BACKGROUND

<em>5α</em>-Reductase inhibitors (<em>5α</em>-RI) act by inhibiting the conversion of testosterone to dihydrotestosterone (<em>DHT</em>), thereby preventing <em>DHT</em> induced benign prostatic hyperplasia. The existing <em>5α</em>-RIs can be classified into two types: competitive and noncompetitive. Currently, limited evidence is available concerning the effect differences between the two types of <em>5α</em>-RI on androgens. The purpose of this study was to assess the effects of competitive and noncompetitive <em>5α</em>-RIs on serum and intra-prostatic androgens in beagle dogs.

METHODS

Twenty beagles with spontaneous benign prostatic hyperplasia were randomly allocated into two groups: epristeride group (n = 10) in which beagles were treated with epristeride at 1 mg/kg once a day for 3 months, and finasteride group (n = 10) in which beagles were treated with finasteride at 1 mg/kg once a day for 3 months. The levels of intra-prostatic testosterone and DHT were measured before treatment and on day one after three months medication. Serum levels of testosterone and DHT were measured at the same time points. Changes in androgen levels before and after treatment were analyzed, and comparisons were made within each treatment group and between treatment groups.

RESULTS

After 3-month treatment, serum and intra-prostatic DHT levels all decreased significantly in both the epristeride and finasteride groups. The change of DHT in serum was significantly higher in the finasteride group (-14% and -43% in epristeride and finasteride groups respectively, with P < 0.001); however there was no significant difference in the changes of intra-prostatic DHT between the two groups (-47% and -51% in epristeride and finasteride groups, respectively, P = 0.304). The decreases in DHT levels were accompanied by reciprocal increases in serum and intra-prostatic testosterone levels. Changes of testosterone were significantly higher in finasteride group both in serum (20% and 42% in epristeride and finasteride groups, respectively, P < 0.001) and in prostate tissue (18% and 29% in epristeride and finasteride groups, respectively, P = 0.004).

CONCLUSIONS

Two types of <em>5α</em>-RI have similar effects in reducing <em>DHT</em> in prostate tissue in beagles. Competitive <em>5α</em>-RI may reduce serum <em>DHT</em> to a greater scale, and significantly increase testosterone in beagle serum and prostate.

BACKGROUND

The clinical spectrum of <em>5α</em>-reductase deficiency, caused by mutations in the SRD5A2 gene, ranges from complete female appearance of the external genitalia at birth to nearly complete male phenotype.

METHODS

A 14-year-old girl presented with primary amenorrhea (PA) and lack of breast development. She was 173 cm in height, had an increased amount of pubic hair and clitoromegaly (3 cm), with a 4 cm blind vaginal pouch. Gonads were palpable in the inguinal canal bilaterally and no uterus was identified on ultrasound. Chromosomal analysis showed a 46,XY karyotype. The Testosterone/DHT ratio was high (16.5) and further increased to 29.4 after stimulation with hCG, thus favouring the diagnosis of <em>5α</em>-reductase deficiency. Since the issue of gender change was not considered, gonadectomy was performed followed by successful feminisation with hormonal replacement therapy.

UNASSIGNED

Molecular analysis of the SRD5A2 gene by DNA sequencing of all 5 exons revealed the presence of the splice mutation A>G at position -2 of the acceptor site of intron 1/exon 2 (IVS1-2A>G) in homozygosity. Both non-consanguineous parents were found to be heterozygotes for this mutation.

CONCLUSIONS

Although rare, SRD5A2 gene defect should be suspected in any girl presenting with PA and virilisation at puberty. The IVS1-2A>G mutation of the SRD5A2 gene predominates in Greek-Cypriot patients with <em>5α</em>-reductase deficiency and very likely reflects a founder effect.

This article summarizes the importance of different targets such as <em>5α</em>-reductase, 17β-HSD, CYP17A, androgen receptor and protein kinase A for the treatment of prostate cancer and benign prostatic hyperplasia. It is a well known fact that dihydrotestosterone (<em>DHT</em>) is associated with the development of androgen-dependent afflictions. At the present time, several research groups are attempting to develop new steroidal and non-steroidal molecules with the purpose of inhibiting the synthesis and biological response of <em>DHT</em>. This review also discusses the most recent studies reported in the literature that describe the therapeutic potential of novel compounds, as well as the new drugs, principally inhibitors of <em>5α</em>-reductase.

Androgen receptor (AR) signaling is crucial to the development and homeostasis of the prostate gland, and its dysregulation mediates common prostate pathologies. The mechanisms whereby AR regulates growth suppression and differentiation of luminal epithelial cells in the prostate gland and proliferation of malignant versions of these cells have been investigated in human and rodent adult prostate. However, the cellular stress response of human prostate epithelial cells is not well understood, though it is central to prostate health and pathology. Here, we report that androgen sensitizes HPr-1AR and RWPE-AR human prostate epithelial cells to cell stress agents and apoptotic cell death. Although <em>5α</em>-dihydrotestosterone (<em>DHT</em>) treatment alone did not induce cell death, co-treatment of HPr-1AR cells with <em>DHT</em> and an apoptosis inducer, such as staurosporine (STS), TNFt, or hydrogen peroxide, synergistically increased cell death in comparison to treatment with each apoptosis inducer by itself. We found that the synergy between <em>DHT</em> and apoptosis inducer led to activation of the intrinsic/mitochondrial apoptotic pathway, which is supported by robust cleavage activation of caspase-9 and caspase-3. Further, the dramatic depolarization of the mitochondrial membrane potential that we observed upon co-treatment with <em>DHT</em> and STS is consistent with increased mitochondrial outer membrane permeabilization (MOMP) in the pro-apoptotic mechanism. Interestingly, the synergy between <em>DHT</em> and apoptosis inducer was abolished by AR antagonists and inhibitors of transcription and protein synthesis, suggesting that AR mediates pro-apoptotic synergy through transcriptional regulation of MOMP genes. Expression analysis revealed that pro-apoptotic genes (BCL2L11/BIM and AIFM2) were <em>DHT</em>-induced, whereas pro-survival genes (BCL2L1/BCL-XL and MCL1) were <em>DHT</em>-repressed. Hence, we propose that the net effect of these AR-mediated expression changes shifts the balance of BCL2-family proteins, such that androgen signaling sensitizes mitochondria to apoptotic signaling, thus rendering HPr-1AR more vulnerable to cell death signals. Our study offers insight into AR-mediated regulation of prostate epithelial cell death signaling.

Regular resistance exercise induces skeletal muscle hypertrophy and improvement of glycemic control in type 2 diabetes patients. Administration of dehydroepiandrosterone (DHEA), a sex steroid hormone precursor, increases <em>5α</em>-dihydrotestosterone (<em>DHT</em>) synthesis and is associated with improvements in fasting blood glucose level and skeletal muscle hypertrophy. Therefore, the aim of this study was to investigate whether increase in muscle <em>DHT</em> levels, induced by chronic resistance exercise, can contribute to skeletal muscle hypertrophy and concomitant improvement of muscular glucose metabolism in type 2 diabetic rats. Male 20-week-old type 2 diabetic rats (OLETF) were randomly divided into 3 groups: sedentary control, resistance training (3 times a week on alternate days for 8 weeks), or resistance training with continuous infusion of a <em>5α</em>-reductase inhibitor (n = 8 each group). Age-matched, healthy nondiabetic Long-Evans Tokushima Otsuka (LETO) rats (n = 8) were used as controls. The results indicated that OLETF rats showed significant decrease in muscular DHEA, free testosterone, <em>DHT</em> levels, and protein expression of steroidogenic enzymes, with loss of skeletal muscle mass and hyperglycemia, compared to that of LETO rats. However, 8-week resistance training in OLETF rats significantly increased the levels of muscle sex steroid hormones and protein expression of steroidogenic enzymes with a concomitant increase in skeletal muscle mass, improved fasting glucose level, and insulin sensitivity index. Moreover, resistance training accelerated glucose transporter-4 (GLUT-4) translocation and protein kinase B and C-ζ/λ phosphorylation. Administering the <em>5α</em>-reductase inhibitor in resistance-trained OLETF rats resulted in suppression of the exercise-induced effects on skeletal muscle mass, fasting glucose level, insulin sensitivity index, and GLUT-4 signaling, with a decline in muscular <em>DHT</em> levels. These findings suggest that resistance training-induced elevation of muscular <em>DHT</em> levels may contribute to improvement of hyperglycemia and skeletal muscle hypertrophy in type 2 diabetic rats.

The effects of chronic Dioscorea esculenta administration and exercise training on muscle sex steroid hormone levels and insulin resistance in type 2 diabetes rats was assessed. Twenty-week-old male Otsuka Long Evans Tokushima Fatty (OLETF) rats were assigned randomly to the control, D. esculenta treatment, D. esculenta with <em>5α</em>-reductase inhibitor treatment, or the exercise training groups (running at 25 m/min for 1 h, 5 d/wk; n = 10 each group). Eight weeks of D. esculenta treatment or exercise training significantly attenuated the increase in plasma insulin and fasting glucose levels. Plasma and muscle concentrations of dehydroepiandrosterone and <em>5α</em>-dihydrotestosterone (<em>DHT</em>) and the expression of <em>5α</em>-reductase increased significantly in the D. esculenta-treated and exercise training groups, and both treatments led to the upregulation of glucose transporter-4 translocation with concomitant increases in PKB and PKC-ζ/λ phosphorylation. Furthermore, the glucose metabolic clearance rate, which represents insulin sensitivity, increased significantly in both the D. esculenta-treated and exercise training groups. These effects were suppressed by administration of the <em>DHT</em> synthetic inhibitor. Together, these findings suggest that the D. esculenta-induced increase in muscle sex steroid hormone levels helps decrease insulin resistance in type 2 diabetes.-Sato, K., Fujita, S., Iemitsu, M. Dioscorea esculenta-induced increase in muscle sex steroid hormones is associated with enhanced insulin sensitivity in a type 2 diabetes rat model.

Our previous study in male rats demonstrated that bilateral administration of flutamide, an androgen receptor (AR) antagonist, into the posterodorsal medial amygdala (MePD) increased the time sniffing male odors to as high as that sniffing estrous odors, eliminating the preference for estrous odors over male odors. This made us speculate that under blockade of AR in the MePD, testosterone-derived estrogen acting on the same brain region arouses interest in male odors which is otherwise suppressed by concomitant action of androgen. In cyclic female rats, endogenous androgen has been thought to be involved in inhibitory regulation of estrogen-activated sexual behavior. Thus, in the present study, we investigated the possibility that in female rats the arousal of interest in male odors is also normally regulated by both estrogen and androgen acting on the MePD, as predicted by our previous study in male rats. Implantation of either the estrogen receptor blocker tamoxifen (TX) or a non-aromatizable androgen <em>5α</em>-dihydrotestosterone (<em>DHT</em>) into the MePD of ovariectomized, estrogen-primed female rats eliminated preference for male odors over estrous odors by significantly decreasing the time sniffing male odors to as low as that sniffing estrous odors. The subsequent odor discrimination tests confirmed that the <em>DHT</em> and TX administration did not impair the ability to discriminate between male and estrous odors. These results suggest that in estrous female rats estrogen action in the MePD plays critical roles in the expression of the preference for male odors while androgen action in the same brain region interferes with the estrogen action.

Doping with natural steroids can be detected by evaluating the urinary concentrations and ratios of several endogenous steroids. Since these biomarkers of steroid doping are known to present large inter-individual variations, monitoring of individual steroid profiles over time allows switching from population-based towards subject-based reference ranges for improved detection. In an Athlete Biological Passport (ABP), biomarkers data are collated throughout the athlete's sporting career and individual thresholds defined adaptively. For now, this approach has been validated on a limited number of markers of steroid doping, such as the testosterone (T) over epitestosterone (E) ratio to detect T misuse in athletes. Additional markers are required for other endogenous steroids like dihydrotestosterone (<em>DHT</em>) and dehydroepiandrosterone (DHEA). By combining comprehensive steroid profiles composed of 24 steroid concentrations with Bayesian inference techniques for longitudinal profiling, a selection was made for the detection of <em>DHT</em> and DHEA misuse. The biomarkers found were rated according to relative response, parameter stability, discriminative power, and maximal detection time. This analysis revealed <em>DHT</em>/E, <em>DHT</em>/5β-androstane-3α,17β-diol and <em>5α</em>-androstane-3α,17β-diol/5β-androstane-3α,17β-diol as best biomarkers for <em>DHT</em> administration and DHEA/E, 16α-hydroxydehydroepiandrosterone/E, 7β-hydroxydehydroepiandrosterone/E and 5β-androstane-3α,17β-diol/<em>5α</em>-androstane-3α,17β-diol for DHEA. The selected biomarkers were found suitable for individual referencing. A drastic overall increase in sensitivity was obtained. The use of multiple markers as formalized in an Athlete Steroidal Passport (ASP) can provide firm evidence of doping with endogenous steroids.

Detrimental changes in body composition are often associated with declining levels of testosterone. Here, we evaluated the notion that multipotent mesenchymal stem cells, that give rise to both fat and muscle tissue, can play a significant role to alter existing body composition in the adult. Transgenic mice with targeted androgen receptor (AR) overexpression in stem cells were employed. Wild-type littermate and AR-transgenic male and female mice were gonadectomized and left untreated for 2 months. After the hypogonadal period, mice were then treated with <em>5α</em>-dihydrotestosterone (<em>DHT</em>) for 6 weeks. After orchidectomy (ORX), wild-type males have reduced lean mass and increased fat mass compared to shams. <em>DHT</em> treatment was beneficial to partially restore body composition. In wild-type females, ovariectomy (OVX) produced a similar change but there was no improvement with <em>DHT</em>. In targeted AR transgenic mice, <em>DHT</em> treatment increased lean and reduced fat mass to sham levels. In contrast to wild-type females, <em>DHT</em> treatment in female transgenic mice significantly ameliorated the increased fat and decreased lean mass changes that result after OVX. Our results show that <em>DHT</em> administration reduces fat mass and increases lean mass in wild-type males but not females, indicating that wild-type females are not as sensitive to androgen treatment. Because both male and female transgenic mice are more responsive than wild-type, results suggest that body composition remains linked to stem cell fate in the adult and that targeted androgen signaling in stem cells can play a significant role to reverse detrimental changes in body composition in both sexes.

Testosterone regulates a wide variety of behavioral and physiological traits in male vertebrates. It influences reproductive and aggressive behaviors and is used as a marker of gonadal activity. While testosterone is the primary biologically active male gonadal steroid in the blood, it is metabolized into a variety of related steroids when excreted via urine and feces. To monitor endocrinological profiles studies on wild-living animals primarily rely on non-invasively collected samples such as urine or feces. Since a number of androgen metabolites that are found in high concentrations in these matrices do not stem exclusively from gonadal production, but are also produced by the adrenal cortex, the metabolism and excretion pattern of testosterone and its characteristic metabolites have to be investigated. Here, we compare the levels of 11 androgens and their metabolites in serum and urine (after hydrolytic/solvolytic cleavage of conjugates) from female, and intact and castrated male chimpanzees to investigate whether they were of testicular or adrenal origin. For serum, significant differences in concentrations were found only for native testosterone. For urine, testosterone concentrations showed the largest differences between intact and castrated males, and intact males and females, while no differences were seen between females and castrated males. Epitestosterone levels revealed the same pattern. These differences in urinary concentrations could also be seen for <em>5α</em>-androstane-3α,17β-diol (androstanediol), and less clearly for <em>5α</em>-dihydrotestosterone (<em>5α</em>-<em>DHT</em>), etiocholanolone, and androsterone. In urine of males, significant correlations were found between the levels of testosterone and <em>5α</em>-androstane-3α,17β-diol, as well as between testosterone and epitestosterone. Therefore, the clearest urinary markers of gonadal activity in male chimpanzees seems to be testosterone itself.

The adipokine Chemerin and its receptor, chemokine-like receptor 1 (CMKLR1), are associated with osteoblastogenic differentiation of mesenchymal stem cells (MSCs) and osteoclastogenic differentiation of osteoclast precursors in vitro, suggesting that CMKLR1 would affect the bone mineral density (BMD). However, the role of CMKLR1 on BMD in vivo remains unknown. Here, using CMKLR1 knockout mouse model, we unveiled that CMKLR1 effected the amount of Leydig cells in testis and regulated androgen-dependent bone maintenance in male mice, which exhibited lower serum testosterone levels, thereby reducing the trabecular bone mass. Correspondingly, the mRNA expression of testosterone synthesis enzymes in testis decreased. The bone tissue also showed decreased mRNAs expression of osteogenic markers and increased mRNA levels for osteoclast markers. Furthermore, by in vitro differentiation models, we found CMKLR1-deficiency could break the balance between osteoblastogenesis and osteoclastogenesis that caused a shift from osteogenic to adipogenic differentiation in MSCs and enhanced osteoclast formation. In addition, bone mass increase in CMKLR1 KO male mice can be promoted by treatment with <em>5α</em>-dihydrotestosterone (<em>DHT</em>), and the inactivation of CMKLR1 in male wild-type (WT) mice with antagonist treatment can lead to low bone mass. Taken together, these data indicate that CMKLR1 positively regulates bone metabolism through mediating testosterone production and the balance between osteoblast and osteoclast formation.

<em>5α</em>-Dihydrotestosterone (<em>DHT</em>) is a potent androgen in mammals with multiple roles; however the physiological actions of <em>DHT</em> in male fishes are not well known. To address this knowledge gap, male mummichog (Fundulus heteroclitus) were continuously exposed to 0, 5, and 50 μg/L <em>DHT</em> for 21 days. Following exposure, testes were separated for histology, ex vivo incubation to measure steroidogenic capacity, and gene expression analyses (real-time PCR and microarray). <em>DHT</em> significantly decreased ex vivo 11-ketotestosterone (11KT) production in males exposed to 50 μg/L <em>DHT</em> but not 5 μg/L <em>DHT</em>, and <em>DHT</em> exposure did not affect ex vivo testosterone production. Histological examination revealed that the amount of interlobular and connective tissue present in the testes was increased in the 50 μg/L <em>DHT</em> treatment. Despite reductions in the production of 11KT, <em>DHT</em> did not affect the expression of targeted genes in the steroidogenic pathway such as steroidogenic acute regulatory protein (star), P450 side chain cleavage (cyp11a1) and 11β-hydroxysteroid dehydrogenase (hsd11b3). Microarray analysis in the testes of individuals from control and 50 μg/L <em>DHT</em> revealed that males exposed to 50 μg/L <em>DHT</em> showed regulated transcriptional sub-networks that were related to immunity, regulation of blood flow, lipids and xenobiotic clearance, suggesting that <em>DHT</em> may be involved in the physiological regulation of these processes in the fish testes. A second objective of this study was to determine the feasibility of measuring mRNA levels in tissues used for ex vivo steroid production by comparing RNA integrity and transcript levels in testes of both immediately flash frozen tissue and incubated tissue. There was no significant difference in RNA quality between the two time points, indicating RNA integrity can remain intact for at least 18 h in ex vivo assays, thereby providing a viable option for researchers assessing multi-level biological reproductive endpoints when limited tissue is available. While the gene expression levels of actb, efla, rps12, rps18, star, and hsd11b3 remained unchanged, esr2a (esrba), esr2b (esrbb) and cyp11a1 were significantly lower in incubated tissue compared to flash frozen tissue. Therefore caution must be used as the steady-state levels of select genes may change over time. This study improves our understanding of <em>DHT</em> action in the teleostean testis and generates new hypotheses regarding cell processes that are regulated by this underexplored and potent androgen.

Androgen deprivation therapy is the frontline treatment for metastatic prostate cancer; however, because the majority of cases of advanced prostate cancer progress to castration-resistant prostate cancer (CRPC), there is a considerable need to better understand the synthesis of intratumoral concentrations of the androgen receptor (AR) agonist, <em>5α</em>-dihydrotestosterone (<em>DHT</em>) in CRPC. In a recent article in the Proceedings of the National Academy of Sciences, Chang et al. show that, contrary to widely held assumptions, the dominant pathway to <em>DHT</em> synthesis does not involve testosterone as a precursor to <em>DHT</em>, but instead involves the conversion of Δ ( 4) -androstenedione (AD) to <em>5α</em>-dione (AD→<em>5α</em>-dione→<em>DHT</em>) by the steroid-<em>5α</em>-reductase isoenzyme 1 (SRD5A1). The authors show that it is this alternative pathway that drives the progression of CRPC, and they confirm these findings in six established human prostate cancer cell lines as well as in the metastatic tumors from two patients with CRPC. Such findings open the door to new areas of research and to the development of new therapeutic targets in CRPC.

Mesenchymal stem cells (MSCs) therapy has emerged as a potent therapeutic strategy to improve myocardial infarction. However MSCs therapy encounters a few obstacles regarding the poor viability of the transplanted cells. Therefore, it is important to explore a strategy to enhance post-transplanted MSC viability. To overcome this problem, several protocols were suggested mainly by activating PI3K/Akt pathway. The PI3K/Akt cascade regulates several cellular processes such as proliferation and apoptosis. Finasteride is a specific inhibitor of type II <em>5α</em>-reductase; the enzyme converts testosterone (T) to the more potent androgen receptor agonist dihydrotestosterone (<em>DHT</em>). Testosterone is found to stimulate rapid phosphorylation of Akt, and thereby activate the PI3K/Akt pathway. This pathway could lead to decreased apoptosis of the MSCs via increasing the expression of Bcl-2 and reducing Bax expression. It has been also reported that <em>DHT</em> would confine the differentiation capacity of MSCs so that a reduction in <em>DHT</em> levels caused by Finasteride would be accompanied by increased facilitation in differentiation of MSCs to cardiomyocyte by means of the signals originating from the injured cardiac tissue. These mechanisms could propose the potential role for Finasteride to improve the MSCs therapy for myocardial infarction.

In teleosts, spermatogenesis is regulated by pituitary gonadotropins and sex steroids. <em>5α</em>-dihydrotestosterone (<em>DHT</em>), derived from testosterone (T) through the action of <em>5α</em>-reductase, has recently been suggested to play a physiologically important role in some fish species. In this study, gilthead seabream, Sparus aurata L., males received an implant of 1μgT/g body mass (bm) or vehicle alone and, 7days later, 1mg finasteride (FIN, an inhibitor of <em>5α</em>-reductase)/kg bm or vehicle. Serum levels of T, 11-ketotestosterone (11KT), <em>DHT</em> and 17β-estradiol (E2), and the mRNA levels of the main enzymes involved in their synthesis, were analysed. T promoted a transient increase in the serum levels of T, 11KT and E2 but a decrease in those of <em>DHT</em> at day 15 following T injection, in accordance with the up-regulation of mRNA levels of the enzymes involved in T transformation to 11KT (coding genes: cyp11b1 and hsd11b) and the down-regulation of mRNA levels of the enzyme responsible for T transformation to <em>DHT</em> (coding gene: srd5a). Interestingly, a similar effect was observed when FIN was injected. However, when fish were injected with T and FIN successively (T+FIN), control levels were not recovered at the end of the experimental period (28days). <em>DHT</em> seems to regulate E2 serum levels via the down-regulation of mRNA levels of aromatase (coding gene: cyp19a1a), which is needed for the transformation of T into E2. The testis histology, together with the proliferative rates recorded upon T, FIN or T+FIN treatment, suggests that <em>DHT</em> is involved in the onset of the meiotic phase of spermatogenesis.

Adrenal C19 steroids serve as precursors to active androgens in the prostate. Androstenedione (A4), 11β-hydroxyandrostenedione (11OHA4) and 11β-hydroxytestosterone (11OHT) are metabolised to potent androgen receptor (AR) agonists, dihydrotestosterone (<em>DHT</em>), 11-ketotestosterone (11KT) and 11-ketodihydrotestosterone (11K<em>DHT</em>). The identification of 11OHA4 metabolites, 11KT and 11K<em>DHT</em>, as active androgens has placed a new perspective on adrenal C11-oxy C19 steroids and their contribution to prostate cancer (PCa). We investigated adrenal androgen metabolism in normal epithelial prostate (PNT2) cells and in androgen-dependent prostate cancer (LNCaP) cells. We also analysed steroid profiles in PCa tissue and plasma, determining the presence of the C19 steroids and their derivatives using ultra-performance liquid chromatography (UHPLC)- and ultra-performance convergence chromatography tandem mass spectrometry (UPC2-MS/MS). In PNT2 cells, sixty percent A4 (60%) was primarily metabolised to <em>5α</em>-androstanedione (<em>5α</em>DIONE) (40%), testosterone (T) (10%), and androsterone (AST) (10%). T (30%) was primarily metabolised to <em>DHT</em> (10%) while low levels of A4, <em>5α</em>DIONE and 3αADIOL (≈20%) were detected. Conjugated steroids were not detected and downstream products were present at <0.05μM. Only 20% of 11OHA4 and 11OHT were metabolised with the former yielding 11keto-androstenedione (11KA4), 11K<em>DHT</em> and 11β-hydroxy-<em>5α</em>-androstanedione (11OH-<em>5α</em>DIONE) and the latter yielding 11OHA4, 11KT and 11K<em>DHT</em> with downstream products <0.03μM. In LNCaP cells, A4 (90%) was metabolised to AST-glucuronide via the alternative pathway while T was detected as T-glucuronide with negligible conversion to downstream products. 11OHA4 (80%) and 11OHT (60%) were predominantly metabolised to 11KA4 and 11KT and in both assays more than 50% of 11KT was detected in the unconjugated form. In tissue, we detected C11-oxy C19 metabolites at significantly higher levels than the C19 steroids, with unconjugated 11K<em>DHT</em>, 11KT and 11OHA4 levels ranging between 13 and 37.5ng/g. Analyses of total steroid levels in plasma showed significant levels of 11OHA4 (≈230-440nM), 11KT (≈250-390nM) and 11K<em>DHT</em> (≈19nM). <em>DHT</em> levels (<0.14nM) were significantly lower. In summary, 11β-hydroxysteroid dehydrogenase type 2 activity in PNT2 cells was substantially lower than in LNCaP cells, reflected in the conversion of 11OHA4 and 11OHT. Enzyme substrate preferences suggest that the alternate pathway is dominant in normal prostate cells. Glucuronidation activity was not detected in PNT2 cells and while all T derivatives were efficiently conjugated in LNCaP cells, 11KT was not. Substantial 11KT levels were also detected in both PCa tissue and plasma. 11OHA4 therefore presents a significant androgen precursor and its downstream metabolism to 11KT and 11K<em>DHT</em> as well as its presence in PCa tissue and plasma substantiate the importance of this adrenal androgen.

Six sesquiterpenes: germacrone (1), zederone (2), dehydrocurdione (3), curcumenol (4), zedoarondiol (5) and isocurcumenol (6) were isolated from rhizomes of Curcuma aeruginosa Roxb. (Zingiberaceae). They inhibited <em>5α</em>-reductase which converts testosterone to dihydrotestosterone (<em>DHT</em>). Germacrone (1) was the most potent (IC(50)=0.42±0.05 mg/mL). Compound 1 was anti-androgenic in LNCaP cells when proliferation was testosterone-induced. The growth of flank gland of male Syrian hamsters is dependent on circulating androgen and when maintained with testosterone, 1 (3, 30, 100μg) inhibited growth but was ineffective against <em>DHT</em>. The similar activity profile was observed on the <em>5α</em>-reductase inhibitor, finasteride (100 μg) treatment group. The androgen receptor binding assay showed that 1 did not bind to the androgen receptor. In conclusion, 1 showed anti-androgenic effect on in vitro and in vivo assays. One of the possible mechanisms was inhibition <em>5α</em>-reductase activity. Thus, 1 is a potential lead compound for treatment of androgen-dependent disorders.

BACKGROUND

A variety of pharmaceuticals have been developed directed at mitigating the symptoms associated with benign prostatic hypertrophy (BPH) and have also been evaluated for their potential role in prevention and treatment of prostate cancer. One such agent is dutasteride , a non-selective inhibitor of <em>5α</em>-reductase, an enzyme responsible for conversion of testosterone to a more potent androgen dihydrotestosterone (<em>DHT</em>).

METHODS

This review will cover the safety profile of dutasteride when it is used in the treatment of prostate-related conditions, specifically looking at the pivotal clinical trials on this drug.

CONCLUSIONS

Dutasteride has proved to be a safe and efficacious treatment for symptoms related to BPH. The primary safety concern relates to the increased incidence of high-grade prostate cancer seen in men treated with dutasteride in the setting of prostate cancer prevention. Dutasteride has a role as an adjunct in the treatment of prostate cancer; however, this is an area still under active investigation. It is not recommended for use in prostate cancer prevention given the increased risk of high-grade cancers.

Changes in plasma androgen levels in asthmatic men may be linked to asthma severity, seemingly acting through nongenomic and genomic effects. Nongenomic effects include rapid relaxation of carbachol or antigenic challenge pre-contracted guinea pig airway smooth muscle (ASM) in vitro: testosterone (TES) blocks L-type voltage dependent Ca²⁺ channels, stored operated Ca²⁺ channels, inositol 1,4,5-trisphosphate receptors and promotes prostaglandin E₂ biosynthesis. In ASM at rest, TES lowers basal intracellular Ca²⁺ concentration and tension, maintaining a proper airway patency keeping steady smooth muscle tension and basal intracellular Ca²⁺ concentration at rest. Moreover, the bronchospasm in sensitized guinea-pigs was ablated by dehydroepiandrosterone (DHEA), a precursor of steroids, TES and its metabolites <em>5α</em>- and 5β-dihydrotestosterone (<em>DHT</em>). On the other hand, genomic effects related to androgenś anti-inflammatory properties in asthma have been recently studied. Briefly, TES negatively regulates type 2 immune response sustained by CD4+ Th2 and group 2 innate lymphoid cells, diminishing allergic airway inflammation in males. Also, novel findings establish that TES decreases interleukin (IL)-17A protein expression produced by CD4+ Th17 cells and therefore neutrophilic airway inflammation. Clearly, DHEA, TES or its 5β-reduced metabolite that possesses minimal androgenic effect, might have potential therapeutic capacities in the treatment of severe asthma via mechanisms distinct from corticosteroid treatment.

OBJECTIVE

To assess sex hormones in men with obesity and prostate cancer (PCa) and to study association between androgens and the pathogenesis biology of PCa in vitro.

METHODS

One hundred and eighty-one men older than 45 years selected from of a population attending to Urology departments screening for PCa, (78 participants without PCa and 103 patients with PCa). All participants were assessed for body mass index (BMI), age, Gleason score, and PSA. Endocrine profile was determined for LH, total testosterone (TT), 17β-estradiol (E2), prolactin and leptin. Biochemical profile (HbA1c, triacylglycerols and lipoproteins) was also determined. In vitro experiments were also performed, involving the study of <em>5α</em>-dihydrotestosterone (<em>DHT</em>) and E2 in the presence of adipocyte-conditioned medium (aCM).

RESULTS

All variables were continuous and described a Gaussian distribution unless mentioned. To determine the relation of aggressiveness, variable were transformed into categories. Thus, PCa aggressiveness is associated with the increase of age and BMI (p < .0001) but with is decreased with TT and E2 (p < .05). Moreover, adipocyte-secreted molecules increase aggressiveness of PCa cells in vitro. Lastly, DTH but not E2 enables invasiveness in vitro.

CONCLUSIONS

It was observed a coexistence of hormone axis profile alteration with sex hormones and BMI in PCa patients, in accordance with the new perspective of PCa pathogenesis.

Morphological and behavioural effects of testosterone (T) and of 5 α-dihydrotestosterone (<em>5α</em>-<em>DHT</em>) injected daily for a 3-week period at dosages of 0.5, 1, 5 and 10 mg for T and 1 and 5 mg for α-<em>DHT</em> were studied in the adult male castrated Japanese quail. Injections of 0.5 or 1.0 mg T produced only slight development of the cloacal gland while the other four treatments stimulated growth which reached maximal or submaximal values. Testosterone injections stimulated sexual activities; some such effects were also observed after treatment with <em>5α</em>-<em>DHT</em>. Although both steroids elicited crowing, there were qualitative differences between quails given <em>5α</em>-<em>DHT</em> and those given T and intacts. These differences were not due to the development of the sternotracheal (syringeal) muscles, the weights of which were increased and reached similar values in the <em>5α</em>-<em>DHT</em> and T (5 and 10 mg) treated males. These results are discussed in the context of our present knowledge of the mechanisms of regulation of reproduction processes by testosterone and its metabolites in birds.

In malignant breast tissue cytosols (n = 14), significantly high levels of oestradiol (E2), testosterone and <em>5a</em>-dihydrotestosterone (<em>DHT</em>) and sex hormone binding globulin (SHBG) were found as compared to breast tissue cytosols from normal women (n = 12) (p less than 0.001 for all parameters measured). In serum from the same patients and normal control groups no differences in these hormones or SHBG were detected, nor was relationship between serological and cytosolic levels observed. In the cytosol of the malignant group there was a significant correlation between testosterone and <em>DHT</em>, r = 0.98, p less than 0.001. This was also the case in the cytosol of normal breast tissue, r = 0.97, p less than 0.001. No such correlation between the two androgens was observed in the sera of either group. We hypothesise that the malignant breast is able to regulate its own hormonal milieu and that the nearly 8 times higher levels of intracellular SHBG compared to those in normal breast cytosol may be one the factors responsible for this accumulation of sex-steroids. In addition, SHBG due to its higher affinity for androgens than for E2 may shift the balance in favour of free oestrogens in malignant breast tissue.

It is not known whether local androgen metabolism is involved in the mechanisms underlying the dehydroepiandrosterone (DHEA) administration-induced improvement of bone mineral density (BMD) in an estrogen-deficiency state. The aim of the present study was to clarify whether DHEA administration would improve local androgen metabolism and BMD in cancellous site of tibia of ovariectomized (OVX) rats. Twenty-two female rats, 6 weeks old, were randomized into three groups: sham-operated rats, OVX control rats, and OVX rats that received DHEA treatment. DHEA was administered intraperitoneally at 20 mg/kg body weight for 8 weeks. The concentrations of free testosterone and dihydrotestosterone (<em>DHT</em>) in cancellous site of tibia did not change as a result of ovariectomy, while the <em>DHT</em> concentration increased following DHEA administration. We revealed that DHEA administration improved the reduction of 17β- and 3β-hydroxysteroid dehydrogenases and clearly reversed the reduction of <em>5α</em>-reductase types 1 and 2 and androgen receptor in the cancellous site of tibia of OVX rats. DHEA administration suppressed estrogen deficiency relative to the decrease in the cancellous BMD, which was positively associated with local <em>DHT</em> concentration. These findings indicate that DHEA administration enhances local bioactive androgen metabolism in the cancellous tibia of young OVX rats, suggesting that local <em>DHT</em> may play a part in the DHEA administration-induced improvement of cancellous BMD.

In vertebrates, androgens are essential in many biological functions, including reproduction, immune system, metabolism, cardiovascular function, and the central nervous system. The most potent androgen <em>5α</em>-dihydrotestosterone (<em>5α</em>-<em>DHT</em>), which is actively involved in sexual differentiation and development, is converted from testosterone (T) by the steroid <em>5α</em>-reductases type 1, 2, and 3 (Srd<em>5α</em>1, Srd<em>5α</em>2, and Srd<em>5α</em>3). Alternatively, steroid 5β-reductase (Srd5β) converts T to 5β-dihydrotestosterone (5β-<em>DHT</em>), a metabolite believed to be involved in steroid clearance. Recent studies suggested that Srd5 isoforms are targets for endocrine disruption. Thus, understanding the regulation of Srd5 is important to expand our knowledge on how exogenous compounds can interfere with these enzymes. In this study, we exposed frog brain, liver, and gonads ex vivo to T, <em>5α</em>-<em>DHT</em>, and 5β-<em>DHT</em> in order to investigate the regulation of srd5 in response to androgens as a simulation of endocrine disrupting chemicals with androgenic properties. Androgens did not modulate srd<em>5α</em>2, suggesting that this isoform is not regulated by T and <em>5α</em>-<em>DHT</em> in frogs. However, the DNA methylation of srd<em>5α</em>2 increased following <em>5α</em>-<em>DHT</em> treatment suggesting that androgens can modulate epigenetic mechanisms in amphibians. In contrast, the DNA methylation of srd<em>5α</em>1 and srd<em>5α</em>3 remained stable after androgen exposure, but the mRNA levels of srd<em>5α</em>1 and srd<em>5α</em>3 were modulated by T, <em>5α</em>-<em>DHT</em>, and 5β-<em>DHT</em> in a sex- and tissue-specific manner. While T positively regulates srd<em>5α</em>1 and srd<em>5α</em>3 in testes, T negatively regulates srd<em>5α</em>3 in ovaries. Moreover, exposure to T also increased the mRNA level of srd5β in the male brain suggesting a mechanism to protect the brain from androgen action by elimination of T into 5β-<em>DHT</em>. Thus, exogenous compounds with androgenic properties potentially interact with srd5 transcription and DNA methylation pattern, which could adversely affect biological functions of vertebrates during development and reproduction.