OR11-05 Clinical Characteristics and Reproductive Hormone Levels in 201 Men With Congenital and 479 Men With Acquired Hypogonadotropic Hypogonadism: A Single-Center Comparative Study

Abstract Context. Hypogonadotropic hypogonadism (HH) is a clinical condition defined by subnormal serum testosterone levels with low serum gonadotropins, which leads to infertility and reduced testicular function in men. HH may be prenatal or congenital (CHH) or acquired (AHH), the latter most commonly related to injury at the hypothalamic/pituitary level. Since diverse medical specialists usually deal with these two disorders, a direct comparison of clinical characteristics and reproductive hormone levels in patients with CHH and AHH has never been performed in a large series. Patients and methods. 201 men with CHH (Kallmann syndrome 52%; normosmic CHH 48%) and 479 men with AHH were included. Causes for AHH included pituitary tumors (74.6%), other intracranial tumors (12.7%; craniopharyngioma 9.1%), infiltrative diseases (3.5%), and other causes (9.2%). We excluded patients with idiopathic late-onset or metabolically-related AHH from this analysis. Testicular volume (TV), serum gonadotropins, total and bioavailable testosterone (TT and BT), estradiol (E2) and testicular peptides inhibin B (IB), AMH and INSL3 were measured at a single center in the absence of any hormone replacement. Results. TV was greater in patients with AHH (16.2±6.3 mL) than in those with CHH (3.4±2.7 mL; p<0.0001). Testicular hypotrophy (mean TV<12 mL) was found in 30% of patients with AHH and in 97% of those with CHH (p<0.0001). When adjusted for age and BMI, men with AHH still had a larger mean TV than those with CHH (p<0.0001). Cryptorchidism was more frequent in patients with CHH than in those with AHH (20.4 vs 0.2%, p<0.0001). Micropenis was found exclusively in patients with CHH. TT levels were higher in patients with AHH (1.4±0.9 ng/mL) than in those with CHH (0.4±0.3 mL, p<0.0001). LH, FSH, BT and E2 were higher in patients with AHH than in those with CHH (p<0.0001 for all parameters), as were IB and INSL3 levels (126±87 vs 59±55 pg/mL, and 566±372 vs 60±40 pg/mL, respectively, p<0.001). In contrast, serum AMH and SHBG levels were lower in patients with AHH than in those with CHH (246±234 vs 46±38 pmol/L, and 35±22 vs 26±21 nmol/L, respectively, p<0.0001). Comparing hormone characteristics across different AHH subgroups, patients with craniopharyngioma (n=44) had lower TV (7.7±5.3 mL) and lower TT, BT, E2, IB and INSL3 levels than those with AHH caused by any other etiology (p<0.05 for all parameters). Conclusions. Our data demonstrate distinct profiles of clinical presentation and reproductive hormones between CHH and AHH. Clinical and hormonal impairment is more severe in patients with CHH than in those with AHH. Preservation of the gonadotrope/testicular axis activity during the fetal, neonatal and pubertal periods in patients with AHH likely accounts for these differences. Among AHH etiologies, patients with craniopharyngioma have the most severe impairment, likely as a result of the intrinsic severity of these tumors, the age at onset, and/or the aggressiveness of the available therapeutic procedures.

Download Full-text

Age-related changes in the oestrous cycle and reproductive hormones in senescence-accelerated mouse

Reproduction Fertility and Development ◽

10.1071/rd04099 ◽

2005 ◽

Vol 17 (5) ◽

pp. 507 ◽

Cited By ~ 10

Author(s):

Ma Yuan ◽

Zhou Wen-Xia ◽

Cheng Jun-Ping ◽

Zhang Yong-Xiang

Keyword(s):

Substance P ◽

Luteinising Hormone ◽

Reproductive Hormones ◽

Oestrous Cycle ◽

Reproductive Hormone ◽

Hormone Levels ◽

Age Related ◽

Samp8 Mice ◽

Senescence Accelerated Mouse ◽

Age Related Changes

To investigate age-related changes in the oestrous cycle and reproductive hormone levels in senescence-accelerated mouse (SAM), we examined these parameters in 3-, 5-, 7-, 9- and 11-month-old female SAM-prone/8 (SAMP8) and SAM-resistant/1 (SAMR1) strains. Levels of β-endorphin (β-EP) and substance P (SP) in the hypothalamus were also measured. The oestrous cycle and dioestrus of 9-month-old SAMP8 mice were significantly prolonged compared with age-matched SAMR1 mice. Furthermore, the concentration of serum oestradiol was lower and the level of pituitary luteinising hormone was higher in SAMP8 mice compared with SAMR1 mice. This characterises the hypothalamus–pituitary–ovary (HPO) axis of the SAMP8 strain as hypergonadotropic–hypogonad. The levels of β-EP and SP in the SAMP8 hypothalamus were lower than in the SAMR1 hypothalamus. These results indicate that the function of the HPO axis in SAMP8 mice declines early and this may be attributed, in part, to the decline in β-EP and SP concentrations in the hypothalamus.

Download Full-text

Erratum to: Age-related changes in the oestrous cycle and reproductive hormones in senescence-accelerated mouse

Reproduction Fertility and Development ◽

10.1071/rd04099_er ◽

2009 ◽

Vol 21 (4) ◽

pp. 624

Author(s):

Ma Yuan ◽

Zhou Wen-Xia ◽

Cheng Jun-Ping ◽

Zhang Yong-Xiang

Keyword(s):

Substance P ◽

Luteinising Hormone ◽

Reproductive Hormones ◽

Oestrous Cycle ◽

Reproductive Hormone ◽

Hormone Levels ◽

Age Related ◽

Samp8 Mice ◽

Senescence Accelerated Mouse ◽

Age Related Changes

To investigate age-related changes in the oestrous cycle and reproductive hormone levels in senescence-accelerated mouse (SAM), we examined these parameters in 3-, 5-, 7-, 9- and 11-month-old female SAM-prone/8 (SAMP8) and SAM-resistant/1 (SAMR1) strains. Levels of �-endorphin (�-EP) and substance P (SP) in the hypothalamus were also measured. The oestrous cycle and dioestrus of 9-month-old SAMP8 mice were significantly prolonged compared with age-matched SAMR1 mice. Furthermore, the concentration of serum oestradiol was lower and the level of pituitary luteinising hormone was higher in SAMP8 mice compared with SAMR1 mice. This characterises the hypothalamus.pituitary.ovary (HPO) axis of the SAMP8 strain as hypergonadotropic.hypogonad. The levels of �-EP and SP in the SAMP8 hypothalamus were lower than in the SAMR1 hypothalamus. These results indicate that the function of the HPO axis in SAMP8 mice declines early and this may be attributed, in part, to the decline in �-EP and SP concentrations in the hypothalamus.

Download Full-text

Effects of Female Reproductive Hormone Levels on Inadvertent Intraoperative Hypothermia during Laparoscopic Gynecologic Surgery: A Retrospective Study

Medicina ◽

10.3390/medicina57111255 ◽

2021 ◽

Vol 57 (11) ◽

pp. 1255

Author(s):

Cheol Lee ◽

SeongNam Park ◽

ByoungRyun Kim ◽

Hyeonbin Yim ◽

Myeongjong Lee ◽

...

Keyword(s):

Retrospective Study ◽

General Anesthesia ◽

Odds Ratio ◽

Reproductive Hormones ◽

Gynecologic Surgery ◽

Reproductive Hormone ◽

Hormone Levels ◽

Intraoperative Hypothermia ◽

Hypothermia Group ◽

Laparoscopic Gynecologic Surgery

Background and Objectives: Female reproductive hormones may affect core body temperature. This study aimed to investigate the effects of female reproductive hormones on inadvertent intraoperative hypothermia in patients who underwent laparoscopic gynecologic surgery under general anesthesia. Materials and Methods: This retrospective study included 660 menstruating and menopausal female patients aged 19–65 years. The patients were divided into two groups according to the occurrence of inadvertent intraoperative hypothermia: non-hypothermia group (N = 472) and hypothermia group (N = 188). After propensity score matching, 312 patients (N = 156 in each group) were analyzed to investigate the association between intraoperative hypothermia and female reproductive hormones. As potential predictors of inadvertent hypothermia, the levels of female reproductive hormones were analyzed using binary logistic regression. Results: The association of estradiol (r = −0.218, p = 0.000) and progesterone (r = −0.235, p = 0.000) levels with inadvertent intraoperative hypothermia was significant but weakly negative before matching; however, it was significant and moderately negative after matching (r = −0.326, p = 0.000 and r = −0.485, p = 0.000, respectively). In a binary logistic analysis, the odds ratio for estradiol was 0.995 (p = 0.014, 0.993 < 95% confidence interval [CI] < 0.998) before matching and 0.993 (p = 0.000, 0.862 < 95% CI < 0.930) after matching, and that for progesterone was 0.895 (p = 0.000, 0.862 < 95% CI < 0.930) before matching and 0.833 (p = 0.014, 0.990 < 95% CI < 0.996) after matching. Conclusions: Estradiol and progesterone levels were associated with inadvertent intraoperative hypothermia. However, the odds ratio for female reproductive hormone levels was close to 1. Therefore, female reproductive hormones may not be a risk factor for hypothermia during gynecologic surgery under general anesthesia. However, a small sample size in this study limits the generalizability of the results.

Download Full-text

Elinzanetant (NT-814), a Neurokinin 1,3 Receptor Antagonist, Reduces Estradiol and Progesterone in Healthy Women

The Journal of Clinical Endocrinology & Metabolism ◽

10.1210/clinem/dgab108 ◽

2021 ◽

Author(s):

Steve Pawsey ◽

Edouard Gregory Mills ◽

Elizabeth Ballantyne ◽

Kirsteen Donaldson ◽

Mary Kerr ◽

...

Keyword(s):

Luteal Phase ◽

Hormone Secretion ◽

Reproductive Hormones ◽

Controlled Study ◽

Vasomotor Symptoms ◽

Reproductive Hormone ◽

Novel Therapy ◽

Serum Progesterone ◽

Hormone Levels ◽

Healthy Women

Abstract Context The ideal therapy for endometriosis (EM) and uterine fibroids (UF) would suppress estrogenic drive to the endometrium and myometrium, whilst minimizing vasomotor symptoms and bone loss associated with current treatments. An integrated neurokinin-kisspeptin system involving Substance P and neurokinin B acting at the neurokinin (NK) receptors 1 and 3, respectively, modulates reproductive hormone secretion and represents a therapeutic target. Objective To assess the effects of the novel NK1,3 antagonist elinzanetant on reproductive hormone levels in healthy women. Design Randomized, single-blinded, placebo-controlled study. Participants/Intervention Thirty-three women attended for 2 consecutive menstrual cycles. In each cycle blood samples were taken on days 3/4, 9/10, 15/16 and 21/22 to measure serum reproductive hormones. In cycle 2, women were randomized to receive once daily oral elinzanetant 40, 80, 120 mg or placebo (N=8 or 9 per group). Results Elinzanetant dose-dependently lowered serum luteinizing hormone, estradiol (120 mg median change across cycle: -141.4 pmol/L, P=0.038) and luteal phase progesterone (120 mg change from baseline on day 21/22: -19.400 nmol/L, P=0.046). Elinzanetant 120 mg prolonged the cycle length by median of 7.0 days (P=0.023). Elinzanetant reduced the proportion of women with a luteal phase serum progesterone concentration >30 nmol/L (a concentration consistent with ovulation) in a dose-related manner in cycle 2 (P=0.002). Treatment did not produce vasomotor symptoms. Conclusions NK1,3 receptor antagonism with elinzanetant dose-dependently suppressed the reproductive axis in healthy women, with the 120 mg dose lowering estradiol to potentially ideal levels for UF and EM. As such, elinzanetant may represent a novel therapy to manipulate reproductive hormone levels in women with hormone driven disorders.

Download Full-text

In Utero and Peripubertal Metals Exposure in Relation to Reproductive Hormones and Sexual Maturation and Progression among Boys in Mexico City

10.21203/rs.3.rs-34705/v2 ◽

2020 ◽

Author(s):

Pahriya Ashrap ◽

John D. Meeker ◽

Brisa N. Sánchez ◽

Niladri Basu ◽

Marcela Tamayo-Ortiz ◽

...

Keyword(s):

Sexual Maturation ◽

Pubic Hair ◽

In Utero ◽

Reproductive Hormones ◽

Testicular Volume ◽

Metal Exposure ◽

Reproductive Hormone ◽

Essential Metal ◽

Hormone Levels ◽

Metal Levels

Abstract Background: Endocrine disrupting chemicals (EDCs) such as metals have been reported to alter circulating reproductive hormone concentrations and pubertal development in animals. However, the relationship has rarely been investigated among humans, with the exception of heavy metals, such as Pb and Cd. Our aim was to investigate measures of in utero and peripubertal metal exposure in relation to reproductive hormone levels and sexual maturation and progression among boys from the Early Life Exposure in Mexico to Environmental Toxicants (ELEMENT) cohorts.Methods: Our analysis included 118 pregnant women and their male children from the ELEMENT study. Essential and non-essential metals were measured in urine collected from the mothers during the third trimester of pregnancy and their male children at 8-14 years. Reproductive hormone levels [serum testosterone, estradiol, dehydroepiandrosterone sulfate (DHEA-S), inhibin B, and sex hormone-binding globulin (SHBG)] were measured in blood samples from the children at 8-14 years. We also assessed Tanner stages for sexual maturation (genital, pubic hair development, and testicular volume), at two time points (8–14, 10-18 years). We used linear regression to independently examine urinary metal levels in relation to each peripubertal reproductive hormones adjusting for child age and BMI. Generalized estimation equations (GEEs) were used to evaluate the association of in utero and peripubertal metal exposures with sexual maturation and progression during follow-up based on Tanner staging and testicular volume.Results: In utero and prepubertal concentrations of some urinary metals were associated with increased levels of peripubertal reproductive hormones, especially non-essential metal(loid)s As and Cd (in utero), and Ba (peripubertal) as well as essential metal Mo (in utero) in association with testosterone. More advanced pubic hair developmental stage and higher testicular volume at the early teen visit was observed for boys with higher non-essential metal concentrations, including in utero Al and peripubertal Ba, and essential metal Zn concentration (peripubertal). These metals were also associated with slower pubertal progression between the two visits.Conclusion: These findings suggest that male reproductive development may be associated with both essential and non-essential metal exposure during in utero and peripubertal windows.

Download Full-text

Seasonal variation in urinary and salivary reproductive hormone levels in Amazonian manatees (Trichechus inunguis)

Reproduction Fertility and Development ◽

10.1071/rd13334 ◽

2015 ◽

Vol 27 (7) ◽

pp. 1065 ◽

Cited By ~ 2

Author(s):

Rodrigo S. Amaral ◽

Fernando C. W. Rosas ◽

Vera M. F. da Silva ◽

Laura H. Graham ◽

Priscila Viau ◽

...

Keyword(s):

Amazon Basin ◽

Environmental Parameters ◽

Reproductive Hormones ◽

Seasonal Effect ◽

Reproductive Hormone ◽

Reproductive Seasonality ◽

Hormone Levels ◽

Salivary Testosterone ◽

Aquatic Mammal

The Amazonian manatee (Trichechus inunguis) is a threatened aquatic mammal endemic to the Amazon basin. The aim of this study was to evaluate the urinary and salivary reproductive hormone levels of captive Amazonian manatees collected during two seasons of the year. Salivary samples from four males and urinary and salivary samples from three females were collected during two seasons (March–June and September–November) over two consecutive years. Salivary testosterone in males was measured by radioimmunoassay and reproductive hormones in females (salivary progesterone and oestradiol and urinary progestogens, oestrogens and luteinising hormone) were measured by enzyme immunoassay. The data were analysed in a 2×2 factorial design, where the factors were year and season. There was no effect of year or season for salivary testosterone. All female hormones showed a seasonal effect (higher hormone levels during March–June than September–November) or an interaction between year and season (P < 0.05). These results strongly indicate the existence of reproductive seasonality in Amazonian manatees; however, apparently only females exhibit reproductive quiescence during the non-breeding season. Further long-term studies are necessary to elucidate which environmental parameters are related to reproductive seasonality in T. inunguis and how this species responds physiologically to those stimuli.

Download Full-text

Testicular size development and reproductive hormones in boys and adult males with Noonan syndrome: a longitudinal study

Acta Endocrinologica ◽

10.1530/eje-11-0092 ◽

2011 ◽

Vol 165 (1) ◽

pp. 137-144 ◽

Cited By ~ 21

Author(s):

Carina Ankarberg-Lindgren ◽

Otto Westphal ◽

Jovanna Dahlgren

Keyword(s):

Noonan Syndrome ◽

Reference Population ◽

Reproductive Hormones ◽

Inhibin B ◽

Delayed Puberty ◽

Reproductive Hormone ◽

Adult Males ◽

Early Puberty ◽

Hormone Levels ◽

Testicular Size

ObjectiveTo characterise changes in testicular size and reproductive hormones and to investigate the aetiology of delayed puberty and impaired fertility in males with Noonan syndrome (NS).DesignIn this study, 12 males with NS were longitudinally followed from pre/early puberty until adulthood. Of the 12 males, ten had no medical history other than NS and were divided into two groups, undescended testes (UT), and descended testes (DT) and compared with a reference population.MethodsHormone concentrations in serum were determined by immunoassays and testicular volume was measured using an orchidometer.ResultsBefore puberty, reproductive hormone levels were within the expected range in almost all cases. In some cases, LH, FSH and testosterone and oestradiol (E2) concentrations started to increase during puberty and inhibin B and anti-Müllerian hormone (AMH) declined to subnormal levels. Most of the boys studied had small testes that, in the majority of cases, progressed to normal size in adulthood. No difference in reproductive hormones was observed between the UT and DT groups either during puberty or at adulthood. However, as adults, males with NS had higher LH (5.7 vs 4.0 U/l, P<0.01), FSH (7.1 vs 2.5 U/l, P<0.001), testosterone (18.7 vs 15.6 nmol/l, P<0.01) and E2 (66 vs 46 pmol/l, P<0.001) levels and lower AMH (33 vs 65 pmol/l, P<0.01) and inhibin B (median 108 vs 187 pg/ml, P<0.01) levels than the reference population.ConclusionsIn NS males, both Sertoli and Leydig cell dysfunction is common with reproductive hormone levels deteriorating progressively to adulthood.

Download Full-text

Pubertal development and reproductive hormone levels of singleton ICSI offspring in adolescence: results of a prospective controlled study

Human Reproduction ◽

10.1093/humrep/deaa021 ◽

2020 ◽

Vol 35 (4) ◽

pp. 968-976 ◽

Cited By ~ 3

Author(s):

B Sonntag ◽

N Eisemann ◽

S Elsner ◽

A K Ludwig ◽

A Katalinic ◽

...

Keyword(s):

Pubertal Development ◽

Hormonal Contraception ◽

Reproductive Hormones ◽

Inhibin B ◽

Controlled Study ◽

Age At Menarche ◽

Reproductive Hormone ◽

Hormone Levels ◽

The Mean ◽

Prospective Controlled Study

Abstract STUDY QUESTION Are there any differences in the pubertal development and reproductive hormone status during adolescence between singletons following ICSI therapy or spontaneous conception (SC)? SUMMARY ANSWER Pubertal development and reproductive hormone levels are largely similar between ICSI and SC adolescents, except for a tendency towards lower inhibin B levels as well as significantly higher estradiol levels and a lower testosterone-to-estradiol-ratio in male adolescents. WHAT IS KNOWN ALREADY Previous data are scarce and partly inconclusive regarding pubertal development in female ICSI adolescents as well as demonstrating a tendency towards lower inhibin B serum levels in male ICSI offspring. STUDY DESIGN, SIZE, DURATION Prospective controlled study including 274 singleton ICSI-conceived adolescents (141 girls, 133 boys) followed up for the third time, and 273 SC controls (142 girls, 131 boys) from seven German registration offices (Aachen, Eichstätt, Erfurt, Lübeck, Hamburg, Heidelberg and Schwerin). PARTICIPANTS/MATERIALS, SETTING, METHODS Pubertal development assessed by Tanner staging (breast, genital and pubic hair development), age at menarche and reproductive hormone levels were analyzed in ICSI and SC adolescents at the mean age of 16.5 years. Differences were analyzed by multinomial regression (Tanner stages) or t test and linear regression for hormonal assessments. MAIN RESULTS AND THE ROLE OF CHANCE Both female and male ICSI and SC adolescents showed adequate pubertal maturation according to their age, and the mean age at menarche (at 12.7 versus 12.8 years) was similar. Tanner stages as well did not display any relevant or significant differences between the groups. Reproductive hormone levels in female adolescents not using hormonal contraception were largely similar before and after adjustment for several factors such as preterm birth, Tanner stages, BMI or physical activity. In male ICSI adolescents, a tendency towards lower inhibin B (−14.8 pg/ml, 95% CI: −34.2 to 4.6 pg/ml), significantly higher estradiol (2.6 ng/l, 95% CI: 0.0 to 5.2 ng/l) and a significantly lower testosterone-to estradiol ratio (−0.047, 95% CI: −0.089 to −0.004) was found. LIMITATIONS, REASONS FOR CAUTION The all-over response rate and the willingness to participate in the blood test and medical examination were very low in the control group. Participating control families may have greater health awareness, and selection bias cannot be ruled out. Hormonal data in the females were measured irrespective of the cycle day and restricted to those not using hormonal contraception. Some parameters from the questionnaire data such as usage of hormonal contraception might suffer from reporting bias. As this is an observational study, we can draw only limited causal conclusions from the findings. WIDER IMPLICATIONS OF THE FINDINGS Differences in male reproductive hormones may indicate altered testicular function. However, at this time possible consequences for later reproductive success are unknown. STUDY FUNDING/COMPETING INTEREST(S) DFG research grant KA 1643/4-1. The authors declare no conflict of interest.

Download Full-text

Meat intake in relation to semen quality and reproductive hormone levels among young men in Spain

British Journal Of Nutrition ◽

10.1017/s0007114518003458 ◽

2018 ◽

Vol 121 (4) ◽

pp. 451-460 ◽

Cited By ~ 4

Author(s):

Ana B. Maldonado-Cárceles ◽

Lidia Mínguez-Alarcón ◽

Jaime Mendiola ◽

Jesús Vioque ◽

Niels Jørgensen ◽

...

Keyword(s):

Semen Quality ◽

Linear Trend ◽

Young Men ◽

Reproductive Hormones ◽

Semen Parameters ◽

Reproductive Hormone ◽

Cross Sectional ◽

Significant Linear Trend ◽

Meat Intake ◽

Hormone Levels

AbstractThe aim of this study was to assess the associations of intake of different types of meat with semen parameters and reproductive hormones in healthy young men. This cross-sectional study included 206 men, 18–23 years, from Southern Spain. All men completed a validated FFQ, underwent a physical examination, and provided blood and semen samples. Multivariable linear regression was used to evaluate the associations between meat intake with semen quality parameters and reproductive hormones. Total meat intake was unrelated to semen quality or reproductive hormone levels. When subgroups of meat were separately considered, however, shellfish intake was positively related to progressive motility. The adjusted percentages of progressively motile spermatozoa for men in increasing quartiles of shellfish intake were 45·2, 42·0, 49·4 and 53·2 % with a significant linear trend across quartiles (Ptrend≤0·001). In contrast, men who consumed organ meats had significantly lower progressive sperm motility (51·5 v. 42·8 %; P = 0·001) and higher luteinising hormone levels (4·0 v. 4·6 IU/l; P = 0·03) compared with men who did not consume organ meats. Intake of shellfish and organ meats was low in this population, however. Given the scarcity of data on the relation between specific types of meat with semen quality and reproductive hormone levels, additional research is needed to confirm or refute these findings.

Download Full-text

Use of Gonadotropic Hormones and Sex Steroids in Assessing Male Reproduction

Journal of the American College of Toxicology ◽

10.3109/10915818609140748 ◽

1986 ◽

Vol 5 (4) ◽

pp. 235-247

Author(s):

R. J. Witorsch

Keyword(s):

Anterior Pituitary ◽

Hypogonadotropic Hypogonadism ◽

Reproductive Function ◽

Inhibitory Effect ◽

Progressive Increase ◽

Reproductive Hormones ◽

Male Reproduction ◽

Reproductive Hormone ◽

Age Related ◽

Aging Men

In this presentation we discuss how male reproductive hormones are influenced by various normal and abnormal situations. Puberty is characterized by a progressive increase in serum gonadotropins (FSH and LH) and testosterone. Hormonal profiles in aging men and rats differ significantly, suggesting qualitatively different age-related changes in both species. Gonadal disorders in humans may exhibit similar symptoms (such as delayed or precocious virilization) but may be due to different defects within the hypothalamo-pituitary-testicular axis and, hence, may exhibit different reproductive hormone profiles. Reproductive hormone measurements reveal that toxic agents, such as ketoconazole, alcohol, or opiates, can impair reproductive function at the gonad and/or the hypothalamo-pituitary level. Glucocorticoids released during stress have been shown to have a direct inhibitory effect on testosterone release from the testes, which may be of relevance to toxicology studies. Reproductive hormonal measurements have also revealed that LH levels in the blood fluctuate in a pronounced episodic fashion and that this pattern is due to the pulsatile delivery of GnRH to the anterior pituitary gland. Administration of GnRH in a pulsatile fashion to patients with hypogonadotropic hypogonadism restores gonadal function. Nonpulsatile GnRH delivery to the anterior pituitary suppresses LH and testosterone release, and, consequently, long-acting superanalogs of GnRH appear to be effective in the treatment of prostatic cancer and true precocious puberty. The examples presented in this article illustrate how hormonal measurements have increased our knowledge and understanding of male reproduction.

Download Full-text