LH Levels (lh + level)

Distribution by Scientific Domains


Selected Abstracts


Symptomatic hypogonadism in male survivors of cancer with chronic exposure to opioids

CANCER, Issue 4 2004
Arun Rajagopal M.D.
Abstract BACKGROUND Profound hypogonadism has been noted in patients receiving intrathecal opioids. The purpose of the current study was to determine whether chronic consumption of oral opioids by male survivors of cancer also would lead to central hypogonadism and whether this hypogonadism was associated with symptoms of sexual dysfunction, fatigue, anxiety, and depression. METHODS A case,control study was conducted at The University of Texas M. D. Anderson Cancer Center (Houston, TX), in which 20 patients who were chronically consuming opioids were compared with 20 matched controls. Patients completed the Sexual Desire Inventory (SDI), the Hospital Anxiety and Depression Scale (HADS), the Functional Assessment of Chronic Illness Therapy with general and fatigue subscales (FACT-G/FACIT-F), and the Edmonton Symptom Assessment System (ESAS) questionnaires. Serum samples were collected for testosterone, follicle-stimulating hormone (FSH), and luteinizing hormone (LH). RESULTS Comparing the opioid group with the control group, 18 of the 20 patients (90%; 95% confidence interval [CI], 65,98%) exhibited hypogonadism, compared with 8 of the 20 control patients (40%; 95% CI, 19,64%). The median testosterone level was 145 ng/dL versus 399.5 ng/dL (5.0 nmol/L vs. 13.9 nmol/L; P < 0.0001), the median FSH level was 2.85 milli,International Units (mIU)/mL versus 5.3 mIU/mL (P = 0.08), the median LH level was 1.8 mIU/mL versus 4.2 mIU/mL (P = 0.0014), the median SDI-dyadic score was 18.5 versus 40 (P = 0.01), the median SDI-solitary score was 0 versus 5 (P = 0.007), the HADS (anxiety) score was 8.5 versus 5.5 (P = 0.053), the HADS (depression) score was 7.5 versus 1.5 (P = 0.0002), the FACT-G score was 64 versus 96.3 (P = 0.0001), and the FACIT-F score was 24 versus 46 (P = 0.0003). CONCLUSIONS Survivors of cancer who chronically consumed opioids experienced symptomatic hypogonadism with significantly higher levels of depression, fatigue, and sexual dysfunction. With the increasing use of opioids among patients with cancer, further research in improving quality-of-life outcomes is warranted. Cancer 2004;100:851,8. © 2004 American Cancer Society. [source]


Effects of unilateral laser-assisted ventriculocordectomy in horses with laryngeal hemiplegia

EQUINE VETERINARY JOURNAL, Issue 6 2006
P. ROBINSON
Summary Reasons for performing study: Recent studies have evaluated surgical techniques aimed at reducing noise and improving airway function in horses with recurrent laryngeal neuropathy (RLN). These techniques require general anaesthesia and are invasive. A minimally invasive transnasal surgical technique for treatment of RLN that may be employed in the standing, sedated horse would be advantageous. Objective: To determine whether unilateral laser-assisted ventriculocordectomy (LVC) improves upper airway function and reduces noise during inhalation in exercising horses with laryngeal hemiplegia (LH). Methods: Six Standardbred horses were used; respiratory sound and inspiratory transupper airway pressure (Pui) measured before and after induction of LH, and 60, 90 and 120 days after LVC. Inspiratory sound level (SL) and the sound intensities of formants 1, 2 and 3 (F1, F2 and F3, respectively), were measured using computer-based sound analysis programmes. In addition, upper airway endoscopy was performed at each time interval, at rest and during treadmill exercise. Results: In LH-affected horses, Pui, SL and the sound intensity of F2 and F3 were increased significantly from baseline values. At 60 days after LVC, Pui and SL had returned to baseline, and F2 and F3 values had improved partially compared to LH values. At 90 and 120 days, however, SL increased again to LH levels. Conclusions: LVC decreases LH-associated airway obstruction by 60 days after surgery, and reduces inspiratory noise but not as effectively as bilateral ventriculocordectomy. Potential relevance: LVC may be recommended as a treatment of LH, where reduction of upper airway obstruction and respiratory noise is desired and the owner wishes to avoid risks associated with a laryngotomy incision or general anaesthesia. [source]


CDP-choline increases plasma ACTH and potentiates the stimulated release of GH, TSH and LH: the cholinergic involvement

FUNDAMENTAL & CLINICAL PHARMACOLOGY, Issue 5 2004
Sinan Cavun
Abstract In the present study, we investigated the effect of intracerebroventricular (i.c.v.) administration of cytidine-5,-diphosphate (CDP) choline on plasma adrenocorticotropin (ACTH), serum growth hormone (GH), thyroid stimulating hormone (TSH), follicle stimulating hormone (FSH) and luteinizing hormone (LH) levels in conscious rats. The involvement of cholinergic mechanisms in these effects was also determined. In basal conditions, CDP-choline (0.5, 1.0 and 2.0 ,mol, i.c.v.) increased plasma ACTH levels dose- and time-dependently, but it did not affect the TSH, GH, FSH and LH levels. In stimulated conditions, i.c.v. administration of CDP-choline (1 ,mol, i.c.v.) produced an increase in clonidine-stimulated GH, thyrotyropin-releasing hormone (TRH)-stimulated TSH, LH-releasing hormone (LHRH)-stimulated LH, but not FSH levels. Injection of equimolar dose of choline (1 ,mol, i.c.v.) produced similar effects on hormone levels, but cytidine (1 ,mol, i.c.v.) failed to alter plasma levels of these hormones. Pretreatment with hemicholinium-3, a neuronal high affinity choline uptake inhibitor, (20 ,g, i.c.v.) completely blocked the observed hormone responses to CDP-choline. The increase in plasma ACTH levels induced by CDP-choline (1 ,mol, i.c.v.) was abolished by pretreatment with mecamylamine, a nicotinic receptor antagonist, (50 ,g, i.c.v.) but not atropine, a muscarinic receptor antagonist, (10 ,g, i.c.v.). The increase in stimulated levels of serum TSH by CDP-choline (1 ,mol, i.c.v.) was blocked by atropine but not by mecamylamine pretreatment. However, CDP-choline induced increases in serum GH and LH levels were greatly attenuated by both atropine and mecamylamine pretreatments. The results show that CDP-choline can increase plasma ACTH and produce additional increases in serum levels of TSH, GH and LH stimulated by TRH, clonidine and LHRH, respectively. The activation of central cholinergic system, mainly through the presynaptic mechanisms, was involved in these effects. Central nicotinic receptors solely mediated the increase in plasma ACTH levels while the activation of central muscarinic receptors was involved in the increase in TSH levels. Both muscarinic and nicotinic receptor activations, separately, mediated the increases in serum GH and LH levels after CDP-choline. [source]


Noradrenaline Involvement in the Negative-Feedback Effects of Ovarian Steroids on Luteinising Hormone Secretion

JOURNAL OF NEUROENDOCRINOLOGY, Issue 10 2009
C. V. V. Helena
Noradrenaline has been shown to modulate the ovarian-steroid feedback on luteinising-hormone (LH) release. However, despite the high amount of evidence accumulated over many years, the role of noradrenaline in LH regulation is still not clearly understood. The present study aimed to further investigate the involvement of noradrenaline in the negative-feedback effect of oestradiol and progesterone on basal LH secretion. In experiment 1, ovariectomised (OVX) rats received a single injection of oil, oestradiol, or progesterone at 09.00,10.00 h and were decapitated 30 or 60 min later. Levels of noradrenaline and its metabolite, 3-methoxy-4-hydroxyphenylglycol (MHPG), were determined in microdissections of the preoptic area (POA) and medial basal hypothalamus-median eminence (MBH-ME) and correlated with LH secretion. Basal LH levels were decreased 30 and 60 min after oestradiol or progesterone injection, and this hormonal response was significantly correlated with a reduction in POA MHPG levels, which reflect noradrenaline release. In addition, noradrenaline levels in the POA were increased, whereas noradrenaline turnover (MHPG/noradrenaline ratio) was decreased 60 min after the injection of both hormones. No effect was found in the MBH-ME. In experiment 2, i.c.v. administration of noradrenaline (60 nmol), performed 15 min before oestradiol or progesterone injection in jugular vein-cannulated OVX rats, completely prevented the ovarian steroid-induced inhibition of LH secretion. The data obtained provide direct evidence that LH secretion in OVX rats is positively regulated by basal noradrenergic activity in the POA, and its reduction appears to play a role in the negative-feedback effect of ovarian steroids on LH secretion in vivo. [source]


Central GABAA but not GABAB Receptors Mediate Suppressive Effects of Caudal Hindbrain Glucoprivation on the Luteinizing Hormone Surge in Steroid-Primed, Ovariectomized Female Rats

JOURNAL OF NEUROENDOCRINOLOGY, Issue 7 2005
S. R. Singh
Abstract The neurochemical mechanisms that link caudal hindbrain glucoprivic-,sensitive' neurones with the forebrain gonadotrophin-releasing hormone (GnRH)-pituitary luteinizing hormone (LH) axis remain unclear. Available studies indicate that the amino acid neurotransmitter, ,-aminobutyric acid (GABA), inhibits reproductive neuroendocrine function, and that caudal fourth ventricular administration of the glucose antimetabolite, 5-thioglucose (5TG), enhances GABA turnover within discrete septopreoptic structures that regulate LH secretion. The current experiments utilized the selective GABAA and GABAB receptor antagonists, bicuculline and phaclofen, as pharmacological tools to investigate whether one or both receptor subtypes function within neural pathways that suppress GnRH neuronal transcriptional activation and LH release during central glucose deficiency. During the ascending phase of the afternoon LH surge, groups of steroid-primed, ovariectomized female Sprague-Dawley rats were pretreated by lateral ventricular administration of bicuculline, phaclofen, or vehicle only, before fourth ventricular injection of 5TG or vehicle. The data indicate that, 2 h after 5TG treatment, Fos immunoexpression by rostral preoptic GnRH neurones and plasma LH levels were diminished relative to the vehicle-treated controls, and that inhibitory effects of 5TG on these parameters were attenuated by pretreatment with bicuculline, but not phaclofen. These results demonstrate that central GABAA, but not GABAB receptor stimulation during hindbrain glucoprivation, is required for maximal inhibition of reproductive neuroendocrine function by this metabolic challenge. The current studies thus reinforce the view that central GABAergic neurotransmission mediates regulatory effects of central glucoprivic signalling on the GnRH-pituitary LH axis. [source]


Serum ghrelin, leptin and resistin levels in adolescent girls with polycystic ovary syndrome

JOURNAL OF OBSTETRICS AND GYNAECOLOGY RESEARCH (ELECTRONIC), Issue 4 2008
Aysun Bideci
Abstract Aim:, The aim of the present study was to investigate the levels of leptin, resistin and ghrelin in polycystic ovary syndrome (PCOS), and to assess their possible correlations with the hormonal and metabolic features of PCOS. Methods:, Sixteen obese (ObPCOS) and 12 lean (LeanPCOS) subjects with PCOS and 19 obese control subjects were enrolled in the study. Results:, Ghrelin, leptin and resistin concentrations were similar between groups when body mass index (BMI) was used as a covariate (P > 0.05). Mean androgen, SHBG, luteinizing hormone (LH) levels and luteinizing hormone/follicle-stimulating hormone (LH/FSH) ratio tended to be similar between polycystic ovary syndrome (PCOS) groups. However, when compared with the control group, SHBG was lower and androgen, LH levels and LH/FSH ratio were higher in the PCOS groups. Free testosterone levels significantly correlated with resistin (r = ,0.38), SHBG correlated significantly with body mass index (BMI) (r = ,0.45) and resistin (r = ,0.67), LH/FSH ratio was significantly correlated with ghrelin (r = ,0.52) and estradiol (E2) levels (r = 0.51). Conclusion:, ObPCOS and LeanPCOS groups having higher LH/FSH ratios and lower SHBG levels suggest that there could be factors other than adiposity responsible for the clinical features of PCOS patients. In the light of our results, those factors can be suggested as ghrelin and E2 for the elevated LH/FSH ratio and resistin for the lowered SHBG. [source]


Brain Catalase Inhibition Blocks Ethanol-Related Decrease of Blood Luteinizing Hormone Levels in Mice

ALCOHOLISM, Issue 8 2002
Carles Sanchis-Segura
Background It has been demonstrated that ethanol decreases blood luteinizing hormone (LH) levels in rodents. This effect seems to be produced by the capacity of ethanol to release ,-endorphins from the hypothalamic arcuate nucleus and, in a second step, by a ,-receptor,mediated inhibitory effect of these peptides on hypothalamic LH-releasing hormone-synthesizing neurons. However, it has been reported that, in primary hypothalamic cultures, the ethanol-produced ,-endorphin release is mediated by the enzyme catalase. Therefore, the aim of this study was to assess whether catalase inhibition modifies ethanol effects on blood LH levels. Methods Swiss albino mice were pretreated with the catalase inhibitor 3-amino-1,2,4-triazole (AT; 0.0,0.5 g/kg) and, 3.5 hr later, saline, ethanol (2.5 g/kg), or morphine (30 mg/kg) was administered. Blood samples were collected 2 hr after ethanol administration, and LH levels were immunoenzymatically assayed. Results The catalase inhibitor AT dose-dependently blocked the ethanol-produced decrease in blood LH levels without altering those observed after saline or morphine administration. This effect was highly correlated with the decrease in brain catalase activity produced by AT. Conclusions These results show an antagonistic effect between AT and ethanol on blood LH levels and suggest a role of brain catalase activity on this effect of ethanol. Data are discussed in terms of a possible functional relationship between brain catalase and ,-endorphins in the mediation of some of the psychopharmacological consequences observed after ethanol administration. [source]


Predictive factors for organic central precocious puberty and utility of simplified gonadotropin-releasing hormone tests

PEDIATRICS INTERNATIONAL, Issue 6 2007
JIN-HO CHOI
Abstract Background: The aim of the present study was to determine whether the clinical presentation of patients with central precocious puberty (CPP) permits differentiation between idiopathic and organic forms, and to examine whether luteinizing hormone (LH) determination in single blood sample after gonadotropin-releasing hormone (GnRH) administration is sufficient to diagnose CPP. Methods: Potential clinical and laboratory predictors for the presence of central nervous system (CNS) abnormalities were assessed. Sensitivities and specificities of LH and follicle-stimulating hormone (FSH) levels at 0, 15, 30, 60, 90 and 120 min were compared after GnRH stimulation. Results: In 45 girls with signs of breast development, 26 were diagnosed as having CPP. The age of onset in patients with organic CPP was 4.75 ± 2.01 years (range 1.2,7.1 years, median 5.0 years), whereas the age in patients with idiopathic CPP was 7.09 ± 0.87 years (range 5.0,7.9 years, median 7.0 years). This parameter is the only one showing statistical significance. In addition, the specimen at 30 min after GnRH stimulation yielded highest sensitivity for the diagnosis of CPP. Conclusions: The earlier the onset of disease, the higher the possibility of presence of CNS lesion. According to the mean GnRH-stimulated LH levels and sensitivity at each time, a single blood sample obtained for LH determined after GnRH administration at 30 min can be used to diagnose CPP. [source]


Modulation of Ovarian Function in Female Dogs Immunized with Bovine Luteinizing Hormone Receptor

REPRODUCTION IN DOMESTIC ANIMALS, Issue 1 2002
BB Saxena
Adult female dogs were immunized with 0.5 mg bovine luteinizing hormone receptor (LH-R) encapsulated in a silastic subdermal implant and subsequently with four intramuscular booster injections of 0.1 mg LH-R each. Circulating LH-R antibody was detected in the sera 3 weeks post-implant. The appearance of LH-R antibody was associated with a decline in the serum progesterone concentrations to a range of 0,0.5 ng/ml until day 365 in the immunized dogs in comparison with a range of 5,10 ng in the control animals, suggesting a lack of ovulation and corpus luteum function in immunized dogs. The immunized dogs did not show signs of `standing heat' and failed to ovulate when induced by LH-RH challenge. Serum oestradiol levels, however, remained in the range of 30,40 pg/ml in both the immunized and the control dogs. With the decline in the antibody titres, the hormonal profile and vaginal cytology returned to a fertile state and the dogs exhibited signs of `standing heat', as well as vaginal bleeding. Dogs immunized with LH-R did not show any serious metabolic, local or systemic adverse effects. The hypothalamic,pituitary gonadal axis remained intact as indicated by little difference in pituitary LH levels between control and immunized animals, and by the release of LH by LH-RH challenge. These studies demonstrate that active immunization of female dogs with LH-R could immunomodulate ovarian function to cause a reversible state of infertility. It may be postulated that, due to extensive interspecies homology, a recombinant LH receptor-based immunocontraceptive vaccine may also be effective in other vertebrates. [source]


Seasonality of LH, testosterone and sperm parameters in spider monkey males (Ateles geoffroyi)

AMERICAN JOURNAL OF PRIMATOLOGY, Issue 5 2009
Ana Lilia Cerda-Molina
Abstract There are no reported data on hormonal fluctuations in black-handed spider monkey males. On previous research about the reproductive physiology of this monkey we have found that during the dry season females show ovulatory estrogen peaks and males present the best quality semen. As part of an ongoing research, in this study we assessed seasonal variations in the concentration of serum luteinizing hormone (LH) and testosterone (T) in three adult spider monkey males to corroborate the seasonal reproductive synchrony. At the same time sperm count and motility were evaluated to search for any correlation between those sperm parameters and hormonal concentrations. We took blood and semen samples (by electroejaculation) of anesthetized males throughout the rainy (June,September) and dry (October,May) months. Our results revealed that T and LH were higher throughout the dry season and there was a significant correlation between T concentration and sperm count. Although higher during the dry season, sperm motility tended to correlate with testosterone and LH levels. These results demonstrated that black-handed spider monkeys have a tendency to show a seasonal pattern of reproduction being the dry season the most likely time to achieve fertilization. Am. J. Primatol. 71:427,431, 2009. © 2009 Wiley-Liss, Inc. [source]


Low testosterone levels and unimpaired melatonin secretion in young males with metabolic syndrome

ANDROLOGIA, Issue 6 2006
R. Robeva
Summary The interrelations between testosterone, insulin and melatonin levels in males with metabolic syndrome (MS) are still not clarified, especially in young age groups. The aim of the present study was to compare the testosterone serum levels in young men with MS to those in healthy controls, and to determine the possible changes in their melatonin rhythm, as well as the relation between melatonin, insulin and lipid profile. Fasting insulin and testosterone concentrations were measured in 10 healthy nonobese and 10 MS patients. Blood samples for melatonin, insulin and luteinizing hormone (LH) were collected at 19.00, 03.00 and 11.00 hours. A significant difference was found between the testosterone levels in controls and patients. Luteinizing hormone levels in both groups were similar, however, higher night LH levels in MS patients were observed. No changes in the melatonin concentrations of the two groups were found. In conclusion, total testosterone levels were significantly lower in young men with MS compared with healthy age-matched controls. Mild hypoandrogenia in hyperinsulinaemic patients was not related with changes in their melatonin levels. No alterations in the endogenous melatonin rhythm of the MS patients were found. [source]


Effects of oestradiol on gonadotrophin levels in normal and castrated men

CLINICAL ENDOCRINOLOGY, Issue 6 2009
Willem De Ronde
Summary Context, Testosterone inhibits gonadotrophin release in men either directly or after aromatization to oestradiol. We hypothesized that in males the androgen receptor-mediated effect of testosterone on LH release is negligible relative to that of oestradiol. Objective, To compare the effect of experimentally induced variations of plasma oestradiol levels on LH levels in normal (physiological testosterone levels) and castrated men (very low testosterone levels). Design, Prospective, open label, intervention. Subjects and interventions, We suppressed endogenous oestradiol in 10 young men with letrozole 2·5 mg once daily. In these men and in 10 young healthy castrated men, we restored plasma oestradiol levels with oestradiol patches (first week 100 ,g/day, second week 50 ,g/day, third week 25 ,g/day and fourth week no oestradiol patch). Measurements, The effect of the intervention on plasma levels of LH were monitored and compared between the groups. Results, With the intervention, the mean plasma oestradiol level in the two groups varied from supraphysiological to below the lower reference range. Levels of LH mirrored plasma oestradiol levels in both the groups, as did testosterone in the intact group. Despite similar oestradiol levels, mean levels of LH were significantly higher in the castrated group compared to the intact group for all doses of oestradiol, and supraphysiological levels of oestradiol were unable to suppress LH into the physiological range in the castrated group. Conclusions, Physiological plasma oestradiol levels have a substantial suppressive effect on LH in men. However, low-normal testosterone levels are a prerequisite for suppression of LH into the normal range. [source]


Comparison of three doses of leuprolide acetate in the treatment of central precocious puberty: preliminary results

CLINICAL ENDOCRINOLOGY, Issue 5 2009
Verónica Mericq
Summary Objective, Depot luteinizing-hormone releasing hormone (LHRH) agonist have been widely used for the treatment of central precocious puberty (CPP), but the optimal doses to obtain hormonal suppression are still unknown, especially in patients with higher weights. The goal of our study was to compare the efficacy of three leuprolide acetate (LA) preparations, suppressing gonadotropin secretion in patients with CPP. Design, In an open 12-month protocol, we evaluated LA 7·5 mg/month, 11·25 and 22·5 every 3 months. Patients, Fourteen girls with CPP and weights over 30 kg. Measurements: Clinical, radiological and laboratory follow-up: GnRH test plus LH, FSH 40 min post analogue was performed periodically. Results, Pretreatment basal and LHRH stimulated LH levels between groups were not different. Basal and LHRH stimulated LH levels decreased significantly between baseline and from 3 up to 12 months of therapy in all groups (P = 0·001). GnRH stimulated LH peak <2 IU/l, the main efficacy criterion was met in 80, 75 and 100% of the children at 6 months in the 7·5, 11·25, 22·5 mg doses respectively. By 12 months, 100% of patients had LH suppressed to <2 IU/l. Conclusions These results affirm that 3-month injections may be a satisfactory alternative for the therapy of children with CPP to avoid monthly injections. In addition, suppression of LH occurs sooner in the 3-month 22·5 mg LA dose compared to the 3-month 11·5 mg; therefore, adequate dosing may be important for optimal outcome. Further investigation is needed in more patients over 30 kg, with longer treatment duration, and ultimately final height consideration. [source]


Gonadotrophin receptor blocking antibodies measured by the use of cell lines stably expressing human gonadotrophin receptors are not detectable in women with 46,XX premature ovarian failure

CLINICAL ENDOCRINOLOGY, Issue 3 2004
Massimo Tonacchera
Summary background, Premature ovarian failure (POF) is defined by cessation of ovarian function after puberty and before the age of 40. The syndrome is characterized by amenorrhoea, oestrogen deficiency and elevated levels of gonadotrophins. Autoimmunity has been proposed as a mechanism for some cases of destruction or malfunction of ovarian follicles. POF is often associated with type I and type II polyglandular autoimmune syndromes. It has also been postulated that receptors such as the LH and FSH receptors might become targets for blocking antibodies and such antibodies could be a cause of ovarian failure. patients and methods, Sixty-nine patients with POF isolated or associated with other endocrine autoimmune diseases (autoimmune thyroid diseases, Addison's disease, type 1 diabetes mellitus, multiple sclerosis, myasthenia gravis) were studied. All the patients had secondary amenorrhoea. The patient group had a median age of 33·1 years (range 15,57). Ovarian failure had been diagnosed at a median age of 29 years (range 15,39). The median time since diagnosis was almost 1 year but in six patients gonadal insufficiency had appeared 10,30 years earlier. All had a normal chromosomal karyotype (46, XX). Patients with POF were characterized by duration of amenorrhoea > 1 year, with elevated FSH and LH levels and undetectable or low oestrogen levels. Cell lines stably expressing recombinant human LH (CHO-LHr) and FSH (CHO-FSHr) receptors were prepared and used to search for antibodies able to inhibit LH- or FSH-stimulated cAMP production. Immunoglobulins extracted from sera of patients with POF were incubated with CHO-LHr and CHO-FSHr in the presence of human recombinant CG and FSH, respectively. results and conclusions, None of the immunoglobulin G (IgG) preparations from patients with POF was able to inhibit the activity of the FSH- and CG-stimulated cAMP production. [source]


FSH and ovarian response: spontaneous recovery of pituitary,ovarian activity during the pill-free period vs. exogenous recombinant FSH during high-dose combined oral contraceptives

CLINICAL ENDOCRINOLOGY, Issue 4 2002
A. M. Van Heusden
Summary ojbective Compare spontaneous recovery of pituitary,ovarian activity during the pill-free period following the correct use of low-dose oral contraceptives and subsequent ovarian function during the administration of exogenous recombinant FSH (recFSH) after switching to continued Lyndiol® (2·5 mg lynestrenol + 0·05 mg ethinyl-oestradiol) medication. design Prospective, randomized, group-comparative, single-centre study. Following the monitoring of the pill-free period (week 1) and subsequent treatment with Lyndiol® (for a total of 5 weeks), all subjects were randomly allocated to one of four groups receiving daily FSH injections for 1 week [75, 150, 225 IU recFSH or 150 IU purified urinary FSH (uFSH)] during the fourth week of Lyndiol® use. patients Thirty-six healthy volunteers aged 18,39 years, prestudy oral contraceptive use for at least 3 months, cycle length between 24 and 35 days. measurements Serum FSH, LH and oestradiol (E2) concentrations as well as transvaginal ultrasound assessment of the number and diameter of follicles > 2 mm were used to monitor pituitary ovarian function. results At the start of the pill-free period following the prestudy contraceptive medication, 67% of the women presented with LH and FSH levels < 1 IU/l and only one follicle > 10 mm was observed. Initial levels of LH and FSH correlated (P < 0·05) with the extent of pituitary,ovarian activity during the pill-free period. At the end of the pill-free period a follicle > 10 mm had emerged in one subject only. During the first 3 days of Lyndiol® use, seven women (19%) eventually showed at least one follicle > 10 mm. During combined exogenous FSH and Lyndiol® administration, LH levels remained completely suppressed (, 0·5 IU/l) in all women studied. FSH levels and number and size of follicles increased with increasing doses of exogenous FSH in a dose-dependent manner. E2 levels remained low in all groups (< 150 pmol/l). During the week following FSH administration, FSH levels and E2 levels decreased gradually while the number of follicles > 10 mm still increased. conclusions We have confirmed that dominant follicles > 10 mm are present at the end of the pill-free period and during the first days after resumption of pill intake. Once follicles > 10 mm arose at the end of the pill-free period, continued use of Lyndiol® did not reduce follicle diameters. One week of Lyndiol® reduces pituitary,ovarian activity to levels observed after 3 weeks of low-dose pills. FSH administration during Lyndiol® resulted in dose-dependent follicle growth despite extremely low LH levels. E2 secretion (56 ± 51 pmol/l) occurred to a limited and variable extent along with extremely low serum LH concentrations. Recovery of pituitary,ovarian activity at the end of the pill-free period is comparable to FSH levels and follicle dynamics following 7 days of 75,150 IU/l recFSH. [source]