Metabolomic Approach To Evaluate the Toxicological Effects of Nonylphenol with Rat Urine

Metabolomics has focused on toxicological applications to (1) understand the mechanisms of toxicity, (2) identify novel biomarkers of toxicity, and (3) provide in vivo assessment in animal models through simple and fast methods to date. The toxicological effects of nonylphenol (NP) were evaluated after intraperitoneal injection of rats with 0, 50, and 250 mg kg(-1) day(-1) NP for four consecutive days. In the nontargeted approach, different extraction conditions were introduced to investigate the effects of NP on rats through gas chromatography/mass spectrometry (GC/MS). The GC/MS data obtained were further analyzed with partial least-squares discriminant analysis to compare toxicological effects between control and treated groups. The targeted approach was also used in combination with GC/MS to quantify endocrine hormones and to identify possible biomarkers in rat urine under optimal extraction conditions. In addition, we considered the metabolic trajectory to examine the metabolite profiles and patterns related to steroid metabolism in rats that were treated with NP, considering both treatment amount and time. The data suggest that tetrahydrocorticosterone and 5alpha-tetrahydrocorticosterone are possible urinary biomarkers of NP-induced toxicity. This metabolomic approach is a promising tool to assist with screening in toxicological studies.

Survival change of ventral mesencephalon-derived progenitor cells after grafting into unilateral intact adult rat striatum

Neural transplantation is one of the most promising treatments for neurodegenerative disorders. Survival rates of embryonic dopamine (DA) neurons following transplantation are low, between 2% and 20% in a number of animal models. To further establish survival changes of the transplanted gestational day 13.5 ventral mesencephalic (VM) cells into left intact adult rat striata so that design strategies of increasing survival of DA neurons, the tyrosine hydroxylase (TH) expression of VM-derived progenitor cells has been examined using immunohistochemistry and Western blot analysis. TH immunostaining revealed that the grafted VM cells developed to mature TH-positive neurons strongly at 3 weeks, peaked at 4 weeks, thereafter, gradually dropped following the degenerative expression of the grafted cells at both 5 and 6 weeks after transplantation. Western blot analysis also showed that the TH proteins were maximally expressed at 4 weeks post-grafting. Our finding suggested that the peak of surviving VM-derived TH positive cells occurred approximately 4 weeks after transplantation.

Rapid column-switching liquid chromatography/mass spectrometric assay for DHEA-sulfate in the plasma of patients with Alzheimer's disease

A simple and highly sensitive method for the quantification of dehydroepiandrosterone-3-sulfate (DHEAS) in human plasma was developed. DHEAS was directly determined in plasma using column-switching liquid chromatography/mass spectrometry (LC-MS). The plasma was filtered with a membrane filter. The filtrate was injected onto a pre-column without further sample preparation such as extraction or derivatization. The pre-column was washed with an aqueous solution to remove interference and the analyte was eluted into a reversed-phase C(18) analytical column for separation and detection using a column-switching valve. The calibration range of DHEAS was 0.01-10 micromol/L, and the linearity of the method was 0.999. The limit of detection (LOD) at a signal-to-noise (S/N) ratio of 3 was 5 nmol/L. The accuracy and precision (%CV) were less than 10% in within-day and day-to-day variations. To explore the relationship between Alzheimer's disease and the DHEAS level in human plasma, the concentrations of DHEAS in female patients with Alzheimer's disease (n = 20) and in normal female subjects (n = 20) were measured. The level of DHEAS was significantly decreased in the plasma of patients with Alzheimer's disease (p < 0.0002) compared with that in normal subjects. From the results, we concluded that our method is sufficiently sensitivity and reliability for the quantification of DHEAS in clinical samples. Plasma DHEAS concentration could be an important marker to understand the pathogenesis of Alzheimer's disease.

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.

Increased urinary level of oxidized nucleosides in patients with mild-to-moderate Alzheimer's disease

OBJECTIVE

Oxidative stress may play an important role in the pathogenesis of Alzheimer's disease (AD).

DESIGN AND METHODS

To investigate the possible role of oxidative DNA damage in the pathogenesis of AD, we measured the metabolite concentrations of oxidized nucleosides (pseudouridine, 1-methyladenosine, 5-methylcytidine, 5-methyl-2'-deoxycytidine, 3-methyluridine, N(2), N(2)-dimethylguanosine, 8-hydroxy-2'-deoxyguanosine, 5-deoxyadenosine and 2-deoxyguanosine) in urine between AD (n=36) and control subjects (n=34) using liquid chromatography-mass spectrometry (LC-MS) without urine preparation.

RESULTS

In AD, the 3-methyluridine, 1-methyladenosine, 8-hydroxy-2'-deoxyguanosine (p<0.05, respectively), 2-deoxyguanosine (p<0.01) and pseudouridine, N(2), N(2)-dimethylguanosine (p<0.001, respectively) were significantly increased when compared with the control subjects.

CONCLUSION

The results indicate that oxidized urinary nucleosides may be useful as biomarkers for AD in early stages.

Prenatal GABAB1 and GABAB2 receptors: cellular and subcellular organelle localization in early fetal rat cortical neurons

Gamma-aminobutyric acid (GABA)(B) receptors appear to influence developmental events, depending on whether they are found at a synapse or in extrasynaptic areas. Little, if anything, is known as to the cellular and subcellular localization of GABA(B1) and GABA(B2) receptors during early fetal development. We used Western blots, immunohistochemistry, and postembedding immunoelectronmicroscopy to investigate fetal rat brain expression and distribution of these receptor proteins. GABA(B1) is expressed as early as gestational day (GD) 11.5 and 12.5, with immunoreactivity found in the all neuroepithelium, and a high expression in the mantel zone and the cortical area's plate; no immunolabeling for GABA(B2) receptor was observed. Our immunogold studies define a pattern of early GABA(B1) receptor protein in dendrite processes, endoplasmic reticulum, and axon terminals of the cortical neuroepithelium on GD 11.5. On GD 12.5, GABA(B1) receptor immunogold was found in dendrite processes, spines and tree, axon terminals, mitochondria, and intracellular organelles of the cortical neuroepithelium. No synapse formation was apparent as no synaptophysin could be found on either GD 11.5 or 12.5. We suggest that GABA(B1) has a functional role in the early fetal brain during neuronal proliferation and migration, and that it is different from the established functional GABA(B) receptor.

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.

Influence of ginsenoside Rb1 on brain neurosteroid during acute immobilization stress

This study examined whether or not acute stress is linked to increases in the neurosteroid levels, which is a well-known neurotransmitters associated with stress stimuli. The ginsenoside, Rb1, was tested in order to better understand its potential effects on altering the neurosteroid levels and ultimately attenuating stress. The optimal stressed condition was checked by measuring the 5a-dihydroprogesterone (DHP) and allopregnanolone (THP) levels in the brain after immobilization stress at various times. Based on this result, an acute stress model was set up to give 30 min of immobilization stress. The DHP and THP brain levels of the stressed mice were then investigated after administering Rb1 orally (10 mg/kg). These results were compared with the neurosteroid level in the stressed mice not given Rbl. Saline was administered orally to the nonstressed mice to check the placebo effect. Acute immobilization stress induced an increase in the THP and DHP concentration in the frontal cortex and cerebellum. When Rb1 was administered orally prior to immobilization stress, the THP level in the frontal cortex and cerebellum was significantly lower than that in the stressed animals not given Rbl. On the other hand, the DHP level was lower in the cerebellum only. This suggests that the metabolism of the brain neurosteroids is linked to psychological stress, and Rb1 attenuates the stress-induced increase in neurosteroids.

Capillary electrophoretic competitive immunoassay with laser-induced fluorescence detection for methionine-enkephalin

Immunoassays are commonly used in bioresearch for the detection and quantification of small proteins and macromolecules in biological fluids and other complex matrices. In this report, a competitive immunoassay using capillary electrophoresis (CE) with laser-induced fluorescence was developed for methionine-enkephalin (ME). The method is based on the competitive reaction between the ME and fluorescein conjugated ME (ME-F) with anti-ME antibody, capillary electrophoresis separation of the ME-antibody bound and free ME-F, followed by the laser-induced fluorescence detection of the fluorescent species. With the optimized separation conditions, it was possible to separate the antibody bound and free fluorescien conjugated ME by a capillary electrophoresis-laser-induced fluorescence (CE-LIF) analysis using an uncoated fused-silica capillaries. The results concluded that the assay specificity, selectivity and accuracy were excellent.

The antistress effect of ginseng total saponin and ginsenoside Rg3 and Rb1 evaluated by brain polyamine level under immobilization stress

The present study aims to demonstrate the ability of ginseng total saponin (GTS), ginsenosides Rg3 and Rb1 to reduce brain polyamine levels in immobilization-stressed gerbil mice. A previous study reported that ginsenosides had an anti-stress property. So, we tested the anti-stress effect of ginseng by investigating the brain level of polyamine, a well-known stress stimuli marker. We determined the brain polyamine levels under 30-min immobilization stress in pretreating GTS (100 mgkg(-1), oral), ginsenosides Rg3 and Rb1 (10 mgkg(-1), oral, respectively). Then, we compared polyamine levels between the non-stressed mouse and the stressed mouse which had taken saline orally to check the placebo effect. Putrescine (PUT) levels were significantly increased (P < 0.01) in the stressed condition, but it was reduced in pretreatment of GTS, ginsenosides Rg3 (P < 0.01, respectively) and Rb1 (P < 0.001) under 30-min immobilization stressed-mouse. However, other polyamine levels did not change regardless of stressed condition or GTS-, ginsenosides Rg3- and Rb1-treated stressed condition. These results mean that only PUT could be a marker for stress and GTS, ginsenosides Rg3 and Rb1 administration lead to an anti-stress effect. Thus, our studies indicate that GTS, ginsenosides Rg3 and Rb1 may play a neuroprotective role in the immobilization-stressed brain.

Simultaneous measurement of urinary polyols using gas chromatography/mass spectrometry

In the present study, we simultaneously measured several polyols, such as adonitol, arabitol, dulcitol, glucose, myo-inositol, mannitol, sorbitol, and xylitol, in urine by gas chromatography/mass spectrometry-positive chemical ionization. We also examined possible relationship between the levels of these metabolites and age in normal individuals. In order to proceed to its quantification by GC/MS, 200 microL of a urine sample were diluted with 3 ml of distilled water, lyophilized, acetylated, and then analyzed them. Using this method, we were able to quantify as little as 0.5-1.0 ng/microL, and we made the calibration curves to be linear from 0.25 to 250 ng/microL (r(2)>0.991). Analytical recoveries were over 89.4%, and the inter-day and intra-day variability for accuracy and reproducibility was less than 20%. In the normal urine sample, the levels of polyols were gender-differentiated and age-related. This simple GC/MS method is sensitive and allows the measurement of wide ranges of polyols using small amounts of urine. We conclude that the quantitation of urinary polyols using GC/MS appears to be a clinically useful method for assessing polyol-pathway activity.

Direct determination of nucleosides in the urine of patients with breast cancer using column-switching liquid chromatography–tandem mass spectrometry

We developed an analytical method for a simple, sensitive and simultaneous determination of oxidized nucleosides in urine using column-switching liquid chromatography-electrospray/tandem mass spectrometry (LC-ESI/MS/MS). We connected two columns through a six-way switching valve and effectively separated nucleosides in the urine from the interference by column-switching liquid chromatography. We monitored separated nucleosides using positive ionization tandem mass spectrometry in selective reaction monitoring (SRM) mode. The calibration ranges of nucleosides were 0.2-100 nmol/mL. The linearity of the method was 0.994-0.999, and the limits-of-detection (LOD) at a signal-to-noise (S/N) ratio of 3 were 0.1-0.2 nmol/mL. The coefficients of variation were in the range 2.28-11.74% for within-day variation and 4.36-11.15% for day-to-day variation, respectively. To explore the relationship between breast cancer and the nucleosides level in human urine, we measured the concentrations of nucleosides in female patients with breast cancer (n = 30) and in normal female subjects (n = 30). The concentration of nucleosides was significantly increased in patients with breast cancer when compared with the normal controls (1-methyladenosine; p < 0.005, N(2),N(2)-dimethylguanosine; p < 0.01, 5-hydroxymethyl-2'-deoxyuridine; p < 0.001, 8-hydroxy-2-deoxyguanosine; p < 0.001). Therefore, the elevated levels of nucleosides could be used as an important biomarker for breast-cancer research.

Direct determination of acylcarnitines in amniotic fluid by column-switching liquid chromatography with electrospray tandem mass spectrometry

A direct, simple, and simultaneous determination of acylcarnitines in amniotic fluid was developed using column-switching liquid chromatography/tandem mass spectrometry (LC/MS/MS). The analytes can be assayed within 20 min without any sample preparation process, and we monitored separated acylcarnitines with positive electrospray ionization (ESI)-MS/MS. The calibration ranges of acylcarnitines were 1 to 100 nmol/L. The linearity of the method was 0.992 to 0.999, and the limits of detection at a signal-to-noise ratio of 3 were 1 nmol/L. The coefficients of variation were in the range of 5.2 to 13.3% for within-day variation and 6.7 to 11.9% for day-to-day, respectively. We detected acylcarnitines in the amniotic fluid of 22 women in the early stages of their pregnancies in the range of 2.2 to 17.2 nmol/L. The proposed method could be applied to diagnosis, monitoring, and biomedical investigations of inborn errors of the organic acid and fatty acid metabolism of the embryo.

Ethanol modulates GABA(B) receptor expression in cortex and hippocampus of the adult rat brain

Using in situ hybridization, RNase protection assay and Western blot, we studied the effects of ethanol on the expression levels of GABA(B) receptor mRNA and protein in the cortex and hippocampus from adult rat brain. The results showed that ethanol significantly increased GABA(B1) and GABA(B2) receptor protein expression in the cortex, whereas only GABA(B2) was increased in the hippocampus. GABA(B) receptor agonist baclofen could partially reverse the effect of ethanol. Further studies of the mRNA levels defined that GABA(B1) mRNA levels were significantly increased in the hippocampus, with no significant changes of GABA(B2) mRNA levels. Moreover, GABA(B1) and GABA(B2) receptor mRNA levels were increased on 3-week ethanol treatment. Finally, GABA(B) agonist baclofen and antagonist phaclofen showed significant decreasing effects on GABA(B1) receptor mRNA levels in the cortex, but not in the hippocampus. These results were further confirmed by in situ hybridization. Thus, the present results showed the effects of ethanol on GABA(B) receptors in the cortex and hippocampus, implying the possible role of GABA(B) receptor in ethanol effects. The effects of GABA(B) receptor agonist and antagonist suggested that the possible mechanisms underlying that GABA(B) receptor modulated the behavioral effect induced by ethanol.

Micellar Phytosterols Effectively Reduce Cholesterol Absorption at Low Doses

BACKGROUND

The objective of this study was to evaluate the effects of micellar phytosterols on cholesterol absorption in humans.

METHODS

24 healthy adults (mean age 37 years, 16 women and 8 men) underwent four cholesterol-absorption tests to compare the effects of micellar phytosterols supplement containing 500, 300, 200 mg phytosterols and placebo on cholesterol absorption in a cross-over design. Individual absorption tests were separated by 2 weeks. Using the single oral isotope method, inhibition of cholesterol absorption was determined by gas-chromatography mass spectrometry measurement of the differences in plasma hexadeuterated cholesterol enrichment 4 days after test meals with or without phytosterols. Each test meal provided 500 kcal and 89 mg cholesterol including 40 mg tracer cholesterol. We used a general linear mixed model with SAS to test the significance of treatment effect.

RESULTS

Micellar phytosterols had a significant overall effect on cholesterol absorption (p = 0.0002), reduced cholesterol absorption by 23.3% at a dose of 300 mg phytosterols (p = 0.0004) and by 32.0% at a dose of 500 mg phytosterols (p = 0.0001) compared with the placebo. The effect of 200 mg treatment did not reach statistical significance but there was a tendency (p = 0.052).

CONCLUSION

Water-dispersible, micellar phytosterols reduced cholesterol absorption effectively at very low doses.

Simultaneous determination of cannabidiol, cannabinol, and \gD9-tetrahydrocannabinol in human hair by gas chromatography-mass spectrometryin human hair by gas chromatography-mass spectrometry

An analytical method was developed for evaluating the cannabidiol (CBD), cannabinol (CBN), and delta9-tetrahydrocannabinol (delta9-THC) level in human hair using gas chromatography-mass spectrometry (GC-MS). Hair samples (50 mg) were washed with isopropyl alcohol and cut into small fragments (< 1 mm). After adding a deuterated internal standard, the hair samples were incubated in 1.0 M NaOH for 10 min at 95 degrees C. The analytes from the resulting hydrolyzed samples were extracted using a mixture of n-hexane-ethyl acetate (75:25, v/v). The extracts were then evaporated, derivatized, and injected into the GC-MS. The recovery ranges of CBD, CBN, and delta9-THC at three concentration levels were 37.9-94.5% with good correlation coefficients (r2 >0.9989). The intra-day precision and accuracy ranged from -9.4% to 17.7%, and the inter-day precision and accuracy ranged from -15.5% to 14.5%, respectively. The limits of detection (LOD) for CBD, CBN, and delta9-THC were 0.005, 0.002, and 0.006 ng/mg, respectively. The applicability of this method of analyzing the hair samples from cannabis abusers was demonstrated.

Gas Chromatography-High-Resolution Mass Spectrometric Method for Determination of Methamphetamine and its Major Metabolite Amphetamine in Human Hair

Gas chromatography-high-resolution mass spectrometric (GC-HRMS) method is presented for the qualitative and quantitative analysis of methamphetamine (MA) and its major metabolite, amphetamine (AMP), in human hair. The method procedure involves decontamination of hair with distilled water and acetone, acidic hydrolysis and extraction in the presence of the internal standard, and GC-HRMS selective ion monitoring (SIM) analysis. The limits of detection (LOD) were 9 pg/mg for MA and 21 pg/mg for AMP using a 30-mg hair sample, and the SIM responses were linear with coefficients of correlation ranged from 0.9998 to 0.9999. The recoveries were found to be 91.1-92.3%. By using HRMS (resolution of 5000), detection sensitivity is improved because of the elimination of the biological background, and the LODs for MA and AMP were 2.4-4.4 times lower than those of low-resolution MS. The GC-HRMS method was successfully applied to the analysis of cosmetically treated hair, which is difficult to analyze with the conventional method.

Simultaneous determination of anabolic steroids and synthetic hormones in meat by freezing-lipid filtration, solid-phase extraction and gas chromatography–mass spectrometry

Estradiol, testosterone, progesterone, zeranol and diethylstilbestrol including estradiol metabolites were determined simultaneously in meat. Extraction of growth hormones was carried out by ultasonication using a methanol-water mixture. The growth hormones in the meat extract can be effectively separated from lipids by freezing-lipid filtration, followed by C8-solid phase extraction (SPE). During freezing-lipid filtration, about 90% of lipids are removed without any significant loss of growth hormones. For further clean-up, silica- and aminopropyl-SPE were used. To enhance detection sensitivity, the growth hormones are derivatized with trimethylsilyl reagents. Quantitation using isotope-labelled internal standards was performed by gas chromatography-mass spectrometry in the selected ion monitoring mode. The method detection limits were 0.1-0.4 microg/kg for all growth hormones. Overall recoveries of synthetic and natural growth hormones were 68-106% with coefficients of variation of 5-16% for the complete procedure.

Simultaneous determination of carisoprodol and meprobamate in human hair using solid-phase extraction and gas chromatography/mass spectrometry of the trimethylsilyl derivatives

Carisoprodol (CSP) is a musculoskeletal relaxant whose active metabolite is meprobamate (MPB). This drug has recently been noticed to be abused as an inexpensive alternative to illicit drugs in Korea. A method using solid-phase extraction (SPE) and gas chromatography/mass spectrometry (GC/MS) was developed for the determination of CSP and MPB in human hair. Hair samples (30 mg) were washed with distilled water and acetone, cut into small fragments (<1 mm), incubated in 1.0 M HCl overnight at 50 degrees C, and then adjusted to pH 6.5. The drugs were extracted from the resulting hydrolyzed solutions using a SPE column. The eluents were evaporated to dryness, then derivatized using N,O-bis(trimethylsilyl)trifluoroacetamide (BSTFA) with 1% trimethylchlorosilane (TMCS) at 120 degrees C for 30 min. The derivatized extract (1 microL) was injected into the GC/MS system. Recoveries were in the range of 91.5-93.1% for CSP and 85.5-93.0% for MPB. The linear ranges were 0.5-10.0 ng/mg for both CSP and MPB with good correlation coefficients (r(2) = 0.995). The intra-day precision and accuracy ranged from 1.5 to 9.3% and -17.5 to 3.6%, respectively, and the inter-day precision and accuracy ranged from 3.9 to 6.2% and -15.0 to -3.9%, respectively. The limits of detection for CSP and MPB were 0.13 and 0.12 ng/mg, respectively. The applicability of the method was proven by analyzing a hair sample from an authentic abuser.

Ethanol modulates the expression of GABAB receptor mRNAs in the prenatal rat brain in an age and area dependent manner

Prenatal ethanol exposure has various deleterious effects on neuronal development. As GABA(B) receptor is known to play an important role during the development of the CNS, we now focused on its mRNA expression pattern in the rat brain during the late gestational days (GD) from 15.5 to GD 21.5. Ethanol's effect was also observed from GD 11.5 to GD 21.5. GABA(B1) receptor mRNA showed a high expression level in GD 15.5 and 19.5, while GABA(B2) receptor mRNA did in GD 15.5 and 21.5. The mRNAs levels depended on age and area during development. Ethanol exposure decreased GABA(B1) receptor from GD 11.5 to GD 19.5 with slight increases in GD 21.5. The decreasing effects were area dependent, with the highest effects in the forebrain including cortex, whereas slight effects were observed in the midbrain and hindbrain. The present results suggest an important role of GABA(B) receptor in the effects of ethanol on prenatal brain developmental processes.

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.