Longitudinal Reproductive Hormone Profiles in Infants: Peak of Inhibin B Levels in Infant Boys Exceeds Levels in Adult Men1

The gonads are usually considered quiescent organs in infancy and childhood. However, during the first few postnatal months of life, levels of gonadotropins and sex hormones are elevated in humans. Recent epidemiological evidence suggests that environmental factors operating perinatally may influence male reproductive health in adulthood. The early postnatal activity of the Sertoli cell, a testicular cell type that is supposed to play a major role in sperm production in adulthood is largely unknown. Recently, the peptide hormone inhibin B was shown to be a marker of Sertoli cell function in the adult male. In the adult woman, inhibin B is secreted by the granulosa cells. Longitudinal serum levels of inhibin B were measured in healthy boys (n = 15) and girls (n = 15), in cord blood, and every third month during the first 2 yr of life. In addition, serum levels of FSH, LH, and testosterone (boys) were measured in the same group of children. In boys, inhibin B, FSH, LH, and testosterone levels were all elevated at 3 months of age. However, the peak of inhibin B was unexpectedly high, into the supraadult range (mean ± se, 378 ± 23 pg/mL) and persisted much longer than the elevation of FSH, LH, and testosterone. Thus, although levels of FSH, LH, and testosterone decreased into the range observed later in childhood by the age of 6–9 months, serum inhibin B levels remained elevated up to at least the age of 15 months. In girls, the hormonal pattern was generally more complex, with a high interindividual variation in levels of inhibin B, FSH, and LH within each age. In conclusion, the sustained elevation of inhibin B to supraadult levels in infant boys indicates that the neonatal period may be a developmental window important for Sertoli cell proliferation and maturation. Thus, the gonads may be potentially vulnerable to exogenous endocrine interference, e.g. from environmental factors during this period of life. Measurement of serum levels of inhibin B in infants may give clinical clues about developmental deficiencies in the gonads that otherwise only become apparent around puberty or later in life.

Download Full-text

Serum levels of insulin-like factor 3, anti-Müllerian hormone, inhibin B, and testosterone during pubertal transition in healthy boys: a longitudinal pilot study

Reproduction ◽

10.1530/rep-13-0435 ◽

2014 ◽

Vol 147 (4) ◽

pp. 529-535 ◽

Cited By ~ 21

Author(s):

Marie Lindhardt Johansen ◽

Ravinder Anand-Ivell ◽

Annette Mouritsen ◽

Casper P Hagen ◽

Mikkel G Mieritz ◽

...

Keyword(s):

Leydig Cell ◽

Cell Function ◽

Serum Levels ◽

Reproductive Hormones ◽

Inhibin B ◽

Testicular Volume ◽

Serum Concentrations ◽

Pubertal Onset ◽

Additional Information ◽

And Function

Insulin-like factor 3 (INSL3) is a promising marker of Leydig cell function with potentially high clinical relevance. Limited data of INSL3 levels in relation to other reproductive hormones in healthy pubertal boys exist. In this study, we aimed to evaluate longitudinal serum changes in INSL3 compared with LH, FSH, testosterone, inhibin B, and anti-Müllerian hormone (AMH) during puberty in healthy boys. Ten boys were included from the longitudinal part of the COPENHAGEN Puberty Study. Pubertal evaluation, including testicular volume, was performed and blood samples were drawn every 6 months for 5 years. Serum concentrations of testosterone were determined by a newly developed LC–MS/MS method, and serum concentrations of INSL3, AMH, inhibin B, FSH, and LH respectively were determined by validated immunoassays. The results showed that serum INSL3 levels increased progressively with increasing age, pubertal onset, and testicular volume. In six of the ten boys, LH increased before the first observed increase in INSL3. In the remaining four boys, the increase in LH and INSL3 was observed at the same examination. The increases in serum concentrations of LH, testosterone, and INSL3 were not parallel or in ordered succession and varied interindividually. We demonstrated that INSL3 concentrations were tightly associated with pubertal onset and increasing testicular volume. However, the pubertal increases in LH, INSL3, and testosterone concentrations were not entirely parallel, suggesting that INSL3 and testosterone may be regulated differently. Thus, we speculate that INSL3 provides additional information on Leydig cell differentiation and function during puberty compared with traditional markers of testicular function.

Download Full-text

New perspectives in the diagnosis of pediatric male hypogonadism: the importance of AMH as a Sertoli cell marker

Arquivos Brasileiros de Endocrinologia & Metabologia ◽

10.1590/s0004-27302011000800003 ◽

2011 ◽

Vol 55 (8) ◽

pp. 512-519 ◽

Cited By ~ 12

Author(s):

Romina P. Grinspon ◽

Rodolfo A. Rey

Keyword(s):

Sertoli Cell ◽

Cell Function ◽

Cell Activity ◽

Tanner Stage ◽

Inhibitory Effect ◽

Male Hypogonadism ◽

Fetal Life ◽

Infancy And Childhood ◽

Stimulation Tests ◽

Enzyme Defects

Sertoli cells are the most active cell population in the testis during infancy and childhood. In these periods of life, hypogonadism can only be evidenced without stimulation tests, if Sertoli cell function is assessed. AMH is a useful marker of prepubertal Sertoli cell activity and number. Serum AMH is high from fetal life until mid-puberty. Testicular AMH production increases in response to FSH and is potently inhibited by androgens. Serum AMH is undetectable in anorchidic patients. In primary or central hypogonadism affecting the whole gonad and established in fetal life or childhood, serum AMH is low. Conversely, when hypogonadism affects only Leydig cells (e.g. LHβ mutations, LH/CG receptor or steroidogenic enzyme defects), serum AMH is normal or high. In pubertal males with central hypogonadism, AMH is low for Tanner stage (reflecting lack of FSH stimulus), but high for the age (indicating lack of testosterone inhibitory effect). Treatment with FSH provokes an increase in serum AMH, whereas hCG administration increases testosterone levels, which downregulate AMH. In conclusion, assessment of serum AMH is helpful to evaluate gonadal function, without the need for stimulation tests, and guides etiological diagnosis of pediatric male hypogonadism. Furthermore, serum AMH is an excellent marker of FSH and androgen action on the testis.

Download Full-text

Serum inhibin B, FSH, LH and testosterone levels before and after human chorionic gonadotropin stimulation in prepubertal boys with cryptorchidism

Acta Endocrinologica ◽

10.1530/eje.0.1470095 ◽

2002 ◽

Vol 147 (1) ◽

pp. 95-101 ◽

Cited By ~ 31

Author(s):

P Christiansen ◽

AM Andersson ◽

NE Skakkebaek ◽

A Juul

Keyword(s):

Chorionic Gonadotropin ◽

Human Chorionic Gonadotropin ◽

Sertoli Cells ◽

Cell Function ◽

Serum Levels ◽

Inhibin B ◽

Seminiferous Tubules ◽

Bilateral Cryptorchidism ◽

Prepubertal Boys ◽

Baseline Levels

BACKGROUND: Several studies have indicated that cryptorchidism is associated with degenerative changes in both Sertoli cells and germ cells. The gonadal peptide hormone inhibin B reflects Sertoli cell function. Low inhibin B levels are found in a large portion of formerly cryptorchid men who show compromised seminiferous tubule function. It is not known if inhibin B can be used to demonstrate early damage of seminiferous tubules in prepubertal boys with cryptorchidism. METHODS: We investigated the relationship between serum levels of inhibin B, testosterone, FSH and LH in 62 prepubertal boys with uni- and bilateral cryptorchidism. Furthermore, we investigated the changes in serum levels of inhibin B and the corresponding changes in serum levels of FSH, LH and testosterone during a short course (3 weeks) of human chorionic gonadotropin (hCG) injections in 18 of these cryptorchid boys. RESULTS: In the 62 prepubertal boys with uni- or bilateral cryptorchidism there were no significant differences in baseline levels (median and range) of inhibin B (88 (20-195) pg/ml vs 78 (35-182) pg/ml; not significant), LH (0.08 (<0.05-0.99) IU/l vs 0.06 (<0.05-1.61) IU/l; not significant) and FSH (0.60 (0.08-3.73) IU/l vs 0.85 (0.25-2.55); not significant) compared with 156 healthy prepubertal boys, and there were no differences in hormonal levels between boys with uni- or bilateral cryptorchidism. There was no correlation between baseline levels of inhibin B and FSH. In boys younger than 9 years, we found no correlation between baseline levels of inhibin B and LH whereas, in boys older than 9 years, baseline levels of inhibin B were positively correlated to baseline LH (Spearman rank correlation coefficient ((R(s))=0.58, P=0.03). Treatment with hCG (1500 IU intramuscularly twice weekly for 3 weeks) resulted in descensus of testes in 9 out of 18 patients. In all boys but one, irrespective of age, hCG induced a marked increase in testosterone into the adult range (from undetectable to 21.8 (7.0-35.4) nmol/l; P<0.001) and completely suppressed FSH and LH levels. Serum levels of inhibin B increased significantly from 116 (50-195) pg/ml to 147 (94-248) pg/ml (P<0.05), but not uniformly. The increase in serum levels of inhibin B was inversely correlated to baseline inhibin B (Rs=-0.52, P=0.03) and baseline FSH (R(s)=-0.59, P<0.01). CONCLUSIONS: We therefore suggest that, in the prepubertal testes, inhibin B is secreted from the prepubertal Sertoli cells following hCG, whereas early pubertal testes with more differentiated Sertoli cells are not able to secrete inhibin B in response to hCG stimulation, perhaps due to lack of germ cell-derived betaB-subunits. We found (a) normal inhibin B levels in prepubertal boys with uni- or bilateral cryptorchidism, (b) that hCG stimulated testosterone markedly and suppressed FSH and LH levels and (c) that hCG treatment stimulated inhibin B levels in the youngest cryptorchid boys. In the oldest prepubertal boys no hCG-induced changes in inhibin B were shown.

Download Full-text

Factors affecting the secretion of immunoactive inhibin into testicular interstitial fluid in rats

Journal of Endocrinology ◽

10.1677/joe.0.1190315 ◽

1988 ◽

Vol 119 (2) ◽

pp. 315-326 ◽

Cited By ~ 17

Author(s):

R. M. Sharpe ◽

I. A. Swanston ◽

I. Cooper ◽

C. G. Tsonis ◽

A. S. McNeilly

Keyword(s):

Sertoli Cell ◽

Interstitial Fluid ◽

Positive Relationship ◽

Cell Function ◽

Local Heating ◽

Serum Levels ◽

Seminiferous Tubules ◽

Testosterone Levels ◽

Testicular Weight

ABSTRACT Immunoreactive inhibin was measured in testicular interstitial fluid (IF) from rats during sexual maturation or after impairment of spermatogenesis induced by ethane dimethanesulphonate (EDS), unilateral cryptorchidism or local heating (43 °C, 30 min) of the testes, to ascertain its usefulness as a marker of changing Sertoli cell function. Cultures of isolated seminiferous tubules were also studied. Inhibin was measured by a radioimmunoassay directed towards the first 26 amino acids of the N-terminus of the α-subunit, and the results confirmed for selected pools of IF by in-vitro bioassay using dispersed ovine pituitary cells. During puberty, IF levels of immunoactive inhibin fell by more than 90% (P<0·001) between 30 and 60 days of age, a decrease paralleled by the levels of androgen-binding protein (ABP), another Sertoli cell product secreted into IF. These changes also paralleled, but preceded, the fall (60%; P<0·001) in serum levels of FSH between 40 and 70 days, while the serum and IF levels of testosterone increased more than two-fold over this period. When adult rats were injected with EDS to destroy the Leydig cells, testosterone levels in IF and serum were undetectable at 3 and 7 days after treatment, were just detectable at 14 days and thereafter returned slowly towards normal by 42 days. The initial androgen withdrawal following EDS treatment caused a progressive reduction in testicular weight up to 21 days and this was accompanied by a significant increase in the serum levels of FSH and a two- to threefold increase in the IF levels of immunoactive inhibin (and also of ABP). Serum FSH and IF levels of immunoactive inhibin returned to within the normal range by 42 days when testosterone levels had normalized. In contrast, in two other experimental situations in which a marked decrease in testicular weight coupled with an increase in IF levels of ABP occurs, different results for the IF levels of immunoactive inhibin were obtained. Thus, in rats exposed to local heating of the testes, IF levels of immunoactive inhibin remained unchanged from control values at 21–40 days after treatment, a finding confirmed by bioassay results. In rats made unilaterally cryptorchid for 10 months, levels of immunoactive inhibin in IF were reduced by 60% (P<0·01) in the abdominal compared with the contralateral scrotal testis. These results suggest that (1) IF levels of immunoactive inhibin do not always change in parallel to the levels of ABP and may be a useful marker of changing Sertoli cell function, and (2) in at least two situations (puberty and after EDS treatment), there may be a positive relationship between the serum levels of FSH and the IF levels of immunoactive inhibin. This positive relationship was confirmed by in-vitro findings in which FSH and dibutyryl cyclic AMP (but not testosterone) were shown to stimulate immunoactive inhibin production by isolated rat seminiferous tubules during culture for 2–6 days. J. Endocr. (1988) 119, 315–326

Download Full-text

Anti-Müllerian hormone and inhibin B levels reflect altered Sertoli cell function in men with metabolic syndrome

Andrologia ◽

10.1111/j.1439-0272.2011.01185.x ◽

2011 ◽

Vol 44 ◽

pp. 329-334 ◽

Cited By ~ 15

Author(s):

R. Robeva ◽

A. Tomova ◽

G. Kirilov ◽

P. Kumanov

Keyword(s):

Metabolic Syndrome ◽

Sertoli Cell ◽

Cell Function ◽

Inhibin B

Download Full-text

439. GDF9 and BMP15 are germ-free regulators of Sertoli cell function

Reproduction Fertility and Development ◽

10.1071/srb08abs439 ◽

2008 ◽

Vol 20 (9) ◽

pp. 119

Author(s):

P. K. Nicholls ◽

C. A. Harrison ◽

R. B. Gilchrist ◽

P. G. Farnworth ◽

P. G. Stanton

Keyword(s):

Tight Junction ◽

Sertoli Cell ◽

Cell Cultures ◽

Cell Function ◽

Expression Patterns ◽

Seminiferous Epithelium ◽

Inhibin B ◽

Type I ◽

Female Reproduction ◽

Cell Functions

Oocyte-secreted Growth Differentiation Factor 9 (GDF9) and Bone Morphogenetic Protein 15 (BMP15) are critical regulatory factors in female reproduction. Together they promote granulosa cell proliferation and stimulate the maturation of preovulatory follicles. Despite their importance in female fertility, GDF9 and BMP15 expression patterns and function during spermatogenesis have not been investigated. In this study, we show that the expression and stage-specific localisation of both factors are limited to the germ cells of the rat seminiferous epithelium; with GDF9 being principally localised in round spermatids and BMP15 in gonocytes and pachytene spermatocytes. To identify potential cellular targets for GDF9 actions, cells of the seminiferous tubule were isolated and screened for the expression of the GDF9 and BMP15 signalling receptors (ALK5, ALK6, and BMPRII). Individual receptor types were expressed throughout the seminiferous epithelium, but co-expression of type I and type II receptors was limited to Sertoli cells and round spermatids. Based on the reproductive actions of related TGFβ ligands in the ovary and testis, GDF9 was assessed for its ability to regulate tight junction formation and inhibin B production in rat Sertoli cell cultures. When recombinant mouse GDF9 was added to immature Sertoli cell cultures, it inhibited membrane localisation of the junctional proteins claudin-11, occludin and ZO-1, thereby disrupting tight junction integrity. Concomitantly, GDF9 upregulated inhibin subunit expression and significantly stimulated dimeric inhibin B protein production. Together these results demonstrate that GDF9 and BMP15 are germ cell specific factors in the rat testis, and that GDF9 can modulate key Sertoli cell functions.

Download Full-text

Inhibin B plasma concentrations in infertile patients with DAZ gene deletions treated with FSH

Acta Endocrinologica ◽

10.1530/eje.0.1460801 ◽

2002 ◽

pp. 801-806 ◽

Cited By ~ 6

Author(s):

C Foresta ◽

A Bettella ◽

E Moro ◽

M Rossato ◽

M Merico ◽

...

Keyword(s):

Y Chromosome ◽

Sertoli Cell ◽

Germ Cells ◽

Sertoli Cells ◽

Cell Function ◽

Plasma Concentrations ◽

Inhibin B ◽

Azoospermia Factor ◽

Deleted In Azoospermia ◽

Factor C

OBJECTIVE: The DAZ (deleted in azoospermia) gene family on the Y chromosome long arm is the major candidate for the AZFc (azoospermia factor c) phenotype of male infertility and it is expressed only in germ cells. The aim of the study was to assess Sertoli cell function in subjects with AZFc deletions. DESIGN: Case-control, prospective study. METHODS: We have studied six severely oligozoospermic subjects with AZFc-DAZ deletions, and looked whether they responded in terms of inhibin B production to a 1 month FSH treatment. These patients were compared with three groups of patients affected by different spermatogenic alterations not related to deletions on the Y chromosome. RESULTS: Although affected by severe testiculopathy, patients with AZFc-DAZ deletions had only slightly elevated FSH, and normal inhibin B plasma concentrations. Inhibin B responded normally during FSH treatment, supporting the hypothesis that Sertoli cells are not altered. On the contrary, other severe testiculopathies not related to Y chromosome deletions showed high FSH and low inhibin B concentrations, with no response to FSH treatment. In these cases the cause of the spermatogenic defect probably damaged both germ and Sertoli cells. Finally, idiopathic patients with a hormonal status similar to Y-deleted patients (slightly elevated FSH and normal inhibin B concentrations) did not respond to FSH treatment, suggesting that Sertoli cells were already at their maximal functional capability. CONCLUSIONS: These data confirm that Sertoli cell function is not damaged in patients with AZFc-DAZ deletions and that the strong reduction of germ cells does not affect the FSH-inhibin B feedback loop.

Download Full-text