12,519 research outputs found

    Contribution of the adrenal gland to the production of androstenedione and testosterone during the first two years of life

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    Androstenedione and testosterone were measured in whole adrenal glands of 56 previously healthy boys who died suddenly between birth and 2 yr of age. In each adrenal gland, the concentration of androstenedione considerably exceeded that of testosterone. The highest concentrations were found during the first week of life (median, 295 ng/g; range, 98- 320 ng/g). Thereafter, values decreased rapidly until the end of the first year of life (median, 10 ng/g; range, 4.4-22.7 ng/g). Adrenal testosterone concentrations averaged 15% of those of androstenedione in the same gland and similarly decreased until the end of the first year. The decrease of adrenal androgen concentrations paralleled the involution of the fetal adrenal zone. A close correlation existed between the concentration of androstenedione in adrenal tissue and plasma. However, no correlation existed between adrenal and plasma testosterone. When the adrenals and testes of the same infant were compared, there was 10 times more androstenedione in the adrenals than in the testes during the first 2 yr of life. The testes contained more testosterone than the adrenals only during the first 4 months. Thus, in infant boys the adrenals are the main source of androstenedione during the first 2 yr. After the sixth month of life, they also are the main source of testosterone

    TRPA1 mediates aromatase inhibitor-evoked pain by the aromatase substrate androstenedione

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    Aromatase inhibitors (AI) induce painful musculoskeletal symptoms (AIMSS), which are dependent upon the pain transducing receptor TRPA1. However, as the AI concentrations required to engage TRPA1 in mice are higher than those found in the plasma of patients, we hypothesized that additional factors may cooperate to induce AIMSS. Here we report that the aromatase substrate androstenedione, unique among several steroid hormones, targeted TRPA1 in peptidergic primary sensory neurons in rodent and human cells expressing the native or recombinant channel. Androstenedione dramatically lowered the concentration of letrozole required to engage TRPA1. Notably, addition of a minimal dose of androstenedione to physiologically ineffective doses of letrozole and oxidative stress byproducts produces AIMSS-like behaviors and neurogenic inflammatory responses in mice. Elevated androstenedione levels cooperated with low letrozole concentrations and inflammatory mediators were sufficient to provoke AIMSS-like behaviors. The generation of such painful conditions by small quantities of simultaneously administered TRPA1 agonists justifies previous failure to identify a precise link between AIs and AIMSS, underscoring the potential of channel antagonists to treat AIMSS

    Salivary testosterone measurement in women with and without polycystic ovary syndrome

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    Clinical and/or biochemical hyperandrogenism is one of the diagnostic criteria for PCOS. An evaluation of the role of salivary testosterone (salT) and androstenedione (salA) for the diagnosis of PCOS was undertaken in a cross sectional study involving 65 women without PCOS and 110 women with PCOS fulfilling all 3 diagnostic Rotterdam criteria. Serum and salivary androgen measurements were determined by LC-MS/MS. salT and salA were significantly elevated in PCOS compared to controls (P<001). No androgen marker was more predictive than another using ROC curves, but multiple logistic regression suggested salT was more predictive than free androgen index (FAI)(p<0.01). The combination of salT or FAI identified 100% of PCOS women. PCOS women with both biochemical and clinical hyperandrogenism as opposed to clinical hyperandrogenism alone showed a metabolic phenotype (p<0.05) and insulin resistance(p<0.001). PCOS patients with an isolated elevated FAI showed increased insulin resistance compared to those with an isolated salT(P<0.05). salT appeared to be at least as predictive as FAI for the diagnosis of the classical PCOS phenotype, and the combination of salT or FAI identified 100% of PCOS patients. This suggests that salT measurement by LC-MS/MS holds the promise of complementing existing laboratory tests as a means of assessing hyperandrogenemia

    Molecular genetics and pathophysiology of 17 beta-hydroxysteroid dehydrogenase 3 deficiency.

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    Autosomal recessive mutations in the 17 beta-hydroxysteroid dehydrogenase 3 gene impair the formation of testosterone in the fetal testis and give rise to genetic males with female external genitalia. Such individuals are usually raised as females, but virilize at the time of expected puberty as the result of increases in serum testosterone. Here we describe mutations in 12 additional subjects/families with this disorder. The 14 mutations characterized to date include 10 missense mutations, 3 splice junction abnormalities, and 1 small deletion that results in a frame shift. Three of these mutations have occurred in more than 1 family. Complementary DNAs incorporating 9 of the 10 missense mutations have been constructed and expressed in reporter cells; 8 of the 9 missense mutations cause almost complete loss of enzymatic activity. In 2 subjects with loss of function, missense mutations testosterone levels in testicular venous blood were very low. Considered together, these findings strongly suggest that the common mechanism for testosterone formation in postpubertal subjects with this disorder is the conversion of circulating androstenedione to testosterone by one or more of the unaffected 17 beta-hydroxysteroid dehydrogenase isoenzymes

    Testosterone and androstenedione concentrations in human testis and epididymis during the first two years of life

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    Testosterone and androstenedione were measured in testicular and epididymal tissue of 37 previously healthy infants between 1 and 24 months of age who died suddenly. In half of the patients elevated plasma levels of cortisol and androstenedione suggested preterminal stress. Plasma testosterone levels, however, did not differ from those in healthy infants. Testicular testosterone concentrations were maximal in boys from 1-3 months of age (median, 36.6 ng/g; range, 7-380 ng/g) with peak values similar to those found in pubertal or even adult testes. Thereafter testicular testosterone concentrations decreased and after the age of 6 months all values were below 12.5 ng/g, which corresponds to the low normal range of older prepubertal boys. Plasma testosterone and testicular testosterone correlated significantly (P less than 0.001). On average the testicular concentrations were 36.4 times higher than the corresponding plasma concentrations. Testicular androstenedione was low but correlated significantly with testicular testosterone (P less than 0.001). Epididymal testosterone concentrations were surprisingly high (1-3 months: median, 10.3 ng/g; range, 4-42.7 ng/g) and averaged 30% of the testicular testosterone concentration. Thus, epididymal testosterone concentrations were significantly higher than the circulating plasma testosterone levels, indicating the capacity of the infant epididymis to accumulate androgens. These findings suggest that high local testosterone concentrations during early infancy are important not only for the testis itself but particularly for the developing epididymi

    Androsterone glucuronide to dehydroepiandrosterone sulphate ratio is discriminatory for obese Caucasian women with polycystic ovary syndrome

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    BACKGROUND: Androsterone glucuronide (ADTG) concentrations have been suggested as a marker of the effects of androgens at the target tissue level. As the mechanism for hyperandrogenemia in obese and nonobese polycystic ovary syndrome (PCOS) may differ, this study compared the different androgen parameters in non-obese compared to obese women with PCOS, and in normal subjects. METHODS: Eleven non-obese and 14 obese women with PCOS were recruited and compared to 11 control women without PCOS. Total testosterone, dehydroepiandrosterone sulphate (DHEAS), ADTG, and androstenedione were analysed using gold standard tandem mass spectrometry, and the free androgen index (FAI) was calculated. RESULTS: Total testosterone, ADTG and androstendione levels did not differ between non-obese (body mass index (BMI) ≤25 kg/m2) and obese PCOS (BMI >25 kg/m2) but all were significantly higher than for controls (p < 0.01). The ADTG to DHEAS ratio was significantly elevated 39 ± 6 (p < 0.01) in obese PCOS in comparison to non-obese PCOS and controls (28 ± 5 and 29 ± 4, respectively). The free androgen index (FAI) and insulin resistance (HOMA-IR) were significantly higher in obese PCOS compared to non-obese PCOS and controls (p < 0.01). DHEAS was significantly higher in the non-obese versus obese PCOS (p < 0.01). All androgen parameters were significantly lower and sex hormone binding globulin (SHBG) significantly higher in normal subjects compared to those with obese and non-obese PCOS. CONCLUSIONS: The ADTG:DHEAS ratio was significantly elevated in obese PCOS compared to non-obese PCOS and controls suggesting that this may be a novel biomarker discriminatory for obese PCOS subjects, perhaps being driven by higher hepatic 5α reductase activity increasing ADTG formation in these women

    Biological variables in forager fertility performance: a critique of Bongaarts' model

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    African Studies Center Working Paper No. 60During the period of the 1960s and 1970s, a considerable amount of scholarly energy was devoted to studying the process of "modernization." Scholars, particularly political scientists and anthropologists, theorized extensively over exactly what modernization was and debated how it could best be quantified and measured.1 By the 1980s, however, the very notion of the "modern," along with its antithesis, the "traditional" was falling out of favor. Indeed, by declaring the new era "post-modern," the academic avant-guard signaled that the concept of modernity had effectively been relegated to the past. The past, however, is the turf of historians, so perhaps now that the concept of modernity has become old-fashioned it is time for historians to take their turn at examining its meaning. This paper will approach the concept of the "modern" by examining the role of advertising in creating notions of modernity in independence-era Ghana. Ghana, at the time of independence in 1957, was a country of supreme optimism about the future. Not only did Ghanaians see themselves as being on the cutting edge politically (as the first sub-Saharan colony to achieve independence), but they also believed that independence would bring a new era of economic development and wealth. Ghana, as a country, was "going places." The new nation's optimism found many manifestations, but this paper will focus on only one aspect of this exuberance—representations of transportation as modernity in the advertisements and articles of Ghana's premier newspaper, the Daily Graphic. As stated before, early scholarship on modernization was concerned primarily with developing a way of measuring the demise of the traditional and the rise of the modern. Such studies focused on examining populations of "traditional" or "transitional" peoples to attempt to discern just how "modern" they had or had not become. What the previous studies did not consider, and what this paper seeks to examine, is exactly how modernity was presented to and by such populations. No single factor seems to represent modernity more than motion itself—be it actual movement across space or be it social and economic change. Indeed, Daniel Lerner, the prominent scholar of modernity, defined the key aspect of being modern as having... [TRUNCATED

    Development and application of an UHPLC-MS/MS method for the simultaneous determination of 17 steroidal hormones in equine serum

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    A new, fast and simple analytical method that is able to identify and quantify simultaneously 17 steroid hormones and metabolites (Pregnenolone, 17-OH-Pregnenolone, Progesterone, 17-OH Progesterone, Androsterone, Androstenedione, DHEA, DHEAS, Testosterone, Cortisol, Corticosterone, Aldosterone, 11-Deoxycortisol, 11-Deoxycorticosterone, Dihydrotestosterone, Estrone, Estradiol) has been developed in equine serum using the UHPLC-MS/MS technique. 400 μL of sample were deproteinized with 1000 µl of acetonitrile, evaporated, restored with 50 µl of a solution of 25% methanol and injected in UHPLC-MS/MS triple quadrupole. The recovery percentage obtained by spiking the matrix at two different concentrations with a standard mixture of steroid hormones was in all cases higher than 85.60 % and with the percentage of coefficient of variation (CV) lower than 8.37%. The range of the correlation coefficients of the calibration curves of the analyzed compounds was 0.9922–0.9986, and the limits of detection (LODs) and limits of quantification (LOQs) were in the range of 0.002–2 ng ml-1 and 0.0055-5.5 ng ml-1, respectively. The detected LOQ for testosterone (i.e. 50 pg ml-1) is two-fold lower with respect to its threshold admitted in geldings plasma (100 pg ml-1 free testosterone). The high sensitivity and the quantitative aspect of the method permitted to detect most of steroids in equine serum. Once validated, the method was used to quantify 17 steroid hormones in mare, stallion and gelding serum samples. The main steroids detected were corticosterone (range 37.25-51.26 ng ml-1) and cortisol (range 32.57-52.24 ng ml-1), followed by 17-OH-pregnenolone, dihydrotestosterone and pregnenolone
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