures, IL-1beta and TNF-alpha secretion were not significantly different between patient and control groups. However, after stimulation with lipopolysaccharide (LPS), secretion of IL-1beta and TNF-alpha was significantly higher in cultures from untreated patients with IHH than in control subjects. Mean FSH, LH and FT levels were significantly lower, whereas SHBG, IL-2 and IL-4 levels were significantly higher in patients with IHH compared than in controls. In patients with IHH, FT negatively affected the serum levels of IL-4 and in vitro secretion of IL-1beta and TNF-alpha. In addition, IL-2 and IL-4 affected the in vitro secretion of IL-1beta in a positive manner. Gonadotropin therapy decreased both TNF-alpha and IL-1beta in PBMCs from patients with IHH. The levels of serum IL-2 and IL-4 were also decreased by therapy. In conclusion, in the present study, gonadotropin treatment restored the in vitro production of IL-1beta and TNF-alpha by PBMCs from patients with IHH, suggesting that androgen modulates proinflammatory cytokine production, at least directly through its effects on PBMCs. It seems probable that this effect plays an important role in the immunosuppressive action of androgens.

Hormonal Characteristics in the Early Luteal Phase of Conceptive and Nonconceptive Menstrual Cycles

To determine whether serum hormone profiles are different in nonconceptive and conceptive menstrual cycles after ovulation and before implantation. Daily blood samples obtained during the luteal phase of nonconceptive cycles (n = 31) and conceptive cycles (n = 19) were analyzed (intersubject comparison). Samples obtained in sequential nonconceptive and conceptive cycles from five subjects (intrasubject comparisons) were analyzed to confirm results obtained with intersubject analysis. Serum luteinizing hormone (LH), follicle-stimulating hormone (FSH), estradiol (E(2)), progesterone, and relaxin were measured by immunoassay. A cell-based bioassay was used to determine whether the measurement of serum immunoreactive LH is a result of cross-reaction with human chorionic gonadotropin (hCG). Intersubject analysis showed that mean serum LH levels were significantly higher in conceptive cycles on day 4 and day 5 after the FSH peak in urine, and this was confirmed by intrasubject analysis. The addition of antibodies that precipitate hCG did not affect the activity of LH receptor ligand molecules in serum samples collected during the early luteal phase of conceptive cycles, as measured by bioassay. In contrast, this LH receptor binding activity was completely removed when precipitating antibodies for LH were added. The mean levels of serum E(2) were higher in conceptive cycles after day 4 following the FSH peak in urine. The mean values of serum FSH, progesterone, and relaxin were not significantly different in nonconceptive and conceptive cycles during the same time interval. The differences in luteal phase hormones may reflect alterations in signaling in the hypothalamic-pituitary-ovarian axis that begin during the preovulatory period of nonconceptive cycles.

The role of plasma renin activity in distinguishing patients with polycystic ovary syndrome (PCOS) from oligomenorrheic patients without PCOS

All the components of the renin-angiotensin system have been identified in the human ovary. Renin plays a major role in folliculogenesis, and possibly in follicular atresia. Polycystic ovary syndrome (PCOS)is characterized by early follicular atresia. We studied whether assessment of plasma renin activity would be useful for diagnosing PCOS and distinguishing PCOS and non-PCOS in oligomenorrheic patients.Patients were divided into three groups: PCOS group (group 1, n = 40), non-PCOS oligomenorrheic group (group 2, n = 30) and ovulatory control group (group 3, n = 30). Plasma renin activity was determinedin the early follicular phase of the menstrual cycle. Baseline serum levels of follicle stimulating hormone (FSH), luteinizing hormone (LH), prolactin, insulin, aldosterone and androgens (total testosterone,free testosterone, androstenedione, dehydroepiandrosterone sulfate and 17α hydroxyprogesterone) were determined in all groups. The mean LH level was lower (4.94 ± 4.65 mIU/ml) in control patientsthan in PCOS patients (12.9 ± 1.75 mIU/ml) and non-PCOS oligomenorrheic patients (10.8 ± 1.65 mIU/ml). There was no statistically significant difference between the groups regarding FSH levels.The mean plasma renin activity was 3.47 ± 0.29 ng/ml in the PCOS group. The mean plasma renin activity was 1.59 ± 0.21 ng/ml the non-PCOS oligomenorrheic group (statistically significiantdifferrence). There was no statistically significant difference between the non-PCOS oligomenorrheic (1.59 ± 0.21 ng/ml) and control groups (1.2 ± 0.16 ng/ml). Use of plasma renin activityalone as a diagnostic marker in PCOS is not useful, because the clinical findings of PCOS are heterogeneous and the pathogenesis is unclear. However, it can be used together with other variables to diagnosewomen with PCOS and to distinguish non-PCOS oligomenorrheic women from those with PCOS.

Dose‐dependent effects of melengestrol acetate (MGA) on plasma levels of estradiol, progesterone and luteinizing hormone in cycling heifers and influences on oestrogen residues in edible tissues

Melengestrol acetat (MGA) is widely used as a growth promoting feed additive in cattle breeding in the USA and several other non‐European countries. To explore the physiological effects of MGA four heifers were fed during 8 weeks with 0.5 mg MGA daily as registered in the USA and two heifers each received 0, 1.5 or 5 mg/day, respectively. Plasma samples were collected twice a week and concentrations of MGA, progesterone (P4) and estradiol‐17β (E2‐17β) were quantified. The pulsatile secretion of luteinizing hormone (LH) was investigated in 6‐hour profiles before and during treatment. After slaughter the reproductive organs were examined and oestrogen residues in edible tissues were measured. Four days after the beginning of MGA feeding MGA concentrations in plasma reached levels of 30 and 100–400 pg/mL depending on the dose received. Three weeks after the beginning of MGA feeding P4 plasma concentrations had dropped to base levels below 0.3 ng/mL in all three treatment groups. Mean plasma E2‐17β levels increased in physiological range from 1 to 5 pg/mL during 0.5 mg MGA/day feeding with many acyclic peaks. Overdosed MGA decreased E2 levels and suppressed cyclic peaks. Number and size of ovarian follicles were not altered by any treatment. Mean LH levels and pulse frequencies increased significantly during labelled treatment (0.5 mg/day), while higher doses had reducing effects. The development of corpus luteum was suppressed. E2‐17β residues in fat increased about 300% following labelled MGA treatment.

Effect of long-term feeding with graded levels of low glucosinolate rapeseed meal on endocrine status of gilts and their piglets

Seventy-two crossbred gilts of approximately 30 kg initial weight were used in this study. The gilts were divided into three groups and fed with graded levels of low glucosinolate rapeseed meal (RSM) over grower–finisher, gestation and lactation periods as follows C (control: no RSM in diet during growth/pregnancy/lactation), M-RSM (medium RSM levels: 7/2.5/7% RSM in diet equivalent to 0.45/0.16/0.45 mM glucosinolates/kg diet) and H-RSM (high RSM levels: 12/5/12% RSM in diet equivalent to 0.78/0.32/0.78 mM glucosinolates/kg diet). In experiment 1, the jugular veins of six gilts taken randomly from each group were cannulated. Blood was sampled every 4 h over 2 days during the midluteal phase of the first oestrous cycle. Plasma concentrations of free thyroxine (FT 4), triiodothyronine (T 3), luteinizing hormone (LH), prolactin (PRL), progesterone (P 4) and androstenedione (A 4) were determined. After sacrificing, thyroid glands, ovaries and uteri were dissected and weighed, the lengths of the uterine horns were measured, and the numbers of corpora lutea (CL) were counted. Thyroid glands of gilts fed H-RSM diet were heavier ( P<0.01) than those of control gilts. Diets containing RSM did not affect ovarian and uterine weights, CL numbers or uterine horn lengths. The mean plasma concentration of FT 4 decreased as the content of RSM in the diet increased. Plasma T 3 was lower ( P<0.001) in gilts fed M-RSM diet and plasma P 4 was higher ( P<0.01) in gilts fed H-RSM diet compared to control animals. The concentrations of A 4 and PRL in gilts fed diets containing RSM were significantly lower than those in controls. There were no significant differences in mean levels of LH among groups. In experiment 2, the remaining 54 gilts were mated to study the reproductive performance and endocrine status of their offspring. Thirty female piglets were randomly chosen from different litters in each of the three groups on the 2nd and 35th day of lactation (five piglets/per group/per day). The piglets were sacrificed and blood was sampled from the heart. Thyroids, ovaries and uteri were dissected and weighed. Samples of blood serum were assayed for FT 4, T 3, LH and PRL. The weights of thyroids, ovaries and uteri in female piglets were similar in all groups. The serum concentrations of FT 4, T 3, LH and PRL were not affected by the treatment, irrespective of the age of piglets (2nd or 35th day). In summary, long-term feeding with graded levels of low glucosinolate rapeseed meal did not result in significant alterations in reproductive performance of gilts. The RSM diets, however, did affect the mean concentrations of plasma FT 4, T 3, PRL P 4 and A 4 in gilts during the midluteal phase of the first oestrus cycle. In contrast, no significant differences in serum concentrations of examined hormones were found in piglets originating from control and RSM groups.

Influence of two low-dose oral contraceptives on pulsatile gonadotropin secretion

In this study ,we investigated the influence of two combined oral contraceptives on pituitary gonadotropin secretion and their pulsatile characteristics. The contraceptives compared were 30 μg ethinylestradiol plus 125 μg levonorgestrel; and 20 μg ethinyl estradiol plus 150 μg desogestrel. In 13 healthy normocyclic women ,hormonal patterns were obtained in the early follicular phase (EFP) andmid-luteal phase (MLP) of an ovulatory control cycle ,and on day 5/6 and day 20/21 of the first treatment cycle during a 12-hour period of continuous blood sampling. On the fifth day of treatment ,bothcombinations had significantly suppressed the mean levels of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). The LH pulse frequency of the treatment cycle was significantly inhibited incomparison with the EFP of the control cycle. While increased LH pulse amplitudes were observed on treatment day 5 for both combinations ,only the effects of the levonorgestrel-containing combination werefound to be significant. In all volunteers ,ovulation was reliably inhibited during the treatment cycle ,which was indicated by very low progesterone levels. Estradiol secretion was also suppressed on treatmentday 21.It is concluded that: (1) the pulsatile character of gonadotropin secretion is maintained at a low level during treatment with low-dose contraceptives; (2) the effects of the monophasic combinationson gonadotropin pulsatility do not seem to depend on the amount of ethinyl estradiol they contain.