Many well-trained athletes, ballet dancers and women who diet excessively have secondary or primary amenorrhoea. Less extensive training or weight loss may result in anovulatory menstrual cycles, or a shortened luteal phase. These disruptions of reproductive ability are due to hypothalamic dysfunction, which is correlated with weight loss or excessive leanness. It is proposed that these associations are causal and that the high percentage of body fat (26-28%) in the mature human female may influence reproduction directly. Four mechanisms are known: (i) adipose tissue converts androgens to oestrogen by aromatization. Body fat is thus a significant extragonadal source of oestrogen; (ii) body weight, hence fatness, influences the direction of oestrogen metabolism to more potent or less potent forms; leaner women make more catechol oestrogens, the less potent form; (iii) obese women and young, fat girls have a diminished capacity for oestrogen to bind sex-hormone-binding-globulin; (iv) adipose tissue can store steroid hormones. An indirect mechanism may be signals of abnormal control of temperature and changes in energy metabolism, which accompany excessive leanness. The hypothalamic reproductive dysfunction results in abnormal gonadotrophin secretion: there is an age inappropriate secretory pattern of luteinizing hormone (LH) and follicle stimulating hormone (FSH), resembling that of prepubertal children. The secretion of LH and the responses to LHRH are reduced in direct correlation with the amount of weight loss. Other evidence from non-athletic and athletic women and mammals is presented in support of the hypothesis that a particular, minimum ratio of fat to lean mass is normally necessary for menarche (approximately 17% fat/body wt) and the maintenance of female reproductive ability (approximately 22% fat/body wt). Nomograms are given for the prediction of these critical weights for height from a fatness index; these weights are useful clinically in the evaluation of nutritional amenorrhoea and the restoration of fertility in underweight women. Evidence is presented that undernutrition and hard physical work can affect the natural fertility of populations, by the delay of menarche, a longer period of adolescent subfecundity, a longer birth interval and an earlier age of menopause. Data from a study of the long-term reproductive health of 2622 former college athletes compared with 2766 non-athletes show that the former college athletes had a significantly lower lifetime occurrence of breast cancer and cancers of the reproductive system, and a lower lifetime occurrence of benign tumours of these tissues, compared with the non-athletes.(ABSTRACT TRUNCATED AT 400 WORDS)

OBJECTIVE

To evaluate the dietary calcium and vitamin D status in south Indian postmenopausal women.

METHODS

Postmenopausal women (n = 164) were evaluated for their daily dietary calcium intake, phytate to calcium ratio, and bone mineral parameters. Their serum leutinizing hormone (LH), follicle-stimulating hormone (FSH), 25-hydroxyvitamin D (25[OH]D), and parathyroid hormone levels (PTH) were measured.

RESULTS

Their age and BMI were 59.5 +/- 8 years and 27 +/- 5 kg/m2, respectively. Their daily dietary intake of calcium was 323 +/- 66 mg/day; phytate to calcium ratio, 0.56+/-0.1; LH, 26 +/- 13.5 microIU/l; and FSH, 62.6 +/- 30 microIU/l. Their dietary intake of calcium was low compared with the recommended daily/dietary allowance (RDA) of the Indian Council of Medical Research (ICMR) for the Indian population. Of the 164 patients studied, based on population-based reference values, 126 (77%) had normal 25(OH)D levels (9-37.6 ng/ml), and 38 (23%) had 25(OH)D deficiency. Using functional health-based reference values, 30 (18%) patients had normal 25(OH)D levels >> 20 ng/ml), 85 (52%) had 25(OH)D insufficiency (10-20 ng/ml), and 49(30%) had 25(OH)D deficiency (< 10 ng/ml). PTH and serum alkaline phosphatase (SAP) was significantly high in patients with 25(OH)D deficiency (p < 0.05) compared with those with normal 25(OH)D levels. There was a negative correlation between 25(OH)D and PTH (r = -0.2; p < 0.007) and SAP (r = -0.2; p < 0.001). Dietary calcium correlated positively with dietary phosphates (r = 0.8; p < 0.001) and phytate to calcium ratio (r = 0.75; p < 0.001).

CONCLUSIONS

Population-based reference values underdiagnosed vitamin D insufficiency and overdiagnosed normal vitamin D status. The diet was insufficient in calcium and high in phytate. About 82% of the study group had varying degrees of low 25-hydroxyvitamin D levels. The quality of diet has to be improved with enrichment/supplementation of calcium and vitamin D to suppress secondary hyperparathyroidism-induced bone loss and risk of fractures.

The precise interplay of hormonal influences that governs gonadotropin hormone production by the pituitary includes endocrine, paracrine and autocrine actions of hypothalamic gonadotropin-releasing hormone (GnRH), activin and steroids. However, most studies of hormonal regulation of luteinizing hormone (LH) and follicle-stimulating hormone (FSH) in the pituitary gonadotrope have been limited to analyses of the isolated actions of individual hormones. LHbeta and FSHbeta subunits have distinct patterns of expression during the menstrual/estrous cycle as a result of the integration of activin, GnRH, and steroid hormone action. In this review, we focus on studies that delineate the interplay among these hormones in the regulation of LHbeta and FSHbeta gene expression in gonadotrope cells and discuss how signaling cross-talk contributes to differential expression. We also discuss how recent technological advances will help identify additional factors involved in the differential hormonal regulation of LH and FSH.

With our increasing appreciation that simply maximizing oocyte yield for all patients is no longer an appropriate stimulation strategy and that age alone cannot accurately predict ovarian response, there has been an explosion in the literature regarding the utility of biomarkers to predict and individualize treatment strategies. Antral follicle count (AFC) and antimüllerian hormone (AMH) have begun to dominate the clinical scene, and although frequently pitted against each other as alternatives, both may contribute and indeed be synergistic. Their underlying technologies are continuing to develop rapidly and overcome the standardization issues that have limited their development to date. In the context of in vitro fertilization (IVF), their linear relationship with oocyte yield and thereby extremes of ovarian response has led to improved pretreatment patient counseling, individualization of stimulation strategies, increased cost effectiveness, and enhanced safety. This review highlights that although biomarkers of ovarian response started in the IVF clinic, their future extends well beyond the boundaries of assisted reproduction. The automation of AMH and its introduction into the routine repertoire of clinical biochemistry has tremendous potential. A future where primary care physicians, endocrinologists, and oncologists can rapidly assess ovarian dysfunction and the ovarian reserve more accurately than with the current standard of follicle-stimulating hormone (FSH) is an exciting possibility. For women, the ability to know the duration of their own reproductive life span will be empowering and allow them to redefine the meaning of family planning.

In addition to pituitary gonadotropins and paracrine factors, ovarian follicle development is also modulated by oocyte factors capable of stimulating granulosa cell proliferation but suppressing their differentiation. The nature of these oocyte factors is unclear. Because growth differentiation factor-9 (GDF-9) enhanced preantral follicle growth and was detected in the oocytes of early antral and preovulatory follicles, we hypothesized that this oocyte hormone could regulate the proliferation and differentiation of granulosa cells from these advanced follicles. Treatment with recombinant GDF-9, but not FSH, stimulated thymidine incorporation into cultured granulosa cells from both early antral and preovulatory follicles, accompanied by increases in granulosa cell number. Although GDF-9 treatment alone stimulated basal steroidogenesis in granulosa cells, cotreatment with GDF-9 suppressed FSH-stimulated progesterone and estradiol production. In addition, GDF-9 cotreatment attentuated FSH-induced LH receptor formation. The inhibitory effects of GDF-9 on FSH-induced granulosa cell differentiation were accompanied by decreases in the FSH-induced cAMP production. These data suggested that GDF-9 is a proliferation factor for granulosa cells from early antral and preovulatory follicles but suppresses FSH-induced differentiation of the same cells. Thus, oocyte-derived GDF-9 could account, at least partially, for the oocyte factor(s) previously reported to control cumulus and granulosa cell differentiation.

Signaling between kisspeptin and its receptor, G-protein-coupled receptor 54 (Gpr54), is now recognized as being essential for normal fertility. However, the key cellular location of kisspeptin-Gpr54 signaling is unknown. Here we create a mouse with a GnRH neuron-specific deletion of Gpr54 to assess the role of gonadotropin-releasing hormone (GnRH) neurons. Mutant mice are infertile, fail to go through puberty and exhibit markedly reduced gonadal size and follicle-stimulating hormone levels alongside GnRH neurons that are unresponsive to kisspeptin. In an attempt to rescue the infertile phenotype of global Gpr54⁻/⁻ mutants, we use BAC transgenesis to target Gpr54 to the GnRH neurons. This results in mice with normal puberty onset, estrous cyclicity, fecundity and a recovery of kisspeptin's stimulatory action upon GnRH neurons. Using complimentary cell-specific knockout and knockin approaches we demonstrate here that the GnRH neuron is the key site of kisspeptin-Gpr54 signaling for fertility.

OBJECTIVE

To investigate whether leptin is linked to reproduction, circulating levels were measured longitudinally throughout spontaneous menstrual cycles and during pregnancy in normal women.

METHODS

Longitudinal blood samples were collected from normal volunteers, either during regular menstrual cycles or during successful singleton pregnancies.

METHODS

Six healthy, regularly cycling, women volunteers (31.5 +/- 3.0 years old, BMI = 21.6 +/- 0.5) were recruited for serial venous blood sampling throughout one complete menstrual cycle. In addition, five healthy, women (31.8 +/- 1.2 years old, pregnant BMI = 30.0 +/- 3.1) provided serial venous blood samples throughout one complete singleton pregnancy.

METHODS

Circulating venous oestradiol, progesterone, luteinizing hormone (LH), follicle-stimulating hormone (FSH), leptin and (pregnant group only) human chorionic gonadotrophin (hCG).

RESULTS

In spontaneously cycling women, changes in circulating leptin levels were associated with menstrual phase (P < 0.001) and correlated with progesterone levels (P < 0.05). Peak leptin concentrations were recorded during the luteal phase (P < 0.01), coincident with maximal progesterone levels (P < 0.05). Leptin concentrations were elevated throughout gestation (P < 0.05), and especially during the second trimester (P < 0.05). Post-partum, circulating leptin levels fell sharply to below pregnant values. Leptin correlated with oestradiol (P < 0.05) and human chorionic gonadotrophin (hCG, P < 0.01) levels during pregnancy. First trimester (P < 0.05) and postpartum (P < 0.05) oestradiol concentrations and post-partum hCG levels exhibited the greatest correlation with circulating leptin.

CONCLUSIONS

We conclude that the relationship between body mass index and circulating leptin varies during the course of spontaneous cycles in women, the best correlation occurring during the luteal phase when progesterone and leptin concentrations are highest. This, together with the correlation between circulating oestradiol, hCG and leptin levels during pregnancy, strongly suggests a dynamic relationship between leptin and reproductive events in women.

We have reported that members of the bcl-2 gene family are expressed and gonadotropin regulated in ovarian granulosa cells during follicular maturation and atresia. Because Bcl-2, a protein that prevents apoptosis in several cell types, is reported to function as an antioxidant or free radical scavenger, the present studies were designed to investigate if oxidative stress plays a role in granulosa cell apoptosis during follicular atresia in the immature rat ovary. In the first series of experiments, the role of oxidative stress in the induction of granulosa cell apoptosis was directly tested using a defined in vitro follicle culture system. Healthy antral follicles obtained from equine CG (eCG)-primed immature (27 day old) rats were incubated in serum-free medium for 24 h in the absence or presence of FSH (100 ng/ml; a control for inhibiting apoptosis), superoxide dismutase (SOD; 10-1000 U/ml), ascorbic acid (0.01-1 mM; a free radical scavenger), N-acetyl-L-cysteine (25-100 mM; a free radical scavenger and stimulator of endogenous glutathione peroxidase activity), or catalase (10-1000 U/ml). Granulosa cells within follicles incubated in medium alone exhibited extensive apoptosis after 24 h of incubation, and this onset of apoptosis was blocked by treatment with FSH (29 +/- 4% of controls; P < 0.001, n = 3). Moreover, apoptosis in follicles was also inhibited by treatment with SOD (44 +/- 4% of controls at 1000 U/ml; P < 0.01, n = 3), ascorbic acid (55 +/- 9% of controls at 1 mM; P < 0.05, n = 3), N-acetyl-L-cysteine (24 +/- 7% of controls at 100 mM; P < 0.001, n = 3), or catalase (35 +/- 6% of controls at 1000 U/ml; P < 0.001, n = 3). In the second series of experiments, complementary DNAs corresponding to secreted (SEC-SOD), copper/zinc-containing (Cu/Zn-SOD), and manganese-containing (Mn-SOD) forms of rat SOD, rat seleno-cysteine glutathione peroxidase (GSHPx), and rat catalase were isolated and used to synthesize antisense RNA probes for Northern and slot blot analysis of changes in SOD, GSHPx, and catalase gene expression during follicular maturation. In vivo priming of 25-day-old female rats for 2 days with 10 IU eCG, which promoted antral follicular growth and survival, increased levels of messenger RNA encoding SEC-SOD (216 +/- 9% of saline-treated controls, P < 0.05, n = 3) and Mn-SOD (222 +/- 14% of saline-treated controls, P < 0.05, n = 3) vs. saline-treated controls.(ABSTRACT TRUNCATED AT 400 WORDS)

Neuromuscular and hormonal adaptations to prolonged strength training were investigated in nine elite weight lifters. The average increases occurred over the 2-yr follow-up period in the maximal neural activation (integrated electromyogram, IEMG; 4.2%, P = NS), maximal isometric leg-extension force (4.9%, P = NS), averaged concentric power index (4.1%, P = NS), total weight-lifting result (2.8%, P less than 0.05), and total mean fiber area (5.9%, P = NS) of the vastus lateralis muscle, respectively. The training period resulted in increases in the concentrations of serum testosterone from 19.8 +/- 5.3 to 25.1 +/- 5.2 nmol/l (P less than 0.05), luteinizing hormone (LH) from 8.6 +/- 0.8 to 9.1 +/- 0.8 U/l (P less than 0.05), follicle-stimulating hormone (FSH) from 4.2 +/- 2.0 to 5.3 +/- 2.3 U/l (P less than 0.01), and testosterone-to-serum sex hormone-binding globulin (SHBG) ratio (P less than 0.05). The annual mean value of the second follow-up year for the serum testosterone-to-SHBG ratio correlated significantly (r = 0.84, P less than 0.01) with the individual changes during the 2nd yr in the averaged concentric power. The present results suggest that prolonged intensive strength training in elite athletes may influence the pituitary and possibly hypothalamic levels, leading to increased serum levels of testosterone. This may create more optimal conditions to utilize more intensive training leading to increased strength development.

Although it has been shown that granulosa cells regulate the growth and meiotic maturation of mammalian oocytes, there is little evidence of a role for the oocyte in the differentiation or function of granulosa cells. To test the hypothesis that the oocyte participates in the regulation of granulosa cell function, oocytes were removed from isolated oocyte-cumulus cell complexes by a microsurgical procedure and oocytectomized complexes were tested for their ability to undergo expansion in response to follicle-stimulating hormone (FSH). FSH increased the levels of intracellular cAMP, the activity of the hyaluronic acid-synthesizing enzyme system, and induced cumulus expansion in intact complexes. In contrast, FSH did not induce increased hyaluronic acid-synthesizing enzyme activity or cumulus expansion in oocytectomized complexes. Therefore, the participation of the oocyte is necessary for the cumulus cells to synthesize hyaluronic acid and undergo cumulus expansion in vitro in response to stimulation with FSH. FSH induced the elevation of intracellular cAMP to the same extent in both intact and oocytectomized complexes and the cAMP analog 8-bromo cyclic adenosine monophosphate (8Br-cAMP) did not stimulate expansion in oocytectomized complexes. Therefore, the influence of the oocyte on cumulus expansion occurs downstream from the elevation of cAMP levels in the cumulus cells. Epidermal growth factor (EGF), a potent stimulator of cumulus expansion in intact complexes, which probably acts by a mechanism at least initially different from FSH, failed to stimulate cumulus expansion after oocytectomy. Next, oocytectomized complexes were either cocultured with germinal vesicle stage denuded oocytes or cultured in medium conditioned by denuded oocytes. In both cases, FSH or EGF stimulated expansion by oocytectomized complexes. The degree of expansion was directly correlated to the number of oocytes used to condition the medium. Contact between the oocyte and the cumulus cells is not necessary for cumulus expansion. Rather, a factor(s) secreted by the oocyte is necessary for the cumulus cells to undergo expansion in response to either FSH or EGF. FSH did not induce expansion of oocytectomized complexes in media conditioned by various somatic cells such as granulosa cells, fibroblasts, and Sertoli cells; by a mixed population of male germ cells; or by spermatozoa. This suggests that the expansion enabling activity is specific to the oocyte. These results demonstrate that the oocyte participates in the regulation of cumulus cell function.

We report a woman with primary amenorrhoea and infertility associated with an isolated deficiency of pituitary follicle-stimulating hormone (FSH), but normal luteinizing hormone (LH) secretion. Ovulation was induced by administration of exogenous FSH and resulted in a successful pregnancy. Sequence analysis of the FSH beta-subunit gene indicated that she is homozygous for a two nucleotide frameshift deletion in the coding sequence. Her mother and son are heterozygous for this mutation. This deletion results in an alteration of amino acid codons 61-86 followed by a premature termination codon. The predicted truncated beta-subunit peptide lacks regions which are important for association with the alpha subunit and for binding to and activation of the FSH receptor. Abnormalities of FSH structure or function might be an under recognised but treatable cause of infertility.

Sex hormone-binding globulin (SHBG) transports androgens and estrogens in blood and regulates their access to target tissues. Hepatic production of SHBG fluctuates throughout the life cycle and is influenced primarily by metabolic and hormonal factors. Genetic differences also contribute to interindividual variations in plasma SHBG levels. In addition to controlling the plasma distribution, metabolic clearance, and bioavailability of sex steroids, SHBG accumulates in the extravascular compartments of some tissues and in the cytoplasm of specific epithelial cells, where it exerts novel effects on androgen and estrogen action. In mammals, the gene-encoding SHBG is expressed primarily in the liver but also at low levels in other tissues, including the testis. In subprimate species, Shbg expression in Sertoli cells is under the control of follicle-stimulating hormone and produces the androgen-binding protein that influences androgen actions in the seminiferous tubules and epididymis. In humans, the SHBG gene is not expressed in Sertoli cells, but its expression in germ cells produces an SHBG isoform that accumulates in the acrosome. In fish, Shbg is produced by the liver but has a unique function in the gill as a portal for natural steroids and xenobiotics, including synthetic steroids. However, salmon have retained a second, poorly conserved Shbg gene that is expressed only in ovary, muscle, and gill and that likely exerts specialized functions in these tissues. The present review compares the production and functions of SHBG in different species and its diverse effects on reproduction.

One of the molecular mechanisms shown to have played a major role in orchestrating the expression of the many genes with unique cellular and temporal specificity in spermatogenesis, is the cAMP-dependent signaling pathway. In this pathway, gene expression is mediated primarily by two members of the bZIP transcription factors-cAMP-response element binding protein (CREB) and cAMP-responsive element modulator (CREM). Both bind a specific cis element, cAMP-response element (CRE), in the promoter of target genes, both are activated by protein kinase A (PKA) phosphorylation that enables binding of CREB binding protein (CBP) and recruitment of the basal transcription machinery, and both are characterized by multiple alternatively spliced forms. Some of these alternatively spliced forms lack the transactivation domains and hence function as transcription suppressors. In Sertoli cells, CREB levels fluctuate in a cyclical manner that depends on the specific cell associations along the spermatogenic wave. Follicle stimulating hormone (FSH) activates the cAMP signaling pathway and consequently, CREB positively auto-regulates its own expression (by binding to a CRE like element in its promoter). Subsequently, activated CREB activates transcription of genes essential for proper germ cell differentiation. In addition, TNFalpha secreted by round spermatids, activates NF-kappaB dependent CREB expression in Sertoli cells and thus, contributes to the elevated CREB levels as long as these cells are intimately associated. Inducible cAMP early repressor (ICER), a suppressor isoform of CREM, also activated by CREB, down regulates CREB expression together with its own expression, resetting CREB to basal level that enables a new spermatogenic wave. In germ cells, antagonist forms of CREM (alpha, beta and gamma) are present in premeiotic cells and early prophase spermatocytes. A prominent switch to the CREMtau and CREMtheta; activating forms starts in pachytene spermatocytes leading to the activation of haploid genes important for spermiogenesis in round spermatids. Interestingly, in germ cells, CREM exerts activation of haploid genes independent of its phosphorylation state. It associates with activator of CREM in testis (ACT), that has an intrinsic transcriptional activity, rather than with CBP. These and other findings suggest that the expanding CREB/CREM proteins and potentially other members of the CREB family are key molecular regulators at all stages of spermatogenesis.

OBJECTIVE

The objective of this study was to evaluate the relationship between anti-mullerian hormone (AMH), inhibin B and antral follicle count (AFC) with ovarian response.

METHODS

Retrospective study.

METHODS

Fertility unit.

METHODS

AFC was recorded, and a serum sample obtained on day 3 from all patients undergoing in vitro fertilisation (IVF). Patients were given 300 IU/L recombinant follicle stimulating hormone (FSH; Gonal F). The following day blood samples were collected. METHODS Serum samples were assayed for FSH, AMH and inhibin B using commercial immunoassay kits and oestradiol using an in house assay.

METHODS

Response to gonadotrophin stimulation and the number of eggs collected.

RESULTS

AFC was negatively correlated to age (r=-0.426, P < 0.001). Delta inhibin B (levels of inhibin B on day 4 minus day 3) had the best association to the number of eggs collected (r= 0.533, P < 0.001) followed by basal AMH (r= 0.51, P < 0.001) and AFC (r= 0.505, P < 0.001). The number of eggs fertilised was significantly associated with basal AMH (r= 0.592, P < 0.001) and inhibin B (r= 0.548, P < 0.001). AMH with a cutoff of 0.2 ng/mL had the best sensitivity (87%) and specificity (64%) in predicting poor response. A cumulative score using basal FSH, basal AMH, delta E2 (levels of oestradiol on day 4 minus day 3), delta inhibin B, AFC and age gives the best predictive statistics to identify poor responders with 87% sensitivity and 80% specificity and a positive likelihood ratio of 4.36.

CONCLUSIONS

Delta inhibin B had the best positive association with the number of eggs collected and basal AMH is the single best predictor of poor response. AFC has a significant association with the number of eggs collected and is predictive of clinical pregnancy. It is evident that a single parameter is of limited value in predicting ovarian response. However, we have demonstrated a cumulative score using all the above markers could be useful in predicting poor response.

Few studies have prospectively examined lipid changes across the menopause transition or in relation to menopausal changes in endogenous hormones. The relative independent contributions of menopause and age to lipid changes are unclear. Lipid changes were examined in relation to changes in menopausal status and in levels of estradiol and follicle-stimulating hormone in 2,659 women followed in the Study of Women's Health Across the Nation (1995-2004). Baseline age was 42-52 years, and all were initially pre- or perimenopausal. Women were followed annually for up to 7 years (average, 3.9 years). Lipid changes occurred primarily during the later phases of menopause, with menopause-related changes similar in magnitude to changes attributable to aging. Total cholesterol, low density lipoprotein cholesterol, triglycerides, and lipoprotein(a) peaked during late peri- and early postmenopause, while changes in the early stages of menopause were minimal. The relative odds of low density lipoprotein cholesterol >> or =130 mg/dL) for early postmenopausal, compared with premenopausal, women were 2.1 (95% confidence interval: 1.5, 2.9). High density lipoprotein cholesterol also peaked in late peri- and early postmenopause. Results for estradiol and follicle-stimulating hormone confirmed the results based on status defined by bleeding patterns. Increases in lipids were smallest in women who were heaviest at baseline.

BACKGROUND

Studies of fertility in men treated for testicular cancer have mainly addressed serum follicle-stimulating hormone levels and sperm parameters. We assessed post-treatment paternity among long-term survivors of testicular cancer.

METHODS

Men (n = 1814) who had been treated for unilateral testicular cancer in Norway during 1980 through 1994 were invited to participate in a national multi-center follow-up survey in 1998 through 2002. The participants were allocated to five groups according to the treatment received after orchiectomy, including treatment at relapse (surveillance, retroperitoneal lymph node dissection, radiotherapy, low-dose chemotherapy [i.e., < or = 850 mg cisplatin], and high-dose chemotherapy [i.e.,>> 850 mg cisplatin]). Cox proportional hazards analysis was used to assess predictive factors for post-treatment paternity. Statistical tests were two-sided.

RESULTS

A total of 1433 men were assessable, of whom 827 were fathers at diagnosis. Post-treatment conception was attempted by 554 men, among whom the overall 15-year actuarial post-treatment paternity rate was 71% (95% confidence interval [CI] = 66% to 75%) without the use of cryopreserved semen. This rate ranged from 48% (95% CI = 30% to 69%) in the high-dose chemotherapy group to 92% (95% CI = 78% to 98%) in the surveillance group (P < .001). The median actuarial time from diagnosis to the birth of the first child after treatment was 6.6 years overall but varied according to treatment. Assisted reproductive technologies were used by 22% of the couples who attempted conception after treatment. Dry ejaculation, treatment group, pretreatment fatherhood, and marital status were statistically significant independent predictors for post-treatment fatherhood, with dry ejaculation as the most important negative factor.

CONCLUSIONS

Although the overall paternity rate after treatment for testicular cancer was high, the ability to conceive and the time to conception reflected the intensity of treatment. These data may help inform patients about their future ability to father biological children.

An early first pregnancy is known to protect against subsequent breast cancer. We speculated that this effect may be mediated by a long-term depression of prolactin secretion after pregnancy. We therefore measured basal and post-stimulation serum levels of prolactin, luteinizing hormone (LH), and follicle-stimulating hormone (FSH) in two groups--15 women 18 to 23 years of age and 9 women 29 to 40--before and after a first full-term pregnancy, and in 40 appropriate nulliparous controls. We observed no significant change in basal levels of serum LH or FSH or in the levels stimulated by gonadotropin-releasing hormone in any group. A significant decrease was seen, however, in basal and perphenazine-stimulated levels of prolactin after pregnancy in both the younger and older first-pregnancy groups but not in the controls. In a separate cross-sectional study, we compared basal serum prolactin levels in 29 parous and 19 nulliparous women of similar age. The serum prolactin levels were significantly lower in the parous group but were not related to the number of pregnancies (one to three) or the time elapsed (12 to 150 months) since the last delivery. We conclude that a first pregnancy leads to a long-term decrease in serum prolactin secretion, lasting at least 12 to 13 years.

Inhibin B levels were measured in serum from 400 healthy Danish prepubertal, pubertal, and adolescent males, aged 6-20 yr, in a cross-sectional study using a recently developed immunoassay that is specific for inhibin B, the physiologically important inhibin form in men. In addition, serum levels of FSH, LH, testosterone, and estradiol levels were measured. Serum levels of inhibin B, FSH, LH, testosterone, and estradiol all increased significantly between stages I and II of puberty. From stage II of puberty the inhibin B level was relatively constant, whereas the FSH level continued to increase between stages II and III. From stage III of puberty the FSH level was also relatively constant, although there was a nonsignificant trend of slightly decreased FSH levels at pubertal stage V compared to stage IV. The levels of serum LH, testosterone, and estradiol increased progressively throughout puberty. In prepubertal boys younger than 9 yr, there were no correlation between inhibin B and the other three hormones. In prepubertal boys older than 9 yr, a significant positive correlation was observed between inhibin B and FSH, LH, and testosterone. However, at this pubertal stage, each hormone correlated strongly with age, and when the effect of age was taken into account, only the partial correlation between inhibin B and LH/testosterone remained statistically significant. At stage II of puberty, the positive partial correlation between inhibin B and LH/testosterone was still present. At stage III of puberty, an negative partial correlation between inhibin B and FSH, LH, and estradiol was present, whereas no correlation between inhibin B and testosterone could be observed from stage III onward. The negative correlation between inhibin B and FSH persisted from stage III of puberty onward, whereas the correlation between inhibin B and LH and between inhibin B and estradiol was nonsignificant at stages IV and V of puberty. In conclusion, in boys, serum inhibin B levels increase early in puberty; by pubertal stage II the adult level of inhibin B has been reached. The correlation of inhibin B to FSH, LH, and testosterone changes during pubertal development. Early puberty is characterized by a positive correlation between inhibin B and LH/testosterone, but no correlation to FSH. Late puberty (from stage III) is characterized by a negative correlation between inhibin B and FSH (which is maintained in adult men), a diminishing negative correlation between inhibin B and LH, and no correlation between inhibin B and testosterone, suggesting that developmental and maturational processes in the hypothalamic-pituitary-gonadal axis take place, leading to the establishment of the closed loop feedback regulation system operating in adult men. The positive correlation between inhibin B and LH/ testosterone at the time when serum inhibin B levels rise early in puberty suggests that Leydig cell factors may play an important role in the maturation and stimulation of Sertoli cells in the beginning of pubertal development.

The expansion, or mucification, of the mouse cumulus oophorus in vitro requires the presence of an enabling factor secreted by the oocyte as well as stimulation with follicle-stimulating hormone (FSH). This study focuses on (1) the ability of mouse oocytes to secrete the enabling factor at various times during oocyte growth and maturation, (2) the temporal relationships between the development of the capacity of the oocyte to undergo germinal vesicle breakdown, the ability of the oocyte to secrete cumulus expansion-enabling factor, and the capacity of the cumulus oophorus to undergo expansion, and (3) the role of the oocyte in the differentiation of granulosa cells as functional cumulus cells. Growing, meiotically incompetent oocytes did not produce detectable amounts of cumulus expansion-enabling factor, but fully grown meiosis-arrested oocytes, maturing oocytes, and metaphase II oocytes did. Detectable quantities of enabling factor were produced by zygotes, but not by two-cell stage to morula embryos. The ability of oocytes to secrete cumulus expansion enabling factor and the capacity of cumulus cells to respond to FSH and the enabling factor are temporally correlated with the acquisition of oocyte competence to undergo germinal vesicle breakdown. Mural granulosa cells of antral follicles do not expand in response to FSH even in the presence of cumulus expansion-enabling factor, showing that mural granulosa cells and cumulus cells are functionally distinct cell types. The perioocytic granulosa cells of preantral follicles isolated from 12-day-old mice differentiate into functional cumulus cells during a 7-day period in culture. Oocytectomized granulosa cell complexes grown in medium conditioned by either growing or fully grown oocytes were comparable in size to intact complexes and maintained their 3-dimensional integrity to a greater degree than oocytectomized complexes grown in unconditioned medium. After 7 days, the oocytectomized complexes were stimulated with FSH in the presence of enabling factor, but no expansion was observed whether or not the oocytectomized complexes grew in the presence of oocyte-conditioned medium. These results suggest that a factor(s) secreted by the oocyte affects granulosa cell proliferation and the structural organization of the follicle, but continual close association with the oocyte appears necessary for the differentiation of granulosa cells into functional cumulus cells, insofar as they are capable of undergoing expansion.

Proper functioning of the mammalian testis is dependent upon an array of hormonal messengers acting through endocrine, paracrine, and autocrine pathways. Within the testis, the primary messengers are the gonadotrophins, follicle stimulating hormone and luteinizing hormone, and the androgens. Abundant evidence indicates that the role of the gonadotrophins is to maintain proper functioning of testicular somatic cells. It is the androgens, primarily testosterone, which act through the somatic cells to regulate germ cell differentiation. Despite extensive research in this area, little is known about the cell-specific requirements for androgens and even less is understood about the downstream effectors of androgen signalling. However, recent work using cell-specific ablation of androgen receptor function has demonstrated a clear requirement for androgen signalling at multiple, discrete time points during spermatogenesis. These models also provide useful tools for identifying the targets of androgen receptor activity. The purpose of this review is to provide a brief overview of recent advances in our understanding of hormonal regulation of spermatogenesis, with an emphasis on the role of testosterone within the testis, and to pose important questions for future research in this field.

Recent studies have focused on reproductive health of men in the general population. However, semen samples are difficult to obtain within sampling frames that allow comparisons. Blood samples are easier to obtain than ejaculates. Therefore, serum biomarkers of spermatogenesis are of major interest for population studies. FSH has previously been used as a marker of spermatogenesis, although it is also influenced by the hypothalamus. Serum inhibin B was recently suggested as a possible, more direct serum marker of spermatogenesis in men with testicular disorders. In a Danish nationwide collaborative study, we found an unexpected difference in semen concentration between two groups of men recruited from two different centres. We, therefore, analyzed reproductive hormones in blood, including inhibin B, to test whether the observed difference in semen concentration was reflected in the reproductive hormones. From 1992 to 1995, a total of 430 men, 20-35 yr old, who lived with a partner and who had not previously attempted to achieve a pregnancy, were recruited. The couples were enrolled into the study in one of two centres (centre A, n = 231; and centre B, n = 199) when they discontinued birth control. At enrollment, they provided a semen sample (n = 419), and a blood sample was drawn (n = 349). The semen analysis was performed in accordance with the WHO 1992 guidelines, and interlaboratory differences were tested. Inhibin B was measured in an enzyme immunometric assay, which has previously been described. All blood samples were analyzed in the same laboratory. Median sperm concentration and the percentage of morphologically normal spermatozoa were significantly higher among men from centre A (56.0 mill/mL and 42.5%), compared with men from centre B (44.8 mill/mL and 39%). Men from centre B had a significantly higher median FSH (3.42 IU/L) and a lower inhibin B (186 pg/mL) than men from centre A (3.21 IU/L and 209 pg/mL). The differences persisted after control for potentially confounding variables. A significant correlation was found between the cubic root-transformed serum FSH and inhibin B levels (r = -0.61, P < 0.001), between the cubic root-transformed serum FSH and sperm concentration (r = -0.40, P < 0.001), and between the cubic root-transformed inhibin B and sperm concentration (r = 0.38, P < 0.001). The predictive power of detecting sperm counts below 20 mill/mL among men who's inhibin B and FSH both were below 80 pg/mL and above 10 IU/L, respectively, was 100%. The unexpected significant difference in semen concentration between two groups of normal Danish men was probably caused by differences in sampling procedures in the two centres where the men were recruited, rather than geographical differences. However, similar differences in serum levels of inhibin B and FSH between centres were found. These findings suggest that a real difference in spermatogenic potential between the two groups of men existed. We suggest that serum inhibin B, in future population studies on male reproductive health, may serve as a new marker of spermatogenesis, in addition to sperm concentration and serum FSH.

The effects of estradiol, FSH and LH on ovarian follicular development and granulosa cell differentiation were examined in the immature rat hypophysectomized on day 24 of age. Administration of estradiol to hypophysectomized rats for 4 days stimulated the growth of large preantral follicles with a concomitant 1.5-fold increase in FSH receptor content and a 4-fold decrease in LH receptor content in the granulosa cells. When highly purified hFSH was administered alone, receptor content for FSH increased progressively for 4 days while receptor for LH remained essentially unchanged. However, when rats were pretreated with estradiol, the response of follicles to FSH was markedly enhanced as indicated by the appearance of large, antral follicles and elevated receptor content for both FSH and LH. Receptor content for FSH increased markedly in response to hFSH following only one day of estradiol pretreatment, while receptor content for LH increased most rapidly in response to hFSH after 3 days of estradiol pretreatment. LH administered to rats possessing large preovulatory follicles caused luteinization of granulosa cells and a marked decline in receptor content for both gonadotropins within 24 h. Receptor content remained low even 48 h after LH administration when granulosa cells were fully luteinized. These results indicated that follicular development and granulosa cell differentiation are dependent on steroid-protein hormone regulation of hormone specific receptors.