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PubMed1986

Serum follicle stimulating hormone, luteinizing hormone, and testosterone in sexually stimulated intact and unilaterally castrated rams.

Ten two-year-old intact (IN) and unilaterally castrated (UC) Targhee rams were exposed to an estrogenized ewe each week from June to October. Each week the rams were subjectively evaluated for libido (10 for high interest and 1 for no interest). Semen was collected from all cooperating rams and evaluated for volume, concentration, and motility. Every 2 wk, blood samples were obtained at -30 and 0 min before and 30 and 60 min after ewe access. Serum was harvested; follicle stimulating hormone (FSH), luteinizing hormone (LH), and testosterone concentrations were quantified by radioimmunoassay (RIA). Week 5 of ewe access was assigned as Week 1. Libido scores rose from a low on Week 1, with eight rams ejaculating, to a high on Week 12, with all rams ejaculating (Week 1, 5.0 +/- 1.0; Week 12, 10.0 +/- 0.0). The product of testis length and width was significantly greater in UC compared with IN rams (88.4 +/- 1.4 versus 73.2 +/- 1.0 cm(2), respectively). Serum FSH concentrations (ng/ml) were greater (P < 0.05) in UC than IN rams and dropped over the experimental period. Serum LH concentrations (ng/ml) were significantly greater in UC compared with IN rams. This difference was more pronounced in Weeks 1 and 3 compared with Weeks 11 and 13. Serum testosterone concentrations (ng/ml) were similar in UC and IN rams throughout the experiment. In conclusion, serum testosterone was not altered in UC rams; however, serum FSH and LH concentrations were increased in UC rams. Unilateral castration did not enhance the normal changes in semen quantity and quality in the rams from July to October.

Journal Article↗
PubMed1986

Plasma and pituitary content of growth hormone luteinizing hormone, and prolactin in uremic rats. Effects of chronic infusion of insulin.

The influence of chronic renal failure on pituitary content and on serum concentrations of growth hormone (GH), prolactin (PRL), and luteinizing hormone (LH) was studied in chronically uremic rats by comparison with control rats fed ad libitum and diet-restricted rats pair-fed with uremic rats. A decrease of pituitary GH content was found in uremic and diet-restricted rats, in association with a normal circulating GH level. A decrease of pituitary PRL and LH content with respectively high and normal serum values was observed in uremic but not in diet-restricted rats. These data strongly suggest that GH disturbances are related to malnutrition, whereas PRL and LH abnormalities are related to the uremic state per se. As hypoinsulinemia was observed in uremic rats, and as insulin is largely implicated in growth, we have investigated the effects of chronic infusion of insulin, using miniosmotic pumps, on pituitary hormone content. In spite of normalization of circulating insulin levels in uremic rats treated with insulin, pituitary GH, LH, and PRL contents were unaffected. Thus, insulin deficiency did not appear to be responsible for the diminished pituitary reserve of these hormones.

Animals↗
PubMed1981

Serum levels of follicle stimulating hormone, luteinizing hormone, prolactin, testosterone, 5 alpha-dihydrotestosterone, 5 alpha-androstane-3 alpha, 17 beta-diol, 5 alpha-androstane-3 beta, 17 beta-diol, and 17 beta-estradiol from male beagles with spontaneous or induced benign prostatic hyperplasia.

The serum concentration of testosterone (T) 5 alpha-androstane-3 alpha, 17 beta-diol (3 alpha-diol), 5 alpha-androstane-3 beta , 17 beta-diol (3 beta-diol), luteinizing hormone (LH), follicle stimulating hormone (FSH), and prolactin in young (less than 40 months) beagles with spontaneous benign prostatic hyperplasia (BPH) were not significantly (P greater than 0.25) different from serum hormone levels of age matched controls, or old (greater than 60 months) beagles with BPH. However, the serum hormone levels of age matched controls, or with BPH (2.46 +/- 0.51 pg per ml) was significantly (P less than 0.05) lower than that of age matched controls (3.93 +/- 0.35 pg per ml) and of old beagles with BPH is not associated with increased serum concentrations of androgens, or changes in serum levels of gonadotropins, but may be related to some change in estrogen biosynthesis or metabolism. In the second part of the experiment, castrate and intact beagles were treated for 4 months with three weekly injections of T, DHT, 3 alpha-diol, estradiol, T + estradiol, DHT + estradiol, or 3 alpha-diol + estradiol. As expected, the serum concentration of T, DHT, 3 alpha-diol, estradiol, LH, and FSH varied dramatically depending on the steroid regimen used. Analysis of these results showed that prostate weight was increased by steroid treatments which elevated the serum DHT concentration. However, glandular hyperplasia, indistinguishable from that seen in dogs with BPH, occurred only when estradiol was added to those steroid treatments which caused elevated serum DHT concentration.

Androgens↗
PubMed1991

Relationship of oestrus synchronization method, circulating hormones, luteinizing hormone and prostaglandin F-2 alpha receptors and luteal progesterone concentration to premature luteal regression in superovulated sheep.

Ewes were treated with exogenous follicle-stimulating hormone (FSH) and oestrus was synchronized using either a dual prostaglandin F-2 alpha (PGF-2 alpha) injection regimen or pessaries impregnated with medroxy progesterone acetate (MAP). Natural cycling ewes served as controls. After oestrus or AI (Day 0), corpora lutea (CL) were enucleated surgically from the left and right ovaries on Days 3 and 6, respectively. The incidence of premature luteolysis was related (P less than 0.05) to PGF-2 alpha treatment and occurred in 7 of 8 ewes compared with 0 of 4 controls and 1 of 8 MAP-exposed females. Sheep with regressing CL had lower circulating and intraluteal progesterone concentrations and fewer total and small dissociated luteal cells on Day 3 than gonadotrophin-treated counterparts with normal CL. Progesterone concentration in the serum and luteal tissue was higher (P less than 0.05) in gonadotrophin-treated ewes with normal CL than in the controls; but luteinizing hormone (LH) receptors/cell were not different on Days 3 and 6. There were no apparent differences in the temporal patterns of circulating oestradiol-17 beta, FSH and LH. High progesterone in gonadotrophin-treated ewes with normal CL coincided with an increase in total luteal mass and numbers of cells, which were primarily reflected in more small luteal cells than in control ewes. Gonadotrophin-treated ewes with regressing CL on Day 3 tended (P less than 0.10) to have fewer small luteal cells and fewer (P less than 0.05) low-affinity PGF-2 alpha binding sites than sheep with normal CL. By Day 6, luteal integrity and cell viability was absent in ewes with prematurely regressed CL. These data demonstrate that (i) the incidence of premature luteal regression is highly correlated with the use of PGF-2 alpha; (ii) this abnormal luteal tissue is functionally competent for 2-3 days after ovulation, but deteriorates rapidly thereafter and (iii) luteal-dysfunctioning ewes experience a reduction in numbers of small luteal cells without a significant change in luteal mass by Day 3 and, overall, have fewer low-affinity PGF-2 alpha binding sites.

Animals↗
PubMed1985

Effect of follicular fluid treatment on follicle-stimulating hormone, luteinizing hormone and compensatory ovarian hypertrophy in prepuberal gilts.

Prepuberal 130-day-old gilts were treated with 10 ml of charcoal-stripped porcine serum (PS), whole porcine follicular fluid (WpFF) or charcoal-stripped pFF (CpFF) twice daily beginning the day before and continuing 8 days after unilateral ovariectomy (ULO). Follicle-stimulating hormone (FSH) declined for the first 14 h after ULO in WpFF and CpFF gilts and then by 24 h returned to values observed at or before ULO, whereas FSH was increased nearly twofold at 14 h in PS gilts. At 8 days after ULO the remaining ovaries from PS-treated gilts were heavier than ovaries from follicular fluid-treated gilts. In a second experiment, ovariectomized 130-day-old gilts were assigned to either a group infused with PS, a group infused with 5 ml CpFF, or a group infused with 10 ml Cpff at 18 and 2 h before a gonadotropin-releasing hormone (GnRH) challenge. Porcine follicular fluid had no effect on luteinizing hormone (LH) response to GnRH, depressed the FSH response to a 10-micrograms challenge of GnRH, but had no effect on FSH response to a 50-micrograms challenge of GnRH. In a third study, gilts were subjected to sham ovariectomy (Sham) or ULO at 130 days of age. GnRH (10 micrograms) was given on Days 1, 2 or 8 after surgery. The response to GnRH in ULO versus Sham gilts did not differ for FSH or LH on any day.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed2003

Inhibin B, follicle stimulating hormone, luteinizing hormone, and estradiol and their relationship to the regulation of follicle development in girls during childhood and puberty.

Inhibin B, produced by granulosa cells in the ovary, is a heterodimeric glycoprotein suppressing synthesis and secretion of the follicle stimulating hormone (FSH). The aim of the present study was to determine hormone profiles of inhibin B, FSH, luteinizing hormone (LH), and estradiol in girls during childhood and puberty and to evaluate whether inhibin B is a marker of follicle development. We examined the correlation between inhibin B and gonadotropins and estradiol during the first two years and across the pubertal development. Using a specific two-side enzyme-linked immunosorbent assay (ELISA), inhibin B levels were measured in the serum of 53 healthy girls divided into 8 groups according to age. In addition, serum FSH, LH, and estradiol were measured by chemiluminescent immunoassay in all serum samples. A rise in serum levels of inhibin B (55.2+/-7.3 ng/l, mean +/- S.E.M.) and FSH (1.78+/-0.26 UI/l), concomitant with a moderate increment of serum LH (0.36+/-0.09 UI/l) and estradiol (45.8+/-12.2 pmol/l) concentrations was observed during the first three months of life and declined to prepubertal concentrations thereafter. A strong positive correlation between inhibin B and FSH (r = 0.48, p<0.05), LH (r = 0.68, p<0.001) and estradiol (r = 0.59, p<0.01) was demonstrated during the first 2 years of life. A rise in serum levels of inhibin B, FSH, LH, and estradiol was found throughout puberty. Inhibin B had a strong positive correlation with FSH (stage I of puberty: r = 0.64, p<0.05; stage II of puberty: r = 0.86, p<0.01), LH (I: r = 0.61, p<0.05; II: r = 0.67, p<0.05), and estradiol (II: r = 0.62, p<0.05) in early puberty. From pubertal stage II, inhibin B lost this relationship to gonadotropins and estradiol. Serum inhibin B and FSH levels increased significantly during pubertal development, with the highest peak found in stage III of puberty (133.5+/-14.3 ng/l), and decreased thereafter. In conclusion, inhibin B is produced in a specific pattern in response to gonadotropin stimulation and plays an important role in the regulation of the hypothalamic-pituitary-gonadal axis during childhood and puberty in girls. Inhibin B is involved in regulatory functions in developing follicles and seems to be a sensitive marker of ovarian follicle development.

Adolescent↗
PubMed1978

Follicle-stimulating hormone, luteinizing hormone, and testosterone levels found in human seminal plasma.

Radioimmunoassays were performed on the seminal plasma of normospermic, oligospermic, and azoospermic men to determine the levels of luteinizing hormone (LH), follicle-stimulating hormone (FSH), and testosterone. FSH levels in the seminal plasma of all three groups were found to be similar to the levels normally found in blood serum. LH levels in the seminal plasma of azoospermic and oligospermic men were within the normal range found in blood serum but were elevated in the normospermic samples. Testosterone levels in the seminal plasma of all three groups tested were considerably lower than the normal range found in blood serum.

Follicle Stimulating Hormone↗
PubMedDate not supplied

Immunohistochemical localization of follicle-stimulating hormone, luteinizing hormone, growth hormone, adrenocorticotrophic hormone and prolactin in the human placenta.

The sites of localization of luteinizing hormone (LH), follicle-stimulating hormone (FSH), growth hormone (GH), adrenocorticotrophic hormone (ACTH) and prolactin (PRL) within placental tissues have been studied by an immunoperoxidase technique. The syncytiotrophoblast is the sole significant site of localization of LH, FSH, GH and ACTH; PRL is found both in syncytiotrophoblast and in decidual cells. It is highly probable that the sites of localization of these peptide hormones represents their sites of synthesis in the placenta and thus that the syncytiotrophoblast is the sole site of synthesis of LH, FSH, LH and ACTH. PRL appears to be synthesized both in syncytiotrophoblast and decidua, but the latter is probably not the major site of synthesis of this hormone. Whether these placental peptide hormones have any physiological role to play during pregnancy or whether the placental capacity to synthesize such hormones is an atavistic phenomenon of no functional importance is currently a moot point.

Adrenocorticotropic Hormone↗
PubMed2002

Modulation of growth hormone, luteinizing hormone, and testosterone secretion by excitatory amino acids in boars.

Ketamine hydrochloride, an n-methyl-d-aspartate (NMDA) receptor antagonist was used in an experiment that tested the hypothesis that fasting-induced increases in growth hormone (GH) secretion is mediated by excitatory amino acid (EAA) neurotransmission in boars. The effects of the drug on circulating concentrations of luteinizing hormone (LH) and testosterone were also evaluated. Blood was sampled at 15-min intervals for 8 h from 12 boars fitted with jugular vein catheters. At Hours 4 and 6, fasted boars (feed was withdrawn 48 h before the start of blood sampling) received i.m. injections of ketamine (19.9 mg/kg body weight; n=4) or .9% saline (n=4). Boars allowed feed on an ad libitum basis (n=4) received i.v. injections of n-methyl-d,l-aspartate (NMA; 2.5 mg/kg body weight), an NMDA receptor agonist, at Hours 4 and 6. Secretion of GH increased after NMA injections but was unaffected by treatment with ketamine or saline. Circulating concentrations of LH and testosterone were increased by injections of ketamine but were unaffected by injections of NMA or saline. Our results suggest that NMA is a potent GH secretagogue, but do not support the hypothesis that EAA neurotransmission drives the increased GH secretion displayed in fasted boars. Our finding that ketamine increased LH and testosterone release supports the notion that EAA have inhibitory effects on gonadotropin secretion in acutely fasted swine.

Animals↗
PubMed1985

Reevaluation of the relative activities of the pituitary glycoprotein hormones (follicle-stimulating hormone, luteinizing hormone, and thyrotrophin) from the green sea turtle, Chelonia mydas.

The discovery that the follicle-stimulating hormone (FSH) previously prepared from the green sea turtle, Chelonia mydas, contained a major neurohypophysial contaminant prompted a repurification and characterization of the glycoprotein hormones in this turtle. Results reaffirmed the physicochemical distinctiveness of the three hormones. Minimal cross-contamination between hormones (less than 2%) was achieved by ion-exchange chromatography, subunit dissociation (of contaminating luteinizing hormone (LH], gel filtration, and immuno-affinity chromatography. New preparations of FSH and thyrotrophin (TSH) derived from adult pituitaries proved to be more potent than those described previously (the degree depending on the nature of the assay); FSH showed the expected increase in activity based on estimated contamination of previous preparations. LH was similar to original preparations except for enhanced activity in FSH radioreceptor assays. Binding assays (in heterologous and homologous systems) again demonstrated the general absence of an FSH-specific receptor in the reptilian (chelonian and squamate) testes. In an in vivo bioassay in the lizard Anolis, the turtle FSH was orders of magnitude more potent than LH in stimulating both testis growth and androgen secretion, but in vitro LH was considerably more potent than FSH in stimulating androgen secretion in squamate and chelonian testes. Thus, the possibility exists that androgen secretion in some chelonian systems may exhibit a high degree of LH specificity like that of mammals and birds.

Androgens↗
PubMed1983

Age-related and seasonal variation in the Sertoli cell population, daily sperm production and serum concentrations of follicle-stimulating hormone, luteinizing hormone and testosterone in stallions.

Testes and blood samples were obtained from 201 stallions aged 6 months to 20 years in either December-January (nonbreeding season) or June-July (breeding season) to study the effect of age and season on reproductive parameters. Seasonal differences in the Sertoli cell population of adult (4-20 years old) horses were characterized by a 36% larger number of Sertoli cells in the breeding season than in the nonbreeding season. Seasonal elevation in the Sertoli cell population was associated with an increase in testicular weight and daily sperm production per testis (DSP/testis). Concentrations of luteinizing hormone (LH) and testosterone in serum varied with season. Although follicle-stimulating hormone (FSH) concentrations also tended to be higher in the breeding season, this trend was not statistically significant (P less than 0.08). Sertoli cell numbers averaged over both seasons, like testicular weights, increased with age until 4-5 years of age, but were stabilized thereafter. This age-related difference was also associated with increased concentrations of FSH, LH and testosterone, and with increased DSP/testis. The Sertoli cell population was capable of increasing in the adult horse by fluctuating its size with season. The number of elongated spermatids per Sertoli cell over both seasons increased with age up to 4-5 years of age and was stabilized thereafter. Thus, seasonal and/or age-related differences in DSP/testis were associated with significant elevations in serum concentrations of FSH, LH and testosterone, testicular weights, numbers of elongated spermatids per Sertoli cell and elevation of the Sertoli cell population.

Age Factors↗
PubMed1976

Serum follicle-stimulating hormone, luteinizing hormone and progesterone concentrations in pseudopregnant rats treated with medroxyprogesterone acetate.

Pseudopregnant rats were treated early in pseudopregnancy with 1 or 10 mg medroxyprogesterone acetate (MPA). Serum FSH, LH and progesterone concentrations were determined on days 2-20 of pseudopregnancy in treated and control rats. The mean duration of pseudopregnancy was 13-5 days in the control animals, but when animals were treated with 1 mg MPA a dioestrous period of 21-4 days was observed. A period with leucocytic vaginal smears of at least 2 months was observed after treatment with 10 mg MPA. Injection with MPA on day 3 of pseudopregnancy did not affect the serum FSH concentrations during the subsequent days. The progesterone pattern was alike in the three groups of animals, i.e. the duration of the activity of the corpora lutea was similar in all groups. However, 10 mg MPA slightly lowered progesterone concentrations on days 4-8 of pseudopregnancy. In the saline-treated rats, LH concentrations decreased from days 2-5, and remained low until they increased after day 11 of pseudopregnancy. This increase was delayed until day 20 in the animals treated with 1 mg MPA, and was not observed in the animals treated with 10 mg MPA. It is argued that the increase of LH concentration at the end of pseudopregnency is not instrumental in the decrease of peripheral progesterone concentration but rather that the decrease in the progesterone concentration leads to the increase in the LH concentration.

Animals↗
PubMed2000

Changes in concentrations of plasma immunoreactive follicle-stimulating hormone, luteinizing hormone, estradiol-17beta, testosterone, progesterone, and inhibin in heifers from birth to puberty.

This study was designed to clarify the characteristics of changes in plasma concentrations of reproductive hormones in heifers from birth to puberty. Weekly or daily hormonal changes were observed in 39 heifers. Daily changes in the concentration of follicle-stimulating hormone (FSH) demonstrated a consistent cycle of hormone changes over a 7- to 8-day period in heifers from approximately 10 days to 9 months old. Weekly changes in reproductive hormones showed that there were three brief periods in heifers between birth and puberty in which dramatic changes occur. The first period was the first week after birth, during which a reciprocal relationship between steroid hormones and gonadotropins was observed. At birth, the concentrations of steroid hormones were higher than those at any other age. These hormone levels rapidly decreased within the first week after birth. Gonadotropin levels, however, increased from birth to 1 week of age. The second period of major change was at approximately 4 weeks of age when there was an increase in the concentrations of luteinizing hormone (LH), estradiol-17beta, testosterone, and immunoreactive inhibin. The third period was the last 5 weeks before the first ovulation, when there was an increase in the concentrations of estradiol-17beta followed by an increase in (LH). These results suggest that regular hormone changes start from 10 days after birth and that the periods from birth to 4 weeks of age and the last 5 weeks before the first ovulation in heifers are important to the development of reproductive functions before puberty.

Animals↗
PubMed1991

Effects of neuropeptide Y on the in vitro release of gonadotropin-releasing hormone, luteinizing hormone, and beta-endorphin and pituitary responsiveness to gonadotropin-releasing hormone in female macaques.

The objectives of these studies were to examine the release of gonadotropin-releasing hormone (GnRH) and beta-endorphin-like activity (beta-EP) from macaque hypothalami, and the release of luteinizing hormone (LH) and GnRH-induced LH from macaque anterior pituitaries in response to neuropeptide Y (NPY) treatment. Anterior hypothalamic (AH) and mediobasal hypothalamic (MBH) blocks of tissues and the adenohypophysis were bisected along the midline into two equal-sized fragments. Fragments were superfused with medium for 3 h, followed by 3 h of either NPY (80 nM) or medium alone. In a separate experiment, adenohypophyseal (AP) fragments were superfused in accordance with the same protocol (3 h medium - 3 h NPY or medium) except that exogenous GnRH (352 nM) was added for 30 min at the beginning of hour 3 and again at the beginning of hour 6. Immunoactive GnRH, beta-EP, and LH levels were measured in superfusate samples (400 microliters) collected at 10-min intervals. GnRH levels rose within 20-30 min of initiation of NPY treatment, and elevated GnRH release was sustained for the duration of NPY exposure of both AH and MBH fragments from ovarian intact (INT) rhesus (Macaca mulatta: n = 8; p less than 0.05) or Japanese (Macaca fascicularis; n = 4; p less than 0.01) macaques. NPY treatment had no effect on either AH or MBH fragments isolated from ovariectomized (OVX) rhesus macaques (n = 4 for AH, and n = 5 for MBH). In AP fragments isolated from INT rhesus macaques (n = 8), NPY stimulated LH release within 1 h of treatment (p less than 0.05), whereas NPY had no effect on pituitaries from OVX animals (n = 4).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Changes of immunoreactive inhibin, follicle-stimulating hormone, luteinizing hormone, and progesterone in plasma after short-term food deprivation and during the ovulatory cycle of the domestic hen.

The interrelationship between immunoreactive inhibin and follicle-stimulating hormone (FSH) was measured in laying hens after short-term food deprivation and during the ovulatory cycle. Plasma inhibin was estimated by a heterologous radioimmunoassay validated for use in chicken. FSH was measured by a recently developed homologous radioimmunoassay. Ten hens were deprived of food for 10 days (a method to induce artificial moult or to stop egg laying). Blood samples were taken daily via the brachial vein for 10 consecutive days starting on the day of food withdrawal. The data are expressed in relation to the last day of oviposition. Short-term food deprivation, followed by ovarian atrophy, significantly depressed the plasma inhibin and progesterone (P4) concentration. Plasma FSH concentrations significantly increased, while luteinizing hormone (LH) concentrations slightly but not significantly decreased. In another experiment, 6 hens were induced to moult. The control hens (n = 6) were fed ad libitum. On Day 17, the hens were killed and follicular distribution was studied. The atrophy of the large yolky follicles in restricted hens was associated with a significant increase in the number of white follicles. In a third experiment, serial blood samples were taken from hens (n = 15) at 2-hr intervals for 36 hr via a brachial cannula. Plasma immunoreactive inhibin and FSH concentrations did not vary during the ovulatory cycle. LH and P4 increased simultaneously from basal levels to preovulatory peak values 6 hr before ovulation.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1999

The value of basal serum follicle stimulating hormone, luteinizing hormone and oestradiol concentrations following pituitary down-regulation in predicting ovarian response to stimulation with highly purified follicle stimulating hormone.

The value of gonadotrophin and oestradiol concentrations following pituitary down-regulation with leuprolide acetate in predicting ovarian response to stimulation was evaluated in three groups of women undergoing ovarian stimulation for in-vitro fertilization with highly purified follicle stimulating hormone (FSH). Leuprolide acetate was started in the midluteal phase, and either stopped at menses (IVF-SL group, n = 3), or continued throughout stimulation (IVF-LL group, n = 38; oocyte donors, n = 58). Ovarian stimulation was started on cycle day 3, after blood was drawn for down-regulated FSH, luteinizing hormone (LH) and oestradiol. Higher down-regulated LH was predictive of higher oestradiol on day 5 of stimulation in both IVF groups, and of need for fewer ampoules in the IVF-LL group, but not of oestradiol on day of human chorionic gonadotrophin (HCG) administration or number of oocytes retrieved. Higher FSH after down-regulation predicted yield of fewer oocytes in the donor and IVF-LL groups, and higher oestradiol on day 5 of stimulation, need for fewer ampoules and a shorter duration of therapy in both IVF groups. Higher oestradiol after down-regulation was associated with higher oestradiol on day 5 of stimulation and on day of HCG administration, a shorter duration of therapy and need for fewer ampoules in all groups. Whereas these results do not ascribe any predictive significance to LH, they suggest that oestradiol and FSH concentrations after down-regulation are predictive of the pattern of ovarian response to stimulation and of oocyte yield.

Adult↗
PubMed2003

Inhibin B, follicle stimulating hormone, luteinizing hormone and testosterone during childhood and puberty in males: changes in serum concentrations in relation to age and stage of puberty.

Inhibin B is a gonadal dimeric polypeptide hormone that regulates synthesis and secretion of follicle stimulating hormone (FSH) in a negative feedback loop. The aim of the present study was to determine changes in serum inhibin B, gonadotropins and testosterone concentrations during childhood and puberty in males. We studied the relationship between circulating inhibin B, gonadotropins and testosterone in serum of healthy boys during the first two years of life and then in pubertal development. Using a recently developed two-side enzyme-linked immunosorbent assay (ELISA), inhibin B levels were measured in the serum of 78 healthy boys divided into eleven age groups from birth to the end of pubertal development. In addition, serum levels of gonadotropins and testosterone were measured. Serum inhibin B, gonadotropins and testosterone increased during the first months of postnatal life. A peak in serum inhibin B and gonadotropins concentrations was observed around 3-4 months of age. There was a significant positive correlation between serum inhibin B and gonadotropins and testosterone levels during the first 2 years of life. After this early increase, serum inhibin B, gonadotropins and testosterone levels decreased significantly and remained low until puberty followed by an increase beginning with the onset of puberty. Serum levels of inhibin B reached a peak at stage G3 of puberty. Around midpuberty, inhibin B lost its positive correlation with luteinizing hormone (LH) and testosterone from early puberty, and developed a strong negative correlation with FSH, which persisted into adulthood. We conclude that inhibin B plays a key role in the regulation of the hypothalamic-pituitary-gonadal hormonal axis during male childhood and pubertal development. Inhibin B is a direct marker of the presence and function of Sertoli cells and appears to reflect testicular function in boys.

Aging↗
PubMed1997

Episodic variations of prolactin, thyroid-stimulating hormone, luteinizing hormone, melatonin and cortisol in infertile women with subclinical hypothyroidism.

Preliminary data have suggested that female infertility due to corpus luteum insufficiency may be caused by subclinical hypothyroidism [exaggerated thyroid-stimulating hormone (TSH) response to thyrotrophin-releasing hormone (TRH) stimulation]. L-Thyroxine supplementation has been recommended to achieve pregnancies in subclinical hypothyroid women. This controlled study was carried out in order to investigate the biochemical diagnosis of subclinical hypothyroidism as a possible infertility factor. Five infertile patients (aged 25-36 years) with subclinical hypothyroidism (n = 4, stimulated TSH >20 microU/ml) or primary hypothyroidism (n = 1) and five healthy controls (aged 22-39 years) with normal thyroid function (stimulated TSH <15 microU/ml), regular cycles and no history of infertility were studied in the early follicular phase. In the pre-study evaluation, eight of 23 volunteers (34.8%) had to be excluded because of subclinical hypothyroidism with stimulated TSH values (TSHs) >15 microU/ml. Cycle function of patients and controls was compared by the method of LH pulse pattern analysis. Therefore blood samples were drawn every 10 min during a 24 h period. Sleep was recorded from midnight to 7 a.m. Repetition of the TRH tests at the end of the 24 h blood sampling period confirmed the difference in stimulated TSH values of the two study groups. Pulse analysis for luteinizing hormone (LH), TSH and prolactin showed no differences between patients and controls for pulse frequency, amplitude, height, length, area under curve (AUC) and the 24 h mean. Even the hypothyroid patient had a normal LH pulse pattern. Additional measurement of melatonin in pooled sera every 30 min gave the well-documented diurnal profiles during day and night for both groups. Patients had significantly higher melatonin values at seven time points during the night. Peaks for LH, TSH, prolactin and cortisol were correlated with the sleep stages wake, rapid eye movement, 1 + 2 and 3 + 4. We concluded that corpus luteum insufficiency in female infertility cannot be explained by subclinical hypothyroidism and thus should not be treated with L-thyroxine for fertility reasons.

Adult↗