Biochemical roles of testosterone and epitestosterone to 5 alpha-reductase as indicators of male-pattern baldness

Still little evidence sex differences in spatial navigation are evolutionary adaptations

A putative male advantage in wayfinding ability is the most widely documented sex difference in human cognition and has also been observed in other animals. The common interpretation, the sex-specific adaptation hypothesis, posits that this male advantage evolved as an adaptive response to sex differences in home range size. A previous study a decade ago tested this hypothesis by comparing sex differences in home range size and spatial ability among 11 species and found no relationship. However, the study was limited by the small sample size, the lack of species with a larger female home range and the lack of non-Western human data. The present study represents an update that addresses all of these limitations, including data from 10 more species and from human subsistence cultures. Consistent with the previous result, we found little evidence that sex differences in spatial navigation and home range size are related. We conclude that sex differences in spatial ability are more likely due to experiential factors and/or unselected biological side effects, rather than functional outcomes of natural selection.

Genetic analyses implicate complex links between adult testosterone levels and health and disease

BACKGROUND

Testosterone levels are linked with diverse characteristics of human health, yet, whether these associations reflect correlation or causation remains debated. Here, we provide a broad perspective on the role of genetically determined testosterone on complex diseases in both sexes.

METHODS

Leveraging genetic and health registry data from the UK Biobank and FinnGen (total N = 625,650), we constructed polygenic scores (PGS) for total testosterone, sex-hormone binding globulin (SHBG) and free testosterone, associating these with 36 endpoints across different disease categories in the FinnGen. These analyses were combined with Mendelian Randomization (MR) and cross-sex PGS analyses to address causality.

RESULTS

We show testosterone and SHBG levels are intricately tied to metabolic health, but report lack of causality behind most associations, including type 2 diabetes (T2D). Across other disease domains, including 13 behavioral and neurological diseases, we similarly find little evidence for a substantial contribution from normal variation in testosterone levels. We nonetheless find genetically predicted testosterone affects many sex-specific traits, with a pronounced impact on female reproductive health, including causal contribution to PCOS-related traits like hirsutism and post-menopausal bleeding (PMB). We also illustrate how testosterone levels associate with antagonistic effects on stroke risk and reproductive endpoints between the sexes.

CONCLUSIONS

Overall, these findings provide insight into how genetically determined testosterone correlates with several health parameters in both sexes. Yet the lack of evidence for a causal contribution to most traits beyond sex-specific health underscores the complexity of the mechanisms linking testosterone levels to disease risk and sex differences.

Alterations in Pattern Baldness According to Sex: Hair Metabolomics Approach

Pattern baldness has been associated with the male hormone, dihydrotestosterone. In this study, we tried to determine how the overall metabolic pathways of pattern baldness differ in patients and in normal controls. Our study aimed to identify alterations in hair metabolomic profiles in order to identify possible markers of pattern baldness according to sex. Untargeted metabolomics profiling in pattern baldness patients and control subjects was conducted using ultra-performance liquid chromatography-mass spectrometry. To identify significantly altered metabolic pathways, partial least squares discriminant analysis was performed. Our analysis indicated differences in steroid biosynthesis pathway in both males and females. However, there was a remarkable difference in the androgen metabolic pathway in males, and the estrogen metabolic and arachidonic acid pathways in females. For the first time, we were able to confirm the metabolic pathway in pattern baldness patients using hair samples. Our finding improves understanding of pattern baldness and highlights the need to link pattern baldness and sex-related differences.

Untargeted Metabolomics and Steroid Signatures in Urine of Male Pattern Baldness Patients after Finasteride Treatment for a Year

Male pattern baldness (MPB) has been associated with dihydrotestosterone (DHT) expression. Finasteride treats MPB by inhibiting 5-alpha reductase and blocking DHT production. In this study, we aimed to identify metabolic differences in urinary metabolomics profiles between MPB patients after a one-year treatment with finasteride and healthy controls. Untargeted and targeted metabolomics profiling was performed using liquid chromatography-mass spectrometry (LC-MS). We hypothesized that there would be changes in overall metabolite concentrations, especially steroids, in the urine of hair loss patients treated with finasteride and normal subjects. Untargeted analysis indicated differences in steroid hormone biosynthesis. Therefore, we conducted targeted profiling for steroid hormone biosynthesis to identify potential biomarkers, especially androgens and estrogens. Our study confirmed the differences in the concentration of urinary androgens and estrogens between healthy controls and MPB patients. Moreover, the effect of finasteride was confirmed by the DHT/T ratio in urine samples of MPB patients. Our metabolomics approach provided insight into the physiological alterations in MPB patients who have been treated with finasteride for a year and provided evidence for the association of finasteride and estrogen levels. Through a targeted approach, our results suggest that urinary estrogens must be studied in relation to MPB and post-finasteride syndrome.

Sex-related differences in urinary immune-related metabolic profiling of alopecia areata patients

INTRODUCTION

Alopecia areata is a well-known autoimmune disease affecting humans. Polyamines are closely associated with proliferation and inflammation, and steroid hormones are involved in immune responses. Additionally, bile acids play roles in immune homeostasis by activating various signaling pathways; however, the roles of these substances and their metabolites in alopecia areata remain unclear.

OBJECTIVES

In this study, we aimed to identify differences in metabolite levels in urine samples from patients with alopecia areata and healthy controls.

METHODS

To assess polyamine, androgen, and bile acid concentrations, we performed high-performance liquid chromatography-tandem mass spectrometry.

RESULTS

Our results showed that spermine and dehydroepiandrosterone levels differed significantly between male patients and controls, whereas ursodeoxycholic acid levels were significantly higher in female patients with alopecia areata than in controls.

CONCLUSION

Our findings suggested different urinary polyamine, androgen, and bile acid concentrations between alopecia areata patients and normal controls. Additionally, levels of endogenous substances varied according to sex, and this should be considered when developing appropriate treatments and diagnostic techniques. Our findings improve our understanding of polyamine, androgen, and bile acid profiles in patients with alopecia areata and highlight the need to consider sex-related differences.

Altered polyamine profiling in the hair of patients with androgenic alopecia and alopecia areata

Hair follicles are among the most highly proliferative tissues. Polyamines are associated with proliferation, and several polyamines including spermidine and spermine play anti-inflammatory roles. Androgenic alopecia results from increased dihydrotestosterone metabolism, and alopecia areata is an autoimmune disease. This study aimed to investigate differences in polyamine profiles in hair samples between patients with androgenic alopecia and alopecia areata. Polyamine concentrations were determined through high-performance liquid chromatography-mass spectrometry. Hair samples were derivatized with isobutyl chloroformate. Differences in polyamine levels were observed between androgenic alopecia and alopecia areata compared with normal controls. In particular, polyamine levels were higher in alopecia areata patients than in normal controls. Certain polyamines displayed different concentrations between the androgenic alopecia and alopecia areata groups, suggesting that some polyamines, particularly N-acetyl putrescine (P = 0.007) and N-acetyl cadaverine (P = 0.0021), are significantly different in androgenic alopecia. Furthermore, spermidine (P = 0.021) was significantly different in alopecia areata. Our findings suggest that non-invasive quantification of hair polyamines may help distinguish between androgenic alopecia and alopecia areata. Our study provides novel insights into physiological alterations in patients with androgenic alopecia and those with alopecia areata and reveals some differences in polyamine levels in hair loss diseases with two different modes of action.

Simultaneous determination of androgens and prostaglandins in human urine using ultra-high-performance liquid chromatography-tandem mass spectrometry

A simultaneous quantitative profiling method for androgens and prostaglandins using ultra-high-performance liquid chromatography-tandem mass spectrometry was developed and validated to evaluate urinary androgen and prostaglandin levels. Solid-phase extraction and liquid-liquid extraction steps were combined during the sample preparation. β-Glucuronidase/arylsulfatase was also used in the enzyme hydrolysis step. Chemical derivatization was performed using 2-hydrazinopyridine for simultaneous determination of androgen and prostaglandin in the same ionization mode. The analytes were all separated and measured using multiple reaction monitoring in the positive ion mode within a run time of 22 min. The method was validated, achieving overall recoveries ranging from 81.0 to 102.9% with limits of quantification ranging from 0.01 to 2 ng/mL. The intra-day accuracy and precision ranged from 6.5 to 14.3% and from 77.1 to 106.8%, respectively. The inter-day accuracy and precision ranged from 8.9 to 18.2% and 89.9 to 101.4%, respectively. The linearity was expressed using the correlation coefficient, which was >0.99. The method developed herein was used to investigate the effects of a one-year finasteride treatment through differences in urinary androgen and prostaglandin levels between treated male pattern baldness patients and normal controls. The urinary androgen and prostaglandin levels were not significantly different between the two groups because of the administration of finasteride. The results confirmed that finasteride affects androgens and PGs related to hair regrowth and growth length, and a one-year finasteride treatment is effective for MPB. The mass spectrometry-based quantitative profiling method used herein for the investigation of male pattern baldness also holds great potential for the evaluation of androgens and prostaglandins associated with the metabolism of various inflammatory diseases.

Epitestosterone- and testosterone-replacement in immature castrated rats changes main testicular developmental characteristics

Epitestosterone is the 17α-epimer of testosterone and has been described as an anti-androgen, since it inhibits the effects produced by testosterone and dihydrotestosterone via the nuclear androgen receptor (nAR). However, epitestosterone also displays an effect which is similar to the non-classical effect of testosterone, depolarizing the membrane potential of Sertoli cells and inducing a rapid Ca²⁺ uptake. This study aimed to investigate the effects of a treatment with epitestosterone on developmental parameters of immature rats. Animals were chemically castrated by using the gonadotropin-releasing hormone (GnRH) antagonist cetrorelix and then received a replacement of 7 days with epitestosterone or testosterone. Replacement with either epitestosterone or testosterone restored the anogenital distance (AGD) and testicular weight which had been reduced by chemical castration. The immunocontent of nAR and the nAR-immunoreactivity were reduced by epitestosterone treatment in the testis of both castrated and non-castrated animals. Furthermore, testosterone was unable of changing the membrane potential of Sertoli cells through its non-classical action in the group of animals castrated and replaced with epitestosterone. In conclusion, in relation to the level of protein expression of nAR epitestosterone acts as an anti-androgen. However, it acts in the same way as testosterone when genital development parameters are evaluated. Moreover, in castrated rats epitestosterone suppressed the non-classical response of testosterone, changing the pattern of testosterone signalling via a membrane mechanism in Sertoli cells.

Metabolic profiling of cholesterol and sex steroid hormones to monitor urological diseases

Cholesterol and sex steroid hormones including androgens and estrogens play a critical role in the development and progression of urological diseases such as prostate cancer. This disease remains the most commonly diagnosed malignant tumor in men and is the leading cause of death from different cancers. Attempts to understand the role of cholesterol and steroid metabolism in urological diseases have been ongoing for many years, but despite this, our mechanistic and translational understanding remains elusive. In order to further evaluate the problem, we have taken an interest in metabolomics; a discipline dedicated to the systematic study of biologically active metabolites in cells, tissues, hair and biofluids. Recently, we provided evidence that a quantitative measurement of cholesterol and sex steroid metabolites can be successfully achieved using hair of human and mouse models. The overall goal of this short review article is to introduce current metabolomic technologies for the quantitative biomarker assay development and also to provide new insight into understanding the underlying mechanisms that trigger the pathological condition. Furthermore, this review will place a particular emphasis on how to prepare biospecimens (e.g., hair fiber), quantify molecular profiles and assess their clinical significance in various urological diseases.

Liquid Chromatography-Mass Spectrometry-Based In Vitro Metabolic Profiling Reveals Altered Enzyme Expressions in Eicosanoid Metabolism

Background

Eicosanoids are metabolites of arachidonic acid that are rapidly biosynthesized and degraded during inflammation, and their metabolic changes reveal altered enzyme expression following drug treatment. We developed an eicosanoid profiling method and evaluated their changes on drug treatment.

Methods

Simultaneous quantitative profiling of 32 eicosanoids in liver S9 fractions obtained from rabbits with carrageenan-induced inflammation was performed and validated by liquid chromatography-mass spectrometry coupled to anion-exchange solid-phase purification.

Results

The limit of quantification for the devised method ranged from 0.5 to 20.0 ng/mg protein, and calibration linearity was achieved (R²>0.99). The precision (% CV) and accuracy (% bias) ranged from 4.7 to 10.3% and 88.4 to 110.9%, respectively, and overall recoveries ranged from 58.0 to 105.3%. Our method was then applied and showed that epitestosterone treatment reduced the levels of all eicosanoids that were generated by cyclooxygenases and lipoxygenases.

Conclusions

Quantitative eicosanoid profiling combined with in vitro metabolic assays may be useful for evaluating metabolic changes affected by drugs during eicosanoid metabolism.

Bringing GC-MS profiling of steroids into clinical applications

Abnormalities of steroid biosynthesis and excretion are responsible for the development and prevention of endocrine disorders, such as metabolic syndromes, cancers, and neurodegenerative diseases. Due to their biochemical roles in endocrine system, qualitative and quantitative analysis of steroid hormones in various biological specimens is needed to elucidate their altered expression. Mass spectrometry (MS)-based steroid profiling can reveal the states of metabolites in biological systems and provide comprehensive insights by allowing comparisons between metabolites present in cells, tissues, or organisms. In addition, the activities of many enzymes related to steroid metabolism often lead to hormonal imbalances that have serious consequences, and which are responsible for the progress of hormone-dependent diseases. In contrast to immunoaffinity-based enzyme assays, MS-based methods are more reproducible in quantification. In particular, high-resolution gas chromatographic (GC) separation of steroids with similar chemical structures can be achieved to provide rapid and reproducible results with excellent purification. GC-MS profiling therefore has been widely used for steroid analysis, and offers the basis for techniques that can be applied to large-scale clinical studies. Recent advances in analytical technologies combined with inter-disciplinary strategies, such as physiology and bioinformatics, will help in understanding the biochemical roles of steroid hormones. Therefore, comprehensive analytical protocols in steroid analysis for different research purposes may contribute to the elucidation of complex metabolic processes relevant to steroid function in many endocrine disorders, and in the identification of diagnostic biomarkers.

Clinical biochemistry of dihydrotestosterone

Dihydrotestosterone (DHT) is the most potent natural androgen in humans. There has been an increasing interest in this androgen and its role in the development of primary and secondary sexual characteristics as well as its potential roles in diseases ranging from prostate and breast cancer to Alzheimer's disease. Despite the range of pathologies shown to involve DHT there is little evidence for measurement of serum DHT in the management of these diseases. In this review we describe the physiology of DHT production and action, summarize current concepts in the role of DHT in the pathogenesis of various disorders of sexual development, compare current methods for the measurement of DHT and conclude on the clinical utility of DHT measurement. The clinical indications for the measurement of DHT in serum are: investigation of 5α reductase deficiency in infants with ambiguous genitalia and palpable gonads; men with delayed puberty and/or undescended testes; and to confirm the presence of active testicular tissue. Investigation is aided by the use of human chorionic gonadotrophin stimulation. Due to paucity of published data on this procedure, it is important to follow guidelines prescribed by the laboratory performing the analysis to ensure accurate interpretation.

Gas chromatography/mass spectrometry based hair steroid profiling may reveal pathogenesis in hair follicles of the scalp

A method of steroid profiling, including androgens, progestins, corticoids and sterols, was developed to evaluate the concentrations of steroids as well as the activities of the enzymes responsible for steroidogenesis in hair by gas chromatography/mass spectrometry. The extraction efficiencies of steroids from the hair matrix were improved by ultrasonication for 1 h at 50 °C. The overall recoveries ranged from 71 to 132%, with a limit of quantification for all analytes ranging from 1 to 50 ng/g. The devised method was used to identify the metabolic changes for both male-pattern baldness (MPB) and the drug efficiency of dutasteride, which inhibits 5α-reductase. Increased dihydrotestosterone levels and the dihydrotestosterone/testosterone (DHT/T) ratio, which is responsible for the 5α-reductase activity, were observed in the MPB patients. A dutasteride treatment resulted in decreases in the DHT and 5α-androstanedione concentrations and DHT/T ratio in the hair samples. Hair steroid profiling reflects the sebaceous status in the scalp and may be useful for monitoring the metabolic responses to both the disease and drug actions.

Male pattern baldness and prostate cancer risk in a population-based case-control study

PURPOSE

Male pattern baldness (MPB) and prostate cancer (PCa) share commonality as prevalent, heritable and androgen-related conditions. Studies exploring the relationship between the two conditions have been inconclusive. Using a population-based, case-control study of PCa, we explore the relationship between early-onset MPB and PCa risk.

METHODS

Cases were men aged 35-74 diagnosed with PCa between 2002 and 2005 in King County, Washington. Controls were frequency matched by age and identified by random digit dialing. Hair pattern at age 30 and at 1 year prior to diagnosis (cases) or reference date (controls) was determined using showcards. PCa risk associated with balding was assessed with logistic regression.

RESULTS

Data from 999 cases of PCa and 942 controls were analyzed. Hair loss at age 30 was more common in controls (25.2%) than cases (19.8%, p=0.005), and those with hair loss at age 30 had a 29% relative risk reduction for PCa (OR 0.71, 95% CI 0.56-0.91). No risk reduction was seen for men only reporting hair loss at referent age (OR 0.90, 95% CI 0.73-1.12). In men aged >60 at referent date, the risk reduction was greater for men with hair loss at age 30 from both the top of head and forehead (OR 0.55, 95% CI 0.33-0.93).

CONCLUSION

Early-onset MPB was associated with a reduced relative risk of PCa in this population-based study. Further research into a possible mechanistic link between these prevalent and androgen-related conditions is warranted.

Heat-map visualization of gas chromatography-mass spectrometry based quantitative signatures on steroid metabolism

Abnormalities in steroid hormones are responsible for the development and prevention of endocrine diseases. Due to their biochemical roles in endocrine system, the quantitative evaluation of steroid hormones is needed to elucidate altered expression of steroids. Gas chromatographic-mass spectrometric (GC-MS) profiling of 70 urinary steroids, containing 22 androgens, 18 estrogens, 15 corticoids, 13 progestins, and 2 sterols, were validated and its quantitative data were visualized using hierarchically clustered heat maps to allow "steroid signatures". The devised method provided a good linearity (r(2) > 0.994) with the exception of cholesterol (r(2) = 0.983). Precisions (% CV) and accuracies (% bias) ranged from 0.9% to 11.2% and from 92% to 119%, respectively, for most steroids tested. To evaluate metabolic changes, this method was applied to urine samples obtained from 59 patients with benign prostatic hyperplasia (BPH) versus 41 healthy male subjects. Altered concentrations of urinary steroids found and heat maps produced during this 70-compound study showed also differences between the ratios of steroid precursors and their metabolites (representing enzyme activity). Heat maps showed that oxidoreductases clustered (5alpha-reductase, 3alpha-HSD, 3beta-HSD, and 17beta-HSD, except for 20alpha-HSD). These results support that data transformation is valid, since 5alpha-reductase is a marker of BPH and 17beta-HSD is positively expressed in prostate cells. Multitargeted profiling analysis of steroids generated quantitative results that help to explain correlations between enzyme activities. The data transformation and visualization described may to be found in the integration with the mining biomarkers of hormone-dependent diseases.

Metabolomics, a New Promising Technology for Toxicological Research

Metabolomics which deals with the biological metabolite profile produced in the body and its relation to disease state is a relatively recent research area for drug discovery and biological sciences including toxicology and pharmacology. Metabolomics, based on analytical method and multivariate analysis, has been considered a promising technology because of its advantage over other toxicogenomic and toxicoproteomic approaches. The application of metabolomics includes the development of biomarkers associated with the pathogenesis of various diseases, alternative toxicity tests, high-throughput screening (HTS), and risk assessment, allowing the simultaneous acquisition of multiple biochemical parameters in biological samples. The metabolic profile of urine, in particular, often shows changes in response to exposure to xenobiotics or disease-induced stress, because of the biological system's attempt to maintain homeostasis. In this review, we focus on the most recent advances and applications of metabolomics in toxicological research.

Genetic aspects of epitestosterone formation and androgen disposition: influence of polymorphisms in CYP17 and UGT2B enzymes

OBJECTIVE

Testosterone is a commonly abused androgen in sports and in the gym culture of the society. Its abuse is conventionally disclosed by urinary assay of the testosterone/epitestosterone (T/E) glucuronide ratio, which should not exceed 4. A noteworthy number of athletes, however, have higher natural ratios than 4, most likely because of decreased excretion of epitestosterone glucuronide. Falsely positive doping test results are of great concern for the legal rights of the sportsman. Our objective was to study the genetic aspects of epitestosterone formation, and to elucidate the impact of genetic variation in androgen-metabolizing enzymes.

METHODS

Urine from different study populations was analysed for androgen glucuronides by gas chromatography-mass spectrometry. All men were genotyped for the uridine diphospho-glucuronosyltransferase (UGT) 2B17 deletion polymorphism and single nucleotide polymorphisms in the cytochrome P-450c17alpha (CYP17), UGT2B15 and UGT2B7 genes. Expression of UGT2B15 mRNA in human liver samples was analysed using real-time PCR.

RESULTS

A T>C (A1>A2) promoter polymorphism in the CYP17 gene was associated with the urinary glucuronide levels of epitestosterone and its putative precursor androstene-3beta, 17alpha-diol, resulting in 64% higher T/E ratios in A1/A1 homozygotes. Individuals devoid of UGT2B17 had significantly higher UGT2B15 mRNA levels in liver than individuals carrying two functional UGT2B17 alleles.

CONCLUSION

The CYP17 promoter polymorphism may partly explain high natural (>4) T/E ratios. Our data indicate that 5-androstene-3beta, 17alpha-diol is an important precursor of epitestosterone and that CYP17 is involved in its production. In addition, we found that lack of the UGT2B17 enzyme may be compensated for by increase in UGT2B15 transcription.

Determination of cholesterol in human hair using gas chromatography-mass spectrometry

This work describes a sensitive method for determining cholesterol in human hair using GC-MS. In this study, we used a very small amount of hair, only 1 mg, to quantify cholesterol. We also can achieve more effective purification and a good recovery over 92% with solid-phase extraction using an Oasis HLB cartridge. The intra-day and inter-day precision and accuracy values were less than 7.08%. Cholesterol was determined to be in the range of 355-1693 microg/g in healthy human hair. We tested the concentration correlation between the serum and hair to examine the feasibility of using the hair cholesterol level as an index of the serum cholesterol level. The correlation between the serum cholesterol was 0.86 (r-value) in patients with hypercholesterolemia. This finding indicates that, in the clinical field, hair could replace serum in cholesterol level measurement.

Evaluation of androgens in the scalp hair and plasma of patients with male-pattern baldness before and after finasteride administration

BACKGROUND

Finasteride, a competitive inhibitor of the enzyme 5alpha-reductase II, is widely used as a medical treatment for patients with male-pattern baldness (MPB), which is affected by the distribution of androgenic steroids. It is also notable that the androgenic effect in MPB is different for each region of the head.

OBJECTIVES

To study the effect of the drug finasteride, we quantified androgenic steroids in the vertex and occipital scalp hair and in the plasma of patients with MPB.

METHODS

The patients with MPB, aged 23-52 years, were treated with finasteride 1 mg daily for 5 months. The hair and plasma samples were hydrolysed, extracted with n-pentane, and derivatized with MSTFA:NH4I:DTE (1000:4:5, v/w/w). We analysed the concentrations of dihydrotestosterone (DHT) and testosterone (T) in the hair and plasma using gas chromatography-mass spectrometry (GC-MS).

RESULTS

In the hair, the ratio of DHT/T was decreased in the vertex scalp hair after the individual received finasteride (P < 0.005). However, we found no significant difference in the ratio of DHT/T in the occipital scalp hair before and after individuals received finasteride. Like the results in the vertex scalp hair, the ratio of DHT/T in the plasma was remarkably decreased after finasteride administration (P < 0.001).

CONCLUSIONS

This study supports the effect of finasteride in patients with MPB by examining the decreased level of DHT/T in scalp hair and in plasma. Thus, in view of the androgenic effect in the different hair regions, the vertex scalp hair plays a more important role for patients with MPB treated with finasteride than does the occipital hair.

Comparative studies on level of androgens in hair and plasma with premature male-pattern baldness

BACKGROUND

It is well known that male-pattern baldness (MPB) is not started from occipital, but frontal or scalp of head. We can assume that distribution of androgenic steroids is different for each region of the head.

OBJECTIVE

We hypothesize that the levels of androgenic steroids are different not only between vertex hair with MPB and controls but also between occipital hair with MPB and controls. Moreover, we want to search for the biochemical indicator in plasma and hair sample (baldness: 22, non-baldness: 13) obtained from dermatology of medical center. After then, we desire to present fundamental data regarding diagnosis, medical cure, and prevention for premature MPB.

METHODS

After hair and plasma were hydrolyzed, and then extracted with organic solvent. To assess androgenic steroids levels, we used gas chromatography-mass spectrometry (GC-MS) system in selected ion monitoring mode.

RESULTS

The level of dihydrotestosterone (DHT) and the ratio of testosterone to epitestosterone (T/E ratio) in vertex hair from premature baldness subjects were higher than in the sample of non-baldness subjects (P<0.001, 0.001), whereas the levels of androgens in occipital hair from the same baldness group were not different. In addition, we discovered the levels of DHT, testosterone, and DHT/T ratio in plasma from premature MPB were higher than in those of control subjects (P<0.001, 0.001, 0.005).

CONCLUSION

We verified that the distribution of androgenic steroids is unlike in various regions of individual subjects. Moreover, the increased DHT/T ratio in balding plasma indirectly confirms the high activity of 5alpha-reductase type II.

The nail and hair in forensic science

Drugs, chemicals, and biological substances accumulate and are stored in hair and nails where they can be detected and measured. Advantages of analyzing hair and nail samples also include their easy and non-invasive collection, the small sample size required for analysis, and their easy storage at room temperature. We report 3 examples of heavy metal poisoning diagnosed because of the hair or nail symptoms. Drugs and toxins that can be detected in hair and nails are reviewed and the application of hair/nail analysis in general and in forensic medicine is discussed.

Darwinian aesthetics: sexual selection and the biology of beauty

Current theoretical and empirical findings suggest that mate preferences are mainly cued on visual, vocal and chemical cues that reveal health including developmental health. Beautiful and irresistible features have evolved numerous times in plants and animals due to sexual selection, and such preferences and beauty standards provide evidence for the claim that human beauty and obsession with bodily beauty are mirrored in analogous traits and tendencies throughout the plant and animal kingdoms. Human beauty standards reflect our evolutionary distant and recent past and emphasize the role of health assessment in mate choice as reflected by analyses of the attractiveness of visual characters of the face and the body, but also of vocal and olfactory signals. Although beauty standards may vary between cultures and between times, we show in this review that the underlying selection pressures, which shaped the standards, are the same. Moreover we show that it is not the content of the standards that show evidence of convergence--it is the rules or how we construct beauty ideals that have universalities across cultures. These findings have implications for medical, social and biological sciences.

Epitestosterone

Epitestosterone has been identified as a natural component of biological fluids of several mammals including man. For a long time it was believed that it is a metabolite without any hormonal activity and without any marked relationship to the hormonal state in health and disease. Neither the biosynthetic pathway nor the site of its formation in man have been unequivocally confirmed to date. It apparently parallels the formation of testosterone (T), but on the other hand its concentration is not influenced by exogenous administration of testosterone. This fact creates the basis of the present doping control of testosterone abuse. In 1989 an observation was presented in a dermatological study that epitestosterone exerts an effect counteracting the action of testosterone on flank organ of Syrian hamster. Further studies showed that a complex action consisting of competitive binding of epitestosterone to androgen receptor, of inhibition of testosterone biosynthesis and its reduction to dihydrotestosterone and of antigonadotropic activity could be demonstrated in rat, mice and human tissues. It can be presumed that epitestosterone as a natural hormone can contribute to the regulation of such androgen dependent events as, e.g. the control of prostate growth or body hair distribution.

Measurement of corticoids in the patients with clinical features indicative of mineralocorticoid excess

BACKGROUND

A method for the measurement of five important serum and urinary corticoids on the syndrome of mineralcorticoid excess is reported. The methodology was combined gas chromatography-mass spectrometry (GC-MS) with selected ion-monitoring mode.

METHODS

After extraction with a solid-phase cartridge using an Oasis HLB copolymer, the residues were derivatized with a mixture of N-methyl-N-trimethylsilyltrifluoroacetamide/ammonium iodide/dithioerythritol (1000:4:5, v/w/w), and analyzed.

RESULTS

The linearity as the regression coefficients were >0.979 over a range of 1-500 ng/ml, and limit of detection ranged from 1 to 3 ng/ml while their analytical recoveries varied in the range of 75.7-94.9%. The overall precision (% CV) of the method were 3.2-7.2% and 3.6-6.3% for serum and urine, respectively. The accuracy expresses as % bias ranged from -4.1 to 6.4%. This assay was used on two patients with hypokalemic hypertension, and may be useful in ruling out mineralcorticoid excess (AME) type 1 or 2.

CONCLUSIONS

The present GC-MS technique may be useful to differentiate between the syndrome of AME and other hypertensive diseases with clinical features suggestive of mineralcorticoid excess because of the assay's reliablity and precision.

Sex- and age-related changes in epitestosterone in relation to pregnenolone sulfate and testosterone in normal subjects

Epitestosterone has been demonstrated to act at various levels as a weak antiandrogen. So far, its serum levels have been followed up only in males. Epitestosterone and its major circulating precursor pregnenolone sulfate and T were measured in serum from 211 healthy women and 386 men to find out whether serum concentrations of epitestosterone are sufficient to exert its antiandrogenic actions. In women, epitestosterone exhibited a maximum around 20 yr of age, followed by a continuous decline up to menopause and by a further increase in the postmenopause. In men, maximum epitestosterone levels were detected at around 35 yr of age, followed by a continuous decrease. Pregnenolone sulfate levels in women reached their maximum at about age 32 yr and then declined continuously, and in males the maximum was reached about 5 yr earlier and then remained nearly constant. Epitestosterone correlated with pregnenolone sulfate only in males. In both sexes a sharp decrease of the epitestosterone/T ratio around puberty occurred. In conclusion, concentrations of epitestosterone and pregnenolone sulfate are age dependent and, at least in prepubertal boys and girls, epitestosterone reaches or even exceeds the concentrations of T, thus supporting its role as an endogenous antiandrogen. The dissimilarities in the course of epitestosterone levels through the lifespan of men and women and its relation to pregnenolone sulfate concentrations raise the question of the contribution of the adrenals and gonads to the production of both steroids and even to the uniformity of the mechanism of epitestosterone formation.

Determination of non-steroidal estrogens in breast milk, plasma, urine and hair by gas chromatography/mass spectrometry

It is suspected that all the natural estrogens occurring in the human body, as well as dietary and synthetic estrogens, diversely affect the endocrine system depending on their exposure patterns. More rapid, reliable and accurate measurements of these compounds in various biological matrices are thus becoming an important task. After solid-phase extraction using an Oasis HLB extraction cartridge, the estrogen concentrates were derivatized with a mixture of N-methyl-N-trifluorotrimethylsilylacetamide/ammonium iodide/dithioerythritol (1000:4:5, v/w/w) for analysis by gas chromatography/mass spectrometry in the selected ion-monitoring (SIM) mode. The qualitative identification of estrogens detected in SIM mode was further confirmed by tandem mass spectrometry using low-energy collision-induced dissociation (CID) mode. The method for the assay of the 20 estrogens was linear over the ranges of 1-1000 micro g/L for biological fluids and 1-200 micro g/kg for hair with high correlation coefficient (>0.99). The limits of quantitation (LOQ) ranged from 1.0-10 micro g/L (or micro g/kg) and the limit of detection ranged from 0.2-3 micro g/L (or micro g/kg). The average precision (% CV) and accuracy (% bias) of the method determined at the LOQ, low, and medium concentrations were in the ranges 2.6-9.2 and -4.1-7.7, respectively. The average extraction recovery of the estrogens from plasma and hair at the three concentration levels varied in the ranges 77-103% (1.9-14.3% CV) and 73-104% (3.1-14%), respectively. The distribution patterns of the estrogens were characteristic of each biosample. Five estrogens in the range 1.5-44.9 micro g/L were measured in breast milk, 8 estrogens in the range 3.5-322 micro g/L in plasma, 12 estrogens at 1.2-442 micro g/L in urine, and biochanin-A at 13.2-39.1 micro g/kg in hair. Because of its high sensitivity, good precision and specificity, the present method was found suitable for the trace analysis of dietary and synthetic estrogens in complex biosamples such as breast milk, plasma, urine and hair.

Measurement of testosterone and pregnenolone in nails using gas chromatography-mass spectrometry

An efficient method for the determination of testosterone and pregnenolone in human nails using gas chromatography-mass spectrometry (GC-MS) with d3-testosterone as an internal standard is described. The method involves alkaline digestion and liquid-liquid extraction, with subsequent conversion to mixed pentafluoropenyldimethylsilyl-trimethylsilyl (flophemesyl-TMS) derivatives for sensitive analysis in the selected-ion monitoring (SIM) mode. The limit of detection (LOD) and limit of quantification (LOQ) were lowered to 0.1 and 0.2 pg/g, respectively, when 100 mg of nail-clippings were used. The mean recoveries of testosterone and pregnenolone were 89.8 and 86.7%, respectively, while good overall precision (% C.V.; 4.5-9.5) and accuracy (% bias; 3.9-8.4) were demonstrated. Linearity as a correlation coefficient was 0.9913 (testosterone) and 0.9965 (pregnenolone). When applied to fingernail and toenail samples from seven healthy men and nine healthy women, testosterone and pregnenolone were positively detected in the concentration range of 0.24-5.80 ng/g. The levels of two steroids studied in the nails were found to be higher in the male subjects than in the female subjects, and except for the toenails of the females, the levels of testosterone were higher than those of pregnenolone.