Plasma androgen levels during the menstrual cycle

Androgen Excess and Deficiency: Analytical and Diagnostic Approaches

BACKGROUND

Androgens are synthesized from cholesterol through sequential conversions by enzymes in the adrenal glands and gonads. Serum levels of androgens change during the different phases of life and regulate important developmental and maturational processes. Androgen excess or deficiency can therefore present at various ages in various ways.

CONTENT

The diagnostic approach for atypical genitalia, premature pubarche, delayed pubertal onset or progression, and hirsutism or virilization, including measurement of androgens (testosterone, androstenedione, 17-OHprogesterone, dehydroepiandrosterone, and dihydrotestosterone) is discussed in the current review. Androgens can be measured in serum, saliva, urine, or dried blood spots. Techniques to measure androgens, including immunoassays and LC-MS, have their own advantages and pitfalls. In addition, pre- and postanalytical issues are important when measuring androgens.

SUMMARY

During clinical interpretation of androgen measurements, it is important to take preanalytical circumstances, such as time of blood withdrawal, into account. As immunoassays have major drawbacks, especially in samples from women and neonates, concentrations measured using these assays should be interpreted with care. Reference intervals can only be used in relation to the measurement technique and the standardization of the assay. In the near future, new androgens will probably be added to the current repertoire to further improve the diagnosis and follow-up of androgen excess or deficiency.

Androgen signalling in the ovaries and endometrium

Currently, our understanding of hormonal regulation within the female reproductive system is largely based on our knowledge of estrogen and progesterone signalling. However, while the important functions of androgens in male physiology are well known, it is also recognized that androgens play critical roles in the female reproductive system. Further, androgen signalling is altered in a variety of gynaecological conditions, including endometriosis and polycystic ovary syndrome, indicative of regulatory roles in endometrial and ovarian function. Co-regulatory mechanisms exist between different androgens, estrogens, and progesterone, resulting in a complex network of steroid hormone interactions. Evidence from animal knockout studies, in vitro experiments, and human data indicate that androgen receptor expression is cell-specific and menstrual cycle stage-dependent, with important regulatory roles in the menstrual cycle, endometrial biology, and follicular development in the ovaries. This review will discuss the expression and co-regulatory interactions of androgen receptors, highlighting the complexity of the androgen signalling pathway in the endometrium and ovaries, and the synthesis of androgens from additional alternative pathways previously disregarded as male-specific. Moreover, it will illustrate the challenges faced when studying androgens in female biology, and the need for a more in-depth, integrative view of androgen metabolism and signalling in the female reproductive system.

Benefits of Airway Androgen Receptor Expression in Human Asthma

Rationale: Androgens are potentially beneficial in asthma, but AR (androgen receptor) has not been studied in human airways.Objectives: To measure whether AR and its ligands are associated with human asthma outcomes.Methods: We compared the effects of AR expression on lung function, symptom scores, and fractional exhaled nitric oxide (Fe_NO) in adults enrolled in SARP (Severe Asthma Research Program). The impact of sex and of androgens on asthma outcomes was also evaluated in the SARP with validation studies in the Cleveland Clinic Health System and the NHANES (U.S. National Health and Nutrition Examination Survey).Measurements and Main Results: In SARP (n = 128), AR gene expression from bronchoscopic epithelial brushings was positively associated with both FEV₁/FVC ratio (R² = 0.135, P = 0.0002) and the total Asthma Quality of Life Questionnaire score (R² = 0.056, P = 0.016) and was negatively associated with Fe_NO (R² = 0.178, P = 9.8 × 10^-6) and NOS2 (nitric oxide synthase gene) expression (R² = 0.281, P = 1.2 × 10^-10). In SARP (n = 1,659), the Cleveland Clinic Health System (n = 32,527), and the NHANES (n = 2,629), women had more asthma exacerbations and emergency department visits than men. The levels of the AR ligand precursor dehydroepiandrosterone sulfate correlated positively with the FEV₁ in both women and men.Conclusions: Higher bronchial AR expression and higher androgen levels are associated with better lung function, fewer symptoms, and a lower Fe_NO in human asthma. The role of androgens should be considered in asthma management.

Prechemotherapy Levels of Plasma Dehydroepiandrosterone and Its Sulfated Form as Predictors of Cancer-Related Cognitive Impairment in Patients with Breast Cancer Receiving Chemotherapy

Study Objective

Dehydroepiandrosterone (DHEA) and its sulfated form (DHEAS)—jointly referred to as DHEA(S)—are neurosteroids known to regulate brain development and function that have been found to be positively correlated with cognitive function. It is unknown whether prechemotherapy plasma DHEA(S) levels are associated with the onset of cancer‐related cognitive impairment (CRCI). The objective of this study was to evaluate whether an association exists between prechemotherapy plasma DHEA(S) levels and onset of CRCI in patients with breast cancer receiving chemotherapy.

Design

Multicenter, prospective cohort study.

Setting

Two specialized cancer centers in Singapore.

Patients

Eighty‐one patients with early‐stage breast cancer (stages I–III) who had no prior exposure to chemotherapy and/or radiotherapy and were scheduled to receive anthracycline‐based or taxane‐based chemotherapy treatment with curative intent.

Measurements and Main Results

Patients completed assessments for self‐perceived and objective cognitive function at three time points: prechemotherapy (T1), during chemotherapy (T2), and after chemotherapy (T3). Plasma samples were collected prior to chemotherapy, and DHEA(S) levels were quantified by using ultra–high‐performance liquid chromatography–tandem mass spectrometry. Multivariable logistic regression was used to adjust for clinically important factors and to evaluate the association between prechemotherapy plasma DHEA(S) levels and CRCI. Mean ± SD age was 48.9 ± 9.3 years, with 27.8% of patients experiencing clinically significant cognitive impairment based on global Functional Assessment of Cancer Therapy–Cognitive Function scores. The mean ± SD prechemotherapy plasma DHEAS and DHEA levels were 1.61 ± 0.91 μmol/L and 19.21 ± 13.13 nmol/L, respectively. Prechemotherapy DHEAS levels were found to be associated with impairment in the self‐perceived cognitive domains of verbal fluency (adjusted odds ratio [OR] 0.27, 95% confidence interval [CI] 0.08–0.96) and mental acuity (adjusted OR 0.25, 95% CI 0.08–0.74). Conversely, DHEA levels were not associated with impairment in any cognitive subdomains.

Conclusion

Our findings suggest that patients with higher prechemotherapy DHEAS levels had lower odds of developing self‐perceived cognitive impairment. Future studies are required to further investigate the effect of DHEA(S) on specific cognitive domains and to validate our findings in independent cohorts.

Circulating androgens and SHBG during the normal menstrual cycle in two ethnic populations

The objective of this study was to study possible ethnic differences in steroid hormones and sex hormone-binding globulin (SHBG) during the menstrual cycle. Serum levels of the ovarian steroids estradiol (E2) and progesterone (P) and of follicle-stimulating hormone (FSH), luteinizing hormone (LH), SHBG, dehydroepiandrosterone (DHEA) and testosterone (T-ria) were all measured by immunoassay during the menstrual cycle in 15 Swedish and 11 West Asian regularly menstruating women. Testosterone (T-ms) was also measured by LC-MS/MS and so were 4-androstene-3,17-dione (A-4) and 17-alpha-hydroxyprogesterone (17-OHP). There were no ethnic differences in levels of ovarian steroids, gonadotrophins, A-4, 17-OHP and T-ms. DHEA were significantly higher and SHBG significantly lower in West Asian than in Swedish women. Surprisingly, T-ria was significantly higher in West Asian than in Swedish women and higher than T-ms (47% in Swedish and 107% in West Asian women). The difference (T-ria - T-ms) showed strong positive correlations to DHEA in the total and in West Asian but not in Swedish women, indicating an influence of DHEA/DHEAS metabolites on the T-ria results. In conclusion, ethnic differences in cross reacting steroids may cause erroneous results in one ethnic group by a steroid immunoassay having reasonable specificity in another. The reasons for the lower SHBG and the higher DHEA levels in West Asian women are not known. The results raise the question about establishing different reference values for certain analytes in different ethnic groups.

Inhibin-B secretion and FSH isoform distribution may play an integral part of follicular selection in the natural menstrual cycle

The aim of the present paper is to expand the concept on how follicular selection takes place in the follicular phase of the natural menstrual cycle. It is suggested that inhibin-B exerts a more intimate role in this process than previously understood. Inhibin-B shows a peak in the circulation around cycle day 7, simultaneous with selection of the dominant follicle, whereas levels of estradiol and inhibin-A only start to increase a few days later suggesting that inhibin-B is mainly responsible for downregulating pituitary FSH release. New data now demonstrate that the circulatory peak of inhibin-B is reflected by peak production of inhibin-B, in contrast to inhibin-A, in the selected follicle with a diameter of 10-12 mm, where concentrations are one thousand times higher than in the circulation. This high inhibin-B concentration also exerts paracrine effects, stimulating theca cell androgen production in concert with LH. New data now suggest that in the corresponding granulosa cells androgens upregulate FSH receptor (FSHR) and LH receptor (LHR) mRNA expression, which in turn stimulate CYP19a mRNA expression providing the follicles which most effectively undertake these processes with the best chance of becoming selected. Inhibin-B production is stimulated by FSH and it appears that the acidic isoforms of FSH induce inhibin-B secretion most efficiently thereby, for the first time, placing the changing FSH isoform profile during the follicular phase in a physiological context. Collectively, it appears that inhibin-B is an integral part of follicular selection in the normal menstrual cycle, exerting both endocrine and paracrine effects and facilitating continued growth of the selected follicle.

Cyclic decidualization of the human endometrium in reproductive health and failure

Decidualization denotes the transformation of endometrial stromal fibroblasts into specialized secretory decidual cells that provide a nutritive and immunoprivileged matrix essential for embryo implantation and placental development. In contrast to most mammals, decidualization of the human endometrium does not require embryo implantation. Instead, this process is driven by the postovulatory rise in progesterone levels and increasing local cAMP production. In response to falling progesterone levels, spontaneous decidualization causes menstrual shedding and cyclic regeneration of the endometrium. A growing body of evidence indicates that the shift from embryonic to maternal control of the decidual process represents a pivotal evolutionary adaptation to the challenge posed by invasive and chromosomally diverse human embryos. This concept is predicated on the ability of decidualizing stromal cells to respond to individual embryos in a manner that either promotes implantation and further development or facilitates early rejection. Furthermore, menstruation and cyclic regeneration involves stem cell recruitment and renders the endometrium intrinsically capable of adapting its decidual response to maximize reproductive success. Here we review the endocrine, paracrine, and autocrine cues that tightly govern this differentiation process. In response to activation of various signaling pathways and genome-wide chromatin remodeling, evolutionarily conserved transcriptional factors gain access to the decidua-specific regulatory circuitry. Once initiated, the decidual process is poised to transit through distinct phenotypic phases that underpin endometrial receptivity, embryo selection, and, ultimately, resolution of pregnancy. We discuss how disorders that subvert the programming, initiation, or progression of decidualization compromise reproductive health and predispose for pregnancy failure.

The role of androgens and the androgen receptor in cycling endometrium

Androgens and the androgen receptor (AR) are not only required for male reproductive function, they are also essential for female reproductive physiology. Widely expressed in female reproductive tissues, AR levels fluctuate in a regulated manner in the cycling endometrium. Female androgen production depends on the adrenal glands and expression of key enzymes in the endometrium that facilitate local androgen biosynthesis and conversion. Moreover, levels of circulating androgens, in women of reproductive age, fluctuate in a cycle-dependent manner and a mid-cycle peak is associated with conception. AR and androgen signalling have a decisive role in the differentiation of human endometrial stromal cells into decidual cells. Compelling evidence for androgen signalling in the regulation of endometrial function pertaining to implantation and pregnancy is provided by epidemiological studies demonstrating a strong association between polycystic ovary syndrome, premature ovarian failure or advanced maternal age and adverse pregnancy outcome. Thus, androgen signalling is an essential component of normal endometrial physiology and its perturbation is associated with reproductive failure.

Androgenic hormones and aging--the link with female sexual function

In women, sexual function, hormones and aging are inextricably related. Sexual activity in women involves interest and motivation, the ability to become aroused and achieve orgasm, the pleasure of the experience and subsequent personal satisfaction. Androgens, as endogenous hormones or given as a therapy, potentially influence female sexual function, with research into the effects of exogenous androgens in women mostly devoted to effects on sexual desire. Some studies have been conducted to delineate the effects of testosterone on arousal, however arousal determined by laboratory measures does not always correlate with subjective reporting of a sensation of arousal. Overall large randomised controlled trials of exogenous testosterone show benefits over placebo on sexual desire, arousal, orgasm, pleasure and satisfaction. The aspects of consideration of androgen therapy for women that continue to stimulate debate in this therapeutic area include whether female sexual dysfunction is a condition that merits pharmacotherapy, how effective is such treatment and whether testosterone therapy is safe.

Menstrual irregularity and bone mass in premenopausal women: cross-sectional associations with testosterone and SHBG

Background

There have been few studies examining the associations between menstrual irregularity, androgens and bone mass in population-based samples of premenopausal women. This study aimed to describe the associations between menstrual pattern, testosterone, sex hormone binding globulin (SHBG) and bone mass in a population-based sample of premenopausal women.

Methods

Cross-sectional study (N = 382, mean age 31.5 years). Menstrual pattern was assessed by questionnaire, bone mass measured by quantitative ultrasound (QUS) and androgen status was assessed by levels of serum testosterone, SHBG and the free androgen index (FAI).

Results

Women with irregular cycles (n = 41, 11%) had higher free androgen index (FAI, P = 0.01) and higher QUS measurements including speed of sound (SOS, 1%, P < 0.05), quantitative ultrasound index (QUI, 7%, p < 0.05), and broadband ultrasound attenuation (BUA, 7%, p = 0.10). These associations persisted after adjustment for age and body mass index (BMI). After further adjustment for hormonal factors (either testosterone, SHBG or FAI), the strength of the associations was moderately attenuated, however, women with irregular cycles still had a 6% increase in mean QUS. Total testosterone, FAI and SHBG were also associated with QUS measures (testosterone and FAI, r +0.11 to +0.21, all p < 0.05; SHBG r -0.14 to -0.16, all p < 0.05) and the associations remained significant after adjustment.

Conclusion

Irregular menstrual cycles were associated with higher bone mass in this population-based sample of premenopausal women suggesting menstrual disturbance should continue to be evaluated but may be less harmful for bone mass. The association between menstrual irregularity and bone mass was partially mediated by markers of androgen status especially free testosterone.

Obesity and menstrual irregularity: associations with SHBG, testosterone, and insulin

This cross-sectional study aimed to examine the association between different body composition measures, menstrual cycle characteristics, and hormonal factors in a population-based sample of young women. The study sample included 726 Australian women aged 26-36 years who were not currently taking hormonal contraceptives and were not currently pregnant or breast feeding. Anthropometric measures included BMI, waist circumference (WC), and waist-hip ratio (WHR). Menstrual cycle characteristics were self-reported and usual cycles defined as short (<or=25 days), normal (26-34 days), or long (>or=35 days). Cycles were defined as irregular if there were >or=15 days between the longest and shortest cycle in the past 12 months. Fasting serum levels of sex hormone-binding globulin (SHBG), testosterone, insulin, and glucose were measured and the free androgen index (FAI) derived. Compared with those of normal weight, obese women had at least a twofold greater odds of having an irregular cycle, whether defined by BMI (odds ratio (OR) = 2.61; 95% CI = 1.28-5.35), WC (OR 2.28; 95% CI = 1.16-4.49), or WHR (OR = 2.27; 95% CI = 1.09-4.72). Body composition measures were significantly positively associated with fasting insulin, testosterone, and FAI, and negatively associated with SHBG (P < 0.01). Fasting insulin, SHBG, and FAI had the strongest influence on the associations between obesity and irregular cycles, with statistically significant ORs of having an irregular cycle being attenuated to near null values following adjustment. In conclusion, both overall and central obesity were significantly associated with having an irregular menstrual cycle. This association was substantially influenced by hormonal factors, particularly insulin and SHBG.

Quantitative analysis of DHEA and androsterone in female urine: investigating the effects of menstrual cycle, oral contraception and training on exercise-induced changes in young women

Dehydroepiandrosterone (DHEA) and its metabolite androsterone (A) are natural steroids secreted in high quantities in human body. To assess the influence of oral contraceptives, menstrual cycle phase, and also physical exercise (acute and chronic such as training) on these metabolites excretions, a collection of 28 female urine specimens was organized. A three-extraction-step method was developed, and the analyses were performed by gas chromatography-mass spectrometry using deuterated 19-noretiocholanolone as the internal standard. Sample hydration state was found to be of great importance for kinetic studies, as it directly influenced the concentrations. No influence of menstrual cycle and training was found for androsterone and DHEA. However, oral contraceptive intake lowered DHEA excretion in urine and A seems to be slightly affected by exercise.

Biological factors and the determination of androgens in female subjects

The idea of the presence of androgens in females may sound peculiar as androgens generally refer to male hormones. Although produced in small amounts in women, androgens have direct and significant effects on many aspects of female physiology. Moreover, androgens are precursors to estrogens, which are the predominant female sex hormones. The measurement of androgens in blood is important in the diagnosis of both gonadal and adrenal functional disturbances, as well as monitoring subsequent treatments. The accuracy of such measurements is crucial in sports medicine and doping control. Therefore, the concentration of androgens in female subjects is frequently measured. Analysing such compounds with accuracy is especially difficult, costly and time consuming. Therefore, laboratories widely use direct radioimmunoassay kits, which are often insensitive and inaccurate. It is especially complicated to determine the level of androgens in women, as the concentration is much lower compared to the concentration found in males. Additionally, the amount of androgens in fluids tends to decrease with aging. Analyses of hormone concentrations are influenced by a myriad of factors. The factors influencing the outcome of these tests can be divided into in vivo preanalytical factors (e.g., aging, chronobiological rhythms, diet, menstrual cycle, physical exercise, etc.), in vitro preanalytical factors (e.g., specimen collection, equipment, transport, storage, etc.) and as mentioned before, analytical factors. To improve the value of these tests, the strongly influencing factors must be controlled. This can be accomplished using standardised assays and specimen collection procedures. In general, sufficient attention is not given to the preanalytical (biological) factors, especially in the measurement of androgens in females. Biological factors (non-pathological factors) that may influence the outcome of these tests in female subjects have received little attention and are the topic of the present review.

Sex hormone-binding globulin and androgen levels in immigrant and British-born premenopausal British Pakistani women: Evidence of early life influences?

In women, raised insulin levels are associated with low sex hormone-binding globulin (SHBG) and high androgen levels, which are in turn linked to infertility. Since insulin resistance and hyperinsulinemia are major health problems for South Asians living in Western countries, we predicted that British Pakistani women would have low SHBG and raised androgen levels compared to European women. Given low birth weights in Pakistan, and known links between low birth weight and insulin resistance in later life, we also predicted that immigrant women born in Pakistan would have lower levels of SHBG and higher levels of androgens than British-born British Pakistani women. We assessed SHBG, testosterone, and the free androgen index (FAI) from a single serum sample taken on days 9-11 of the menstrual cycle from 20-40-year-old women living in the UK: 30 immigrants from Pakistan, 30 British-born British Pakistani women, and 25 British-born women of European origin. Age-adjusted analyses showed no significant differences in SHBG, testosterone, or FAI between British-born Pakistani and European-origin women. However, immigrant British Pakistani women had a significantly higher FAI than British-born British Pakistani women. Adjustment for body mass index, waist-to-hip ratio, and smoking status did not affect these results, but further adjustment for height, a marker of early environment, reduced the P-value for the difference in FAI between immigrant and British-born British Pakistani women to below significance. It is possible that the poorer early environment of immigrant British Pakistani women was at least partially responsible for their relatively high levels of free androgens.

Androgen replacement therapy in women

OBJECTIVE

Review of literature with regard to androgen replacement therapy in women.

DESIGN

Review of the MEDLINE database and references from articles.

CONCLUSIONS

Androgens affect sexual function, bone health, muscle mass, body composition, mood, energy, and the sense of well-being. Androgen insufficiency clearly has been demonstrated in patients with hypopituitarism, adrenalectomy, oophorectomy, and in some women placed on oral estrogen therapy which increases sex hormone-binding globulin (SHBG) levels and lowers the free and bioavailable forms of T. Symptoms of androgen insufficiency in women may include a diminished sense of well-being, low mood, fatigue, and hypoactive sexual desire disorder with decreased libido, or decreased sexual receptivity and pleasure that causes a great deal of personal distress. The preponderance of evidence from clinical trials supports the correlation of decreased endogenous androgen levels with these symptoms and alleviation of many of the symptoms with the administration of T or, in some cases, DHEA. There are no Food and Drug Administration-approved androgen preparations on the market for treating androgen insufficiency in women. The safety profile of androgens in doses used for the treatment of hypoactive sexual desire disorder has been excellent with only mild acne and hirsutism being noted in a minority of patients.

Salivary testosterone is related to both handedness and degree of linguistic lateralization in normal women

The aim of this study was to test the hypothesis that individual differences in testosterone (T) are associated with different patterns of linguistic lateralization and hand preference. Twenty left-handed (LH) and 19 right-handed (RH) women filled in a handedness questionnaire and performed a consonant-vowel dichotic listening test (DL-CV). Salivary T was measured by radioimmunoassay (RIA). LH women showed significantly lower mean salivary T than RH women. T levels were negatively correlated with the absolute value of the DL laterality index. Subjects with right ear advantage (REA) were classified into strongly and weakly lateralized following Wexler et al. method (Brain Lang. 13 (1981) 13). When taking into account hand preference, a pattern emerged in that RH-strongly lateralized and LH-weakly lateralized women showed similar T levels. The lowest level appeared for LH-strongly lateralized women and the highest for RH-weakly lateralized women, being significantly different from each other. The results are discussed in terms of several theories that have proposed a link between testosterone and cerebral lateralization.

Effects of ovarian hormones on human cortical excitability

Ovarian steroids appear to alter neuronal function in women, but direct physiological evidence is lacking. In animals, estradiol enhances excitatory neurotransmission. Progesterone-derived neurosteroids increase GABAergic inhibition. The effect of weak transcranial magnetic stimulation of the motor cortex on the motor evoked potential (MEP) from transcranial magnetic stimulation given milliseconds later is changed by GABAergic and glutamatergic agents. Using this technique previously, we showed more inhibition in the luteal phase relative to the midfollicular menstrual phase, which is consistent with a progesterone effect. To detect the effects of estradiol, we have now divided the follicular phase. We tested 14 healthy women during the early follicular (low estradiol, low progesterone), late follicular (high estradiol, low progesterone), and luteal (high estradiol, high progesterone) phases, with interstimulus intervals from 2 to 10msec (10 trials at each interval and 40 unconditioned trials). We calculated the ratio of the conditioned MEP at each interval to the mean unconditioned MEP: the higher the ratio, the less inhibition and the more facilitation caused by the first stimulus. The combined ratios increased significantly from the early follicular phase to the late follicular phase and then decreased again in the luteal phase. These findings demonstrate an excitatory neuronal effect associated with estradiol and confirm our earlier finding of inhibition associated with progesterone.

Androgen insufficiency in women: summary of critical issues

Critical issues concerning the role of androgens in the physical, sexual, and emotional health of women include the following:1. Which androgens best reflect the androgen status of women? 2. What form of T should be measured and how? 3. Do T levels fall after menopause? 4. What effect does oophorectomy have on T levels? 5. What is the relationship between T and sexual dysfunction? 6. What constitutes androgen insufficiency syndrome? 7. What conditions are associated with androgen insufficiency? 8. How should a patient with suspected androgen insufficiency be evaluated? 9. Does androgen replacement therapy improve sexual dysfunction? 10. Do androgens enhance the quality of life? 11. Is estrogen and androgen therapy superior to estrogen therapy alone for low bone mineral density? 12. What are the indications for androgen replacement therapy? 13. What is the best means for delivery of androgen therapy? 14. How should androgen replacement therapy be monitored? Based on our current knowledge, it is clear that some women develop symptomatic androgen insufficiency and that androgen replacement therapy has a beneficial effect on libido, sexual satisfaction, quality of life, and bone mineralization. Androgen replacement therapy should be given the same consideration that we give estrogen replacement therapy.

Sex steroids and human behavior: implications for developmental psychopathology

In a variety of mammalian species, prenatal androgens organize brain structures and functions that are later activated by steroid hormones in postnatal life. In humans, studies of individuals with typical and atypical development suggest that sex differences in reproductive and nonreproductive behavior derive in part from similar prenatal and postnatal steroid effects on brain development. This paper provides a summary of research investigating hormonal influences on human behavior and describes how sex differences in the prevalences and natural histories of developmental psychopathologies may be consistent with these steroid effects. An association between patterns of sexual differentiation and specific forms of psychopathology suggests novel avenues for assessing the effects of sex steroids on brain structure and function, which may in turn improve our understanding of typical and atypical development in women and men.

The role of androgens in female vertebrates

The role of androgens in vertebrate females has been overlooked until recently. We examine the functional significance of androgens in females by reviewing studies that document relatively high levels of circulating plasma androgens, androgen receptors, or androgen-metabolizing enzymes in females. Among the mechanisms of androgenic action identified are enhanced neuron survival, stimulation of muscle satellite cell proliferation, alteration of ion current kinetics, and release of somatostatin. These mechanisms are not sex specific and thus we hypothesize that androgens play a significant role in normal female development. We encourage study in this nontraditional research area.

Salivary testosterone levels in left- and right-handed adults

It has been proposed that prenatal testosterone (T) may contribute to the development of hand preference and cerebral functional asymmetry in humans. To investigate any persisting association between T and asymmetry in adulthood, left-handed (LH) and right-handed (RH) men and women were administered a hand preference questionnaire and the Fused Dichotic Words Test. Testosterone was measured in samples of saliva. Results showed that LH subjects of both sexes had lower salivary T concentrations than their RH counterparts. Among LH males, subjects with a right-ear advantage in dichotic listening tended to have lower T concentrations than subjects with a left-ear advantage. These results are consistent with the notion that T may be involved in the development of hand preference and cerebral functional asymmetry.

Androgens and sexuality

A review of the literature reveals that the endocrine determinants of female sexuality are complex and difficult to characterize. In adolescent males, free testosterone directly affects sexual motivation, with social factors exerting little or no effect. In adolescent girls, by contrast, societal and peer pressure play a pivotal role in the appearance of certain sexual behaviors. Throughout a woman's life, hormonal and psychosocial factors are critical influences. It is possible that cyclic patterns of testosterone are less important for female sexual behavior than the "tonic" effect of overall testosterone levels. Although the estrogen dependence of the vaginal epithelium--important for postmenopausal women--has been clearly established, the role of other hormonal factors and treatments, particularly those involving androgens, in human female sexual behavior remains enigmatic. The search for an understanding of these relationships is not merely an interesting academic exercise but is necessary to determine what role, if any, androgens may play in the treatment of sexual dysfunction during the female reproductive years.

Premenstrual syndrome

The Premenstrual Syndrome (PMS) was described as a unique entity meriting therapeutic attention in 1931. Although researchers in the area have failed to develop a widely accepted definition of PMS, substantial progress has been made in describing the variety of psychobiological profiles encompassed by this syndrome, particularly with respect to its typical symptoms, cyclical nature, symptoms recurrence and severity. Therapies ranging from diet and exercise to vitamin, hormone and drug treatment have been proposed. While none is more efficacious than placebo, several have been popularized. Our failure to develop adequate treatment may reflect our lack of understanding of either the psychosocial or biological factors involved in PMS. This, in turn, may reflect inadequate theoretical development in this research area. We provide a critical assessment of research on PMS, suggest a framework for theoretical development and advocate research strategies that might provide insights into the etiology of the premenstrual syndrome.

Salivary testosterone measurements: reliability across hours, days, and weeks

Salivary testosterone measurements would appear to be useful in behavioral research, where subjects are often reluctant to provide serum samples. The usefulness of salivary measurements depends upon their reliability, however, which was the focus of the present investigation. In four studies, 270 male and 175 female subjects collected saliva samples at times ranging from 30 min to 8 weeks apart. Subjects collected samples on at least two days, at time of awakening, midmorning, late afternoon, and late evening. Mean testosterone concentration dropped about 50% from morning to evening for both sexes, with largest drops early in the day. Mean reliability was r = .64 across two days and r = .52 across seven-eight weeks. Menstrual cycle effects were negligible. Reliability can be increased by using more than one measurement, and it is probably desirable to combine measurements taken several weeks apart. Salivary assays offer a practical way of measuring testosterone in free-ranging subjects outside the laboratory.

Adrenal and gonadal androgen secretion in normal females

Both the adrenal and the ovary contain the biosynthetic pathways necessary for androgen synthesis and secretion. The fetal ovary is not very active but the fetal adrenal is an important source of DHAS. However the secretion of DHAS declines markedly after birth and until puberty there is little androgen secretion by either the adrenal or the ovary. Post-pubertally, the adrenal secretes DHAS, DHA, delta 4-A and T from the reticularis and probably the fasciculata. This secretion is under ACTH control, at least in part, but apparently also under control of another pituitary polypeptide tentatively called 'adrenal androgen secretory hormone'. THe adrenal secretion rates are in the range of 7-14 mg/day for DHAS, 3-4 mg/day for DHA, 1-1.5 mg/day for delta 4-A and 50 micrograms/day for T. Androgen secretion from the ovary arises in part from the theca cells of the follicle, the corpus luteum and the stromal cells, under LH control, and will vary somewhat during the normal menstrual cycle. The ovarian secretion rate in the follicular phase is 1-2 mg/day for DHA, 1-1.5 mg/day for delta 4-A and about 50 micrograms/day for T. In the peri-ovulatory period the secretion rate of delta 4-A can rise to 3-3.5 mg/day but there appears to be little change in the secretion of DHA and T. The normal ovary does not secrete significant amounts of DHAS. In about 50% of post-menopausal women the ovaries continue to secrete some T but little delta 4-A or DHA.

Testosterone-estradiol-binding globulin, unbound and total estradiol and testosterone, and total progesterone during the menstrual cycle in women with epilepsy taking antiepileptic drugs

Total plasma estradiol, progesterone, testosterone, and the binding capacity of testosterone-estradiol-binding globulin (TeBG) were measured and plasma unbound estradiol and testosterone calculated, every second day during nine cycles in six patients with epilepsy. They all received phenytoin as one medication. Some had additionally, phenobarbital or ethosuximide. Plasma concentrations were compared with those of a group of healthy women without medication. Total plasma testosterone and TeBG binding capacity were significantly increased in the treated group, as compared to the control group. However, the unbound testosterone concentration was within the range of the controls. The percentage unbound testosterone of total plasma concentration was clearly below that of the control group. This indicates that there was a primarily increased TeBG binding capacity in patients taking antiepileptic drugs.

Changed levels of endogenous sex steroids in women on oral contraceptives

Serum and urinary levels of unconjugated testosterone, dihydrotestosterone, and oestradiol were measured by specific radioimmunoassays in 10 healthy women in the early follicular phase of their menstrual cycle and in nine healthy women taking oral contraceptives. The contraceptive group had testosterone levels 1-3 times higher and dihydrotestosterone levels two times higher than those in the controls. Serum oestradiol levels in the contraceptive group were much lower than those in the controls and similar to levels in postmenopausal women. The contraceptive group had about twice the urinary excretion of unconjugated (free) testosterone and dihydrotestosterone of the controls, but their excretion of unconjugated oestradiol was 2-7 times lower. The great increase in serum and urinary androgen concentrations, as well as the suppression of oestradiol, may be related to the antiovulatory effect of oral contraceptives.