Effects of maternal exposure to low doses of DES on testicular steroidogenesis and spermatogenesis in male rat offspring.

Our previous studies have demonstrated that prenatally administered diethylstilbestrol (DES) impairs testicular endocrine function in male offspring. The present study examined whether maternal DES treatment influences testicular steroidogenesis and spermatogenesis. DES was injected subcutaneously at 0.5 or 1.5 microg/kg/day (DES 0.5 and 1.5 groups, respectively) into pregnant SD rats on days 7-21 of gestation. Male offspring in the DES 0.5 and 1.5 groups were autopsied at 1, 3, 6 and 15 weeks after birth. At 1 week, DES treatment did not lead to a change in the volume of P450scc-positive cells (Leydig cells), suggesting that DES has no inhibitory effect on the development of Leydig cells. DES administration disrupted luteinizing hormone receptor (LHr) expression and exerted inhibitory effects on signal transduction from LHr to steroidogenic acute regulatory protein (StAR) in testicular steroidogenesis (P<0.05), although there were no changes in the mRNA expression levels of steroidogenic enzymes, such as P450scc, 3beta-hydroxysteroid dehydrogenase (3beta-HSD) and P450(17 alpha), which may have caused a decrease in the plasma testosterone level. DES treatment did not disrupt the cycle of spermatogenesis but did upregulate the expression levels of androgen receptor (AR) mRNA in both DES groups at 15 weeks (P<0.05). These results indicate that maternal DES treatment disrupts steroidogenesis but induces a high level of AR mRNA expression to counteract the low levels of testosterone during spermatogenesis.

Müllerian inhibiting substance is an accurate marker of ovarian response in women of advanced reproductive age undergoing IVF.

While multiple investigators have demonstrated that Müllerian inhibiting substance (MIS) concentration is an accurate marker of ovarian reserve, all previous reports have focused on patients aged 36 and younger. It remains to be seen if MIS concentration is a useful marker in patients with the highest prevalence of diminished ovarian reserve: those aged 37 and over. Day 2 MIS concentrations in patients aged 37 and over undergoing IVF were examined, and the predictive value of MIS concentration was compared to that of FSH and oestradiol concentration. Three groups of patients were studied: (i) patients who experienced cycle cancellation; (ii) patients who underwent oocyte retrieval; (iii) patients who were precluded from IVF due to elevated FSH concentrations. While FSH and oestradiol concentrations were statistically similar in groups 1 and 2, MIS concentrations were significantly lower in group 1. In group 2, MIS concentration positively correlated with the number of oocytes retrieved. In group 3, 91% had low or undetectable MIS concentrations. The results indicate that MIS concentration accurately predicts cycle cancellation that is belied by normal FSH and oestradiol measurements, and has a better correlation with the number of oocytes retrieved than FSH and oestradiol measurements.

Serum and ovarian Müllerian inhibiting substance, and their decline in reproductive aging.

The objectives of this study were to identify whether there is a decline in Müllerian inhibiting substance (MIS) in the female rat during chronological aging, and to define the physiological basis of aging-related changes in MIS. The results demonstrate that there is an exponential decline in both serum and ovarian levels of MIS with increasing female age, and that the histologic origin for the reduction in serum levels of MIS is a decline in the number of small ovarian follicles expressing MIS.

Granulosa cell production of anti-Müllerian hormone is increased in polycystic ovaries.

CONTEXT: There has been renewed interest in anti-Müllerian hormone (AMH) because of its role in the ovary. Data on its actions are sparse, but it appears to inhibit follicle growth. Interestingly, serum AMH is two to three times higher in women with polycystic ovary (PCO) syndrome than women with normal ovaries. OBJECTIVE: We examined the production of AMH by cells from a range of follicle sizes from normal ovaries and compared this with production by ovulatory and anovulatory (anov) PCOs. DESIGN: Granulosa cells (GCs) and theca and follicular fluid (ff) were isolated from intact follicles. Cells were cultured for 48 h +/- FSH or LH, and AMH was measured in ff and cell-conditioned media (CM). RESULTS: AMH levels in ff and GC-CM ranged from 42 to 2240 and 0.025 to 1.7 ng/ml, respectively, and were low or undetectable in ff and GC-CM from follicles greater than 9 mm, luteinized cells, and theca and stroma. The mean level of AMH was four times higher in GC-CM from ovulatory PCOs [mean (range) 1.56 (0.025-7)] and 75 times higher from anovPCO [21.4 (17.2-43 ng/ml)] than normal ovaries [0.37 (0.025-1.7)]. Neither LH nor FSH had an effect on AMH production by GCs from normal ovaries, but in cells from PCOs, FSH significantly decreased AMH, and in contrast, LH increased AMH. CONCLUSIONS: The reduction of AMH in follicles greater than 9 mm from normal ovaries appears to be an important requirement for the selection of the dominant follicle. AMH production per GC was 75 times higher in anovPCOs, compared with normal ovaries. This increase in AMH may contribute to failure of follicle growth and ovulation seen in polycystic ovary syndrome.

Early postnatal methoxychlor exposure inhibits folliculogenesis and stimulates anti-Mullerian hormone production in the rat ovary.

Methoxychlor [1,1,1-trichloro-2,2-bis(4-methoxyphenyl) ethane; MXC] is a chlorinated hydrocarbon pesticide commonly used in the United States as a replacement for DDT [1,1,1-trichloro-2,2-bis(p-chlorophenyl)ethane]. While MXC is a weak estrogenic compound, its more active, major metabolite [2,2-bis(p-hydroxyphenyl)-1,1,1-trichloroethane; HPTE] shows estrogenic, anti-estrogenic, or anti-androgenic properties depending on the receptor subtype with which it interacts. Anti-Mullerian hormone (AMH) is a paracrine factor that suppresses initial follicle recruitment in the ovary. Studies have shown the effects of exposure to MXC on adult ovarian morphology and function. However, the effect of exposure to MXC at an early postnatal stage on pre-pubertal follicular development and ovarian AMH production has not been studied. Around postnatal day (P) 4, most of the primordial follicular assembly in rats is complete, and a large number of primordial follicles transition into the primary follicle stage, a process that is inhibited by estrogen. The objective of this study was to examine the effect of early postnatal (P3-P10) MXC exposure on ovarian morphology and size, follicle number, and AMH production in the pre-pubertal (P20) rat ovary and to investigate the effect of HPTE on AMH production in immature rat granulosa cells in vitro. Female rats were injected (s.c.) daily with vehicle (control) or 1, 10, 50, 100, or 500 mg MXC/kg per day (referred to here as 1MXC, 10MXC, and so forth.) between P3 and P10. On P20, uterine and ovarian weights were determined, ovarian histology was examined, and follicles were counted and classified into primordial, primary, secondary, pre-antral, or antral stages using the two largest serial sections at the center of the ovary. Ovarian AMH production was examined using immunohistochemistry and western blot analysis. The effect of HPTE (0.5-25 microM) on AMH production in cultured immature rat granulosa cells was determined by western blot analysis. Ovarian weight was reduced by 50, 100, and 500MXC (P < 0.01). MXC treatment inhibited folliculogenesis. Both 100 and 500MXC had a reduced number of antral follicles (P < 0.05) with a concomitant increase in pre-antral follicles (P < 0.05). Follicle numbers were not significantly affected by 1, 10, or 50MXC. Total follicle number and the number of primordial, primary, or secondary stage follicles were not significantly different in all treatment groups. Immunohistochemistry showed that MXC-treated ovaries had more AMH-positive follicles with stronger AMH immunostaining. Western blot analysis showed that AMH production was 1.6 +/- 0.2, 1.85 +/- 0.6, and 2.2 +/- 0.5 times higher in the 50, 100, and 500MXC ovaries as compared with the control ovaries respectively (P < 0.05). Granulosa cells treated with 1 or 5 microM HPTE had significantly greater AMH production (P < 0.05). These results demonstrate that MXC inhibits early ovarian development and stimulates AMH production directly in the rat ovary. In addition, HPTE was shown to stimulate AMH production in rat granulosa cells. Endocrine disruptors are widespread in the environment, and MXC represents a model endocrine disruptor due to the multiple actions of its metabolites. This study confirms that the endocrine disruptor MXC inhibits follicular development and demonstrates for the first time that MXC and HPTE directly stimulate AMH production in the ovary. This novel finding suggests that elevated AMH may play a role in MXC's inhibitory effect in the ovary.

Effect of whole-body 1800MHz GSM-like microwave exposure on testicular steroidogenesis and histology in mice.

The aim of our study was to evaluate the possible effects of whole-body 1800 MHz GSM-like microwave exposure on male reproduction. After repeated exposure of mice to microwaves at 0.018-0.023 W/kg whole-body specific energy absorption rate (SAR) an elevated serum testosterone level was measured, but no microwave exposure related histopathological alteration could be detected in the reproductive organs. The in vitro steroidogenic response of 48 h Leydig cell cultures obtained from exposed animals did not differ from the controls, suggesting that Leydig cells were not the primary targets of the applied microwave exposure or direct action of microwaves on Leydig cells was temporary only. In exposed animals the red blood cell count and volume of packed red cells were also increased. Further investigations are required to clarify the mechanism of action of the applied microwave exposure on male mice, as well as to establish the biological significance of the observed phenomena.

Anti-müllerian hormone protein expression is reduced during the initial stages of follicle development in human polycystic ovaries.

CONTEXT: Polycystic ovary syndrome, the most common cause of anovulatory infertility, is characterized by disordered folliculogenesis, notably increased progression from the primordial to the primary stages. This ovarian phenotype is similar to that observed in mice lacking anti-müllerian hormone (AMH). OBJECTIVE: The objective of this study is to investigate whether AMH is involved in accelerating the transition of follicles from primordial to primary stages in polycystic ovaries. DESIGN: This study compares AMH expression in archive tissue from normal and polycystic ovaries. SETTING: This is a laboratory-based study. PATIENTS: Ovarian tissue from seven normoovulatory women and 16 women with polycystic ovaries (five of whom were anovulatory) was used in this study. Ovaries were classified by histology and with reference to menstrual cycle history and ultrasound. MAIN OUTCOME MEASURE: Presence and intensity of AMH expression in 1403 follicles was the main outcome measure. RESULTS: AMH was observed from the primordial stage onward. AMH immunostaining was observed in significantly fewer primordial (P = 0.007) and transitional follicles (P = 0.001) in ovaries from anovulatory women with polycystic ovaries compared with women with regular cycles and either normal or polycystic ovaries. AMH-negative follicles had fewer pregranulosa cells in the largest cross-section of the follicle at both the primordial (median, four and six for AMH-negative and -positive follicles, respectively; P < 0.0001) and transitional stages (median six and nine; P < 0.0007) in normal tissue, and fewer at the transitional stage (median, seven and 11; P < 0.0001) in tissue from anovulatory women with polycystic ovaries. This suggests that AMH expression is associated with granulosa cell mitosis. CONCLUSIONS: These findings indicate a relative deficiency of AMH in primordial and transitional follicles in ovaries from anovulatory women with polycystic ovaries. This may contribute to disordered early follicle development in polycystic ovary syndrome.

Characterization and expression pattern of zebrafish Anti-Müllerian hormone (Amh) relative to sox9a, sox9b, and cyp19a1a, during gonad development.

The role of Anti-Müllerian hormone (Amh) during gonad development has been studied extensively in mammals, but is less well understood in other vertebrates. In male mammalian embryos, Sox9 activates expression of Amh, which initiates the regression of the Mullerian ducts and inhibits the expression of aromatase (Cyp19a1), the enzyme that converts androgens to estrogens. To better understand shared features of vertebrate gonadogenesis, we cloned amh cDNA from zebrafish, characterized its genomic structure, mapped it, analyzed conserved syntenies, studied its expression pattern in embryos, larvae, juveniles, and adults, and compared it to the expression patterns of sox9a, sox9b and cyp19a1a. We found that the onset of amh expression occurred while gonads were still undifferentiated and sox9a and cyp19a1a were already expressed. In differentiated gonads of juveniles, amh showed a sexually dimorphic expression pattern. In 31 days post-fertilization juveniles, testes expressed amh and sox9a, but not cyp19a1a, while ovaries expressed cyp19a1a and sox9b, but not amh. In adult testes, amh and sox9a were expressed in presumptive Sertoli cells. In adult ovaries, amh and cyp19a1a were expressed in granulosa cells surrounding the oocytes, and sox9b was expressed in a complementary fashion in the ooplasm of oocytes. The observed expression patterns of amh, sox9a, sox9b, and cyp19a1a in zebrafish correspond to the patterns expected if their regulatory interactions have been conserved with mammals. The finding that zebrafish sox9b and sox8 were not co-expressed with amh in oocytes excludes the possibility that amh expression in zebrafish granulosa cells is directly regulated by either of these two genes.

Germ-cell specific protein gametogenetin protein 2 (GGN2), expression in the testis, and association with intracellular membrane.

Gametogenetin (Ggn) is a germ cell-specific gene with multiple splicing variants giving rise to three predicted protein products, gametogenetin protein 1 (GGN1), gametogenetin protein 2 (GGN2), and gametogenetin protein 3 (GGN3). GGN1 and GGN3 were reported to interact with Fanconi anemia complementation group L (FANCL) per proliferation of germ cells (POG), a ubiquitin E3 ligase involved in germ-cell-deficient (gcd) mutation. While GGN2, another protein from Ggn by alternative splicing did not interact with FANCL/POG since it lacked the domain mediating the interaction. Little is known about the expression and function of GGN2. Here through Northern blotting experiment we showed that Ggn was mainly expressed in the testis but hardly detectable in the ovary or the somatic tissues. By preparing GGN2-specific antibody we showed that GGN2 was detectable and only detectable in the testis. By comparing the expression of Ggn mRNA and GGN2 protein in developing mouse testis, we showed that there was no evident delay of the translation of Ggn mRNA after their transcription. Both the subcellular localization study and the germ cell membrane protein fractionation implied that GGN2 associated with the intracellular membrane system. Co-fractionation on Superdex and yeast two-hybrids suggested that like GGN1, GGN2 was also a potential interaction partner of gametogenetin binding protein 1 (GGNBP1). Our data suggested that gametogenetin proteins were mainly involved in male germ cell development and GGN2 was also a possible interaction partner of GGNBP1. Like GGN1, GGN2 was also possibly involved in cell trafficking. The possible involvement of GGN2 in acrosome biogenesis was proposed.

Long-term effects of intrauterine exposure to mono-n-butyl phthalate on the reproductive function of postnatal rats.

PURPOSE: Although it is well known that phthalate esters induce testicular dysfunction in both adult and immature rats, there have been few reports on the long-term effect of phthalate esters on the testicular function of male rats exposed to phthalate esters in utero. This study was designed to assess the long-term effects of the mono-n-butyl phthalate (MBP) ester on the testicular function of neonatal and adult rat offspring from pregnant dams exposed to phthalate esters during gestation. METHODS: Pregnant rats were administered MBP [0.5 g/(kg body weight/.d); 4 days] by gavage from the 15th to the 18th gestational day. Rats administered solvent only were used as control subjects. After the rats' puberty, using male pups whose testes descended normally, the authors examined their fertility while also measuring their testicular weights, mean seminiferous tubular diameter, and the developmental grade of the germ cells (Johnsen score) in their testes. Next, in neonatal rats, the authors measured the testicular concentration of the Mullerian inhibiting substance (MIS) protein using enzyme-linked immunoassay and the expression level of the MIS messenger RNA using the quantitative polymerase chain reaction method as a marker of the Sertoli cells' function. Next the concentration of testosterone protein using a radioimmunoassay as a marker of the Leydig cells' function was measured. RESULTS: The pregnancy rate of the female rats coupled with MBP-treated male rats decreased significantly in comparison with that of the female rats coupled with control male rats (P < .01). Both the testicular weight and the Johnsen score in the MBP-treated group were decreased significantly more than those of the control group (P < .05). Neither the concentration of the MIS protein nor the expression level of the MIS messenger RNA in the MBP-treated neonatal testes differed from those of the control testes, whereas the concentration of testosterone protein in the neonate testes decreased significantly in the MBP-treated group in comparison with that of the control group (P < .01). CONCLUSIONS: A prenatal short-time exposure to MBP induces a long-term effect on postnatal rats and impairs reproductive function in male offspring probably by inhibiting the Leydig cells' rather than Sertoli cells' function in the fetal period.

Interleukin 1-beta injected into the testis acutely stimulates and later attenuates testicular steroidogenesis of the immature rat.

The effect of intratesticular administration of interleukin-1beta (IL-1beta) on steroidogenesis was studied in immature and adult rats. In 21-d-old animals local bilateral injection or unilateral administration of 0.1 microg/testis of IL-1beta to hemicastrates resulted in a significant increase in basal testosterone secretion in vitro and serum testosterone concentration one day posttreatment. Six days after treatment the cytokine induced opposite effect in animals with two testes in situ, i.e., it suppressed steroidogenesis. When IL-1beta was combined with hemi-castration, IL-1beta failed to alter the parameters studied. In adult animals subjected to bilateral treatment or to unilateral injection followed by hemicastration, IL-1beta in doses of 1.5 microg/testis or 15 microg/testis did not influence steroidogenesis and serum testosterone concentration. No change in serum LH and FSH concentration could be observed in any experimental group. The data suggest that the proinflammatory cytokine IL-1beta exerts a local action on testicular steroidogenesis, and the effect is age-dependent.

Effects of TCDD in modulating the expression of Sertoli cell secretory products and markers for cell-cell interaction.

Among different mammalian tissues, testis is found to be one of the most sensitive organs to TCDD exposure. In this study, primary Sertoli cell culture was established. The purity of the cultured cells was verified using 3beta-hydroxysteroid dehydrogenase, alkaline phosphatase as well as testosterone induction assays. Effects of TCDD in modulating the expression of CYP1A1, aromatase, secretory products (i.e. Mullerian inhibiting substance (MIS), 17beta-estradiol (E(2)) and lactate) and markers for cell-cell interaction (i.e. sertolin and testin) were then examined. Our data demonstrated that Sertoli cells exposed to 0.2-2000 pg/ml of TCDD showed a dose dependent induction of CYP1A1 mRNA. The minimal dose of activation was 2 pg/ml, which indicated that the cell was very sensitive to TCDD exposure. However, there was little or no detectable level CYP1A1 protein and EROD activities found. Dose-dependent inductions of aromatase transcript (200%) and E(2) (20%) secretion were measured. In addition there was a significant reduction (40%) of MIS mRNA. No detectable change in the level of secreted lactate was observed. Sertolin and testin, the gene makers for cell-cell interactions were differentially modulated upon TCDD treatment. Taken together, the results implicated that TCDD exposure might interfere with the normal Sertoli cell functions.

Enhanced purification and production of Müllerian inhibiting substance for therapeutic applications.

It is almost 60 years since Prof. Alfred Jost reported the seminal observations regarding Müllerian inhibiting substance (MIS). His experiments clearly showed that a testicular product other than testosterone, a Müllerian inhibitor, was responsible for Müllerian duct regression. Twenty-five years later Dr. Picon established an organ culture assay which paved the way for the initial studies into the biochemistry and biology of Müllerian inhibiting substance, also known as Anti-Müllerian hormone (AMH), undertaken first in Dr. Nathalie Josso's Laboratory in Paris then in our own laboratory in Boston. Purification of MIS led to cloning the human gene and production of recombinant human (rhMIS). MIS is a 140 kDa glycoprotein homodimer which is activated by a biosynthetic protease, cleaving MIS into an aminoterminus (110 kDa) and a carboxyterminus (25 kDa). The latter domain is sufficient for biological activities. MIS functions by interacting with two receptors; a type II binds the hormone and at type I that initiates downstream signaling. The MIS type II receptor has been cloned and functionally confirmed as distinct from that of other members of the TGFbeta superfamily. MIS can employ a number of type I receptors (ALK2, ALK3, ALK6) and BMP receptor specific SMADS 1, 5, and 8 in various tissue specific contexts. Cell lines derived from human ovarian, breast, and prostate tumors, and from rodent Leydig cell tumors, which respond to MIS in growth inhibition assays, all express the MIS type II receptor. A variety of signal transduction pathways are associated with the grown inhibition mediated by MIS. For example, breast and prostate cancer cell lines use a MIS-mediated NFkappaB pathway leading to G1 arrest and apoptosis. The ovarian cancer cell lines employ a pathway which enhances p16, modulates the E2Fs, and induces apoptosis. These signal transduction events can establish new rational treatment strategies to complement the growth inhibitory effects mediated by MIS. These combination strategies are being tested in vitro, and where appropriate will be tested in vivo using the highly purified MIS preparations, prior to use in early human clinical trials.

Exposure of neonatal rats to diethylstilbestrol affects the expression of genes involved in ovarian differentiation.

Exposing neonatal rats with the synthetic estrogen, diethylstilbestrol (DES), induces morphological and functional abnormalities in the adult ovary. We examined the events that lead to this condition using female rats that were exposed to DES for the first five days after birth. The expression of steroidogenic acute regulatory protein (StAR) and cholesterol side-chain cleavage cytochrome P450 (P450scc), which are both required for steroidogenesis in the theca/interstitial region was markedly reduced. The expression of Mullerian inhibiting substance (MIS) was transiently increased in small growing follicles in the ovary of DES-treated rats at postnatal day 7 (P7), and the expression profile in the ovary differed between DES- and vehicle oil-treated rats at P14 and P21. The expression of the transcription factor, steroidogenic factor-1 (SF-1), reduced in theca/interstitial cells, but increased in granulosa cells of primary follicles. These results indicate that altered steroidogenesis and MIS production are mechanisms through which DES induces abnormal ovarian development, and support the notion that androgens and MIS are both critical factors in regulating early ovarian differentiation.

Novel genes regulated by Sonic Hedgehog in pluripotent mesenchymal cells.

Sonic Hedgehog is a secreted morphogen involved in patterning a wide range of structures in the developing embryo. Disruption of the Hedgehog signalling cascade leads to a number of developmental disorders and plays a key role in the formation of a range of human cancers. The identification of genes regulated by Hedgehog is crucial to understanding how disruption of this pathway leads to neoplastic transformation. We have used a Sonic Hedgehog (Shh) responsive mouse cell line, C3H/10T1/2, to provide a model system for hedgehog target gene discovery. Following activation of cell cultures with Shh, RNA was used to interrogate microarrays to investigate downstream transcriptional consequences of hedgehog stimulation. As a result 11 target genes have been identified, seven of which are induced (Thrombomodulin, GILZ, BF-2, Nr4a1, IGF2, PMP22, LASP1) and four of which are repressed (SFRP-1, SFRP-2, Mip1-gamma, Amh) by Shh. These targets have a diverse range of putative functions and include transcriptional regulators and molecules known to be involved in regulating cell growth or apoptosis. The corroboration of genes previously implicated in hedgehog signalling, along with the finding of novel targets, demonstrates both the validity and power of the C3H/10T1/2 system for Shh target gene discovery.

The LIM-only coactivator FHL2 modulates WT1 transcriptional activity during gonadal differentiation.

An essential step during sex determination is the maintenance of the Müllerian duct in females and its regression in males caused by the expression of Müllerian inhibiting substance (MIS). In testes, the Wilms' tumor suppressor and the orphan nuclear receptor SF1 cooperatively bind to the promoter and activate transcription of MIS. In the ovaries, on the other hand, the orphan nuclear receptor DAX1 binds to SF1, inhibits transactivation by WT1/SF1 and thereby suppresses the induction of MIS expression. In addition, WT1 itself is responsible for the upregulation of DAX1 transcription. So far, little is known on which protein-protein interactions or cofactors elicit the spatiotemporal control of WT1-mediated transcription. Here we demonstrate coexpression of the LIM-only coactivator FHL2 and WT1. FHL2 and WT1 functionally interact both in vitro and in vivo. The importance of this interaction is revealed by the ability of FHL2 to potentiate the synergistic induction of MIS gene expression by WT1/SF1. Moreover, FHL2 coactivates transactivation of the DAX1 promoter by WT1. Hence, we present FHL2 as a novel transcriptional coactivator of WT1. The ability to modulate both DAX1 and MIS expression might allow FHL2 to act in the molecular fine tuning of WT1-dependent control mechanisms in the reproductive organs.

Early follicular serum müllerian-inhibiting substance levels are associated with ovarian response during assisted reproductive technology cycles.

OBJECTIVE: To test the hypothesis that the concentration of early follicular phase serum müllerian-inhibiting substance (MIS) is associated with ovarian response in women undergoing ovulation induction in preparation for assisted reproductive technology (ART). DESIGN: Retrospective analysis of frozen day 3 serum samples. SETTING: Academic ART program. PATIENT(S): One sample of frozen day 3 serum from women with < or = 6 retrieved oocytes (n = 28) compared with women with > or = 11 oocytes retrieved (n = 79) in preparation for IVF. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): Comparison of day 3 serum MIS levels between two groups of women. Other comparisons included maximum serum E(2) concentrations, number of retrieved oocytes, and percentage of mature oocytes between groups. RESULT(S): Mean serum MIS concentrations were 1.0 +/- 0.4 ng/mL compared with 2.5 +/- 0.3 ng/mL, or more than a 2.5-fold greater serum concentration of MIS in the group with > or = 11 oocytes retrieved compared with in the group with < or = 6 retrieved oocytes. CONCLUSION(S): These data demonstrate an association between early follicular phase serum MIS and the number of retrieved oocytes. Higher day 3 serum MIS concentrations were associated with greater number of retrieved oocytes.

Antimüllerian hormone serum levels: a putative marker for ovarian aging.

OBJECTIVE: To investigate whether serum concentrations of antimüllerian hormone may be used as a marker for ovarian aging. DESIGN: Longitudinal observational study. SETTING: Academic research center. PATIENTS: Forty-one normo-ovulatory premenopausal women and 13 healthy postmenopausal women. MAIN OUTCOME MEASURE(S): Concentrations of serum antimüllerian hormone (assessed on two occasions 2.6 +/- 1.7 years apart), FSH, inhibin B, and estradiol and number of ovarian follicles on ultrasonography. RESULT(S): Concentrations of antimüllerian hormone decreased significantly over time (median value, 2.1 microg/L [range, 0.1-7.4 microg/L] at visit 1 vs. 1.3 microg/L [range, 0.0-5.0 microg/L] at visit 2), whereas the number of antral follicles and levels of FSH and inhibin B did not change. During visits 1 and 2, concentrations of antimüllerian hormone correlated with age (r = -.40, P=.01 and r = -.57, P<.001, respectively); number of antral follicles (r =.66, P<.001 and r =.71, P<.001); and, to a lesser extent, with FSH level (r = -.29, P=.07 and r = -.37, P<.05) but not with inhibin B levels. CONCLUSION(S): Serum concentrations of antimüllerian hormone decreased over time in young normo-ovulatory women, whereas other markers associated with ovarian aging did not change. Concentrations of antimüllerian hormone correlate with the number of antral follicles and age and less strongly with FSH level. Concentrations of antimüllerian hormone may be a novel marker for ovarian aging.

Anti-Müllerian hormone and its receptors.

Anti-Müllerian hormone (AMH), a member of the transforming growth factor-beta family, is an important factor of male sex differentiation. It is produced by Sertoli cells from the time of fetal sex differentiation to puberty. AMH is also produced by granulosa cells from the time of birth to the end of ovarian activity. As other members of the transforming growth factor-beta family, AMH signals through two related but distinct receptors, both serine/threonine kinases with a single transmembrane domain, called type II and type I. The type II receptor has been cloned in 1994 and is expressed solely in AMH target organs. Engagement of the type I receptor BMPR-IB and downstream effector Smad1 by AMH has recently been demonstrated, however, its role in AMH biological actions remains to be proven.