Concentrations of unconjugated 5α-androstane-3α,17β-diol and 5α-androstane-3β,17β-diol and their precursor in human testicular tissue. comparison with testosterone, 5α -dihydrotestosterone, estradiol-17β, and with steroid concentrations in human epididymis

Tamm, J.; Volkwein, U.; Kurniawan, E.; Becker, H.

doi:10.1016/0022-4731(87)90099-9

Cited by 15 publications

(7 citation statements)

References 13 publications

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“…The turnover half‐life of the endogenous EpiA pool appears to be higher than for the other steroids. The explanation for this phenomenon can be derived from the metabolism of EpiA: a high relative quantity of 5α‐androstane‐3β,17β‐diol (3bDiol) in contrast to 5α‐androstane‐3α,17β‐diol (3aDiol) is produced in human testicular tissue after the administration of dihydrotestosterone or 5EN17b,53 but almost no 3bDiol is found in human urine. The only urinary metabolite with a 3β‐hydroxy function is EpiA.…”

Section: Resultsmentioning

confidence: 99%

Photochromic Organometallics with a Dithienylethene (DTE) Bridge, [YCCDTECCY] (Y={MCp*(dppe)}): Photoswitchable Molecular Wire (M=Fe) versus Dual Photo‐ and Electrochromism (M=Ru)

Tanaka

Ishisaka

Inagaki

et al. 2010

Chemistry A European J

113

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Dinuclear acetylide-type complexes bridged by a photochromic dithienylethene unit (DTE), [Y-C[triple bond]C-DTE-C[triple bond]C-Y] 1 (Y={MCp*(dppe)}; Cp*=pentamethylcyclopentadienyl, M=Fe (1(Fe)), Ru (1(Ru))), have been prepared, and their wirelike and switching behavior, as well as their oxidation chemistry has been investigated. The DTE complexes 1 exhibit photochromic behavior in a manner similar to organic DTE derivatives; UV irradiation causes ring closure of the open isomer 1O to form the closed isomer 1C and visible-light irradiation of the resultant 1C causes reverse ring opening to regenerate 1O. But the performance is dependent on the metals. With respect to the interconversion rates and the 1C content at the photostationary state under UV irradiation, the ruthenium complex 1(Ru) is superior to the iron analogue 1(Fe). The wirelike performance is associated with the photochromic processes, and the efficient switching performance has been verified for 1(Fe) as characterized by the V(ab) values [V(ab) is the electronic coupling derived from intervalence charge-transfer (IVCT) bands: V(ab)(1(Fe)C; ON)=0.047 eV versus V(ab)(1(Fe)O; OFF)=0 eV], and are also supported by the large switching factor (SF=K(C)(C; ON)/K(C)(O; OFF)=39; K(C)=comproportionation constant). SF for 1(Ru) is determined to be 4.2. The remarkable switching behavior arises from the different pi-conjugated systems in the two isomeric forms, that is, cross-conjugated (1O) and fully conjugated pi-systems (1C). It was also found that, in contrast to the reversible redox behavior of the iron complex 1(Fe), the ruthenium complex 1(Ru)O undergoes oxidative ring closure to form the dicationic species of the closed isomer 1(Ru)C(2+) and, thus, the ruthenium system 1(Ru) shows dual photo- and electrochromism. The distinct oxidation behavior of 1(Fe) and 1(Ru) can be ascribed to the spin distribution on the diradical intermediates 1(Fe)O(2+) and 1(Ru)O(2+), as supported by DFT calculations.

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Section: Resultsmentioning

confidence: 99%

Photochromic Organometallics with a Dithienylethene (DTE) Bridge, [YCCDTECCY] (Y={MCp*(dppe)}): Photoswitchable Molecular Wire (M=Fe) versus Dual Photo‐ and Electrochromism (M=Ru)

Tanaka

Ishisaka

Inagaki

et al. 2010

Chemistry A European J

113

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“…It has been reported that testosterone, DHT, 3α-adiol and 3β-adiol are four androgenic steroids produced in testis in which testosterone is the most abundant androgen and the other three androgens are 1–10% of the amount of testosterone (Ruokonen et al . 1972, Tamm et al . 1987, Jarow & Zirkin 2005).…”

Section: Discussionmentioning

confidence: 99%

Testicular vs adrenal sources of hydroxy-androgens in prostate cancer

Zang

Taplin

Tamae

et al. 2017

Endocrine-Related Cancer

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Neoadjuvant androgen deprivation therapy (NADT) is one strategy for the treatment of early-stage prostate cancer; however, the long-term outcomes of NADT with radical prostatectomy including biochemical failure-free survival are not promising. One proposed mechanism is incomplete androgen ablation. In this study, we aimed to evaluate the efficiency of serum hydroxy-androgen suppression in patients with localized high-risk prostate cancer under NADT (leuprolide acetate plus abiraterone acetate and prednisone) and interrogate the primary sources of circulating hydroxy-androgens using our recently described stable isotope dilution liquid chromatography mass spectrometric method. For the first time, three androgen diols including 5-androstene-3β,17β-diol (5-adiol), 5α-androstane-3α,17β-diol (3α-adiol), 5α-androstane-3β,17β-diol (3β-adiol), the glucuronide or sulfate conjugate of 5-adiol and 3α-adiol were measured and observed to be dramatically reduced after NADT. By comparing patients that took leuprolide acetate alone vs leuprolide acetate plus abiraterone acetate and prednisone, we were able to distinguish the primary sources of these androgens and their conjugates as being of either testicular or adrenal in origin. We find that testosterone, 5α-dihydrotestosterone (DHT), 3α-adiol and 3β-adiol were predominately of testicular origin. By contrast, dehydroepiandrosterone (DHEA), epi-androsterone (epi-AST) and their conjugates, 5-adiol sulfate and glucuronide were predominately of adrenal origin. Our findings also show that NADT failed to completely suppress DHEA-sulfate levels and that two unappreciated sources of intratumoral androgens that were not suppressed by leuprolide acetate alone were 5-adiol-sulfate and epi-AST-sulfate of adrenal origin.

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“…However, the concentrations of testosterone (10 Ϫ7 mol/L) required for this apoptosis inhibiting effect were 100-1000 times the effective concentrations of estradiol (10 Ϫ9 -10 Ϫ10 mol/L). Of note, the relative potencies of testosterone and estradiol are in the range of their relative physiological concentrations in the spermatic vein (43)(44)(45)(46)(47) and testis tissue (48,49). In vivo, testosterone can be metabolized to either estrogens or DHT.…”

Section: Discussionmentioning

confidence: 99%

Estradiol Acts as a Germ Cell Survival Factor in the Human Testis in Vitro*

Pentikäinen

Erkkilä

Suomalainen

et al. 2000

The Journal of Clinical Endocrinology &Amp; Metabolism

116

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The necessity of estrogens for male fertility was recently discovered in studies on both estrogen receptor ␣ knockout and aromatase (cyp 19 gene) knockout mice. However, direct testicular effects of estrogens in male reproduction have remained unclear. Here we studied the protein expression of ER␣ and the recently described estrogen receptor ␤ in the human seminiferous epithelium and evaluated the role of 17␤-estradiol, the main physiological estrogen, in male germ cell survival. Interestingly, both estrogen receptors ␣ and ␤ were found in early meiotic spermatocytes and elongating spermatids of the human testis. Furthermore, low concentrations of 17␤-estradiol (10 Ϫ9 and 10 Ϫ10 mol/L) effectively inhibited male germ cell apoptosis, which was induced in vitro by incubating segments of human seminiferous tubules without survival factors (i.e. serum and hormones). Dihydrotestosterone, which, in addition to estradiol, is an end metabolite of testosterone, was also capable of inhibiting testicular apoptosis, but at a far higher concentration (10 Ϫ7 mol/L) than estradiol. Thus, estradiol appears to be a potent germ cell survival factor in the human testis. The novel findings of the present study together with the previously reported indirect effects of estrogens on male germ cells indicate the importance of estrogens for the normal function of the testis. (J Clin Endocrinol Metab 85: 2057-2067, 2000 R ECENT CONCERN over the potentially harmful effects of environmental estrogen-like chemicals on male fertility (1, 2) has aroused growing interest in understanding the physiological effects of estrogens in the male. Although estrogens have been regarded as female steroid hormones, they are now known to have profound effects on both female and male reproductive systems. In males, estrogens are synthesized mainly in the testis, where they are formed from testosterone by the enzyme P450 aromatase. In the rat, there is an age-related change in the aromatization site from Sertoli cells in the immature testis to Leydig cells in the adult testis (3, 4). In various other species, including humans, P450 aromatase has been found to be present in the Leydig cells of the adult testis (5-9). In addition, in the mouse (6), rat (7), brown bear (9), and rooster (10), aromatase has been found in meiotic and postmeiotic germ cells of the testis, predominantly in spermatids.Estrogens exert their cellular effects through estrogen receptors (ER) that exist in at least two subtypes, ER␣ (11, 12) and the recently described ER␤ (13, 14), which differ in the C-terminal ligand-binding domain and in the N-terminal trans-activation domain. These two subtypes of ER have similar high affinities for 17␤-estradiol, but some synthetic and naturally occurring ligands have different relative affinities for ER␣ and ER␤ (15). In the male reproductive tract, ER␣ has been shown to be strongly expressed in the epididymis and efferent ductules (16 -20). It has also been found in the Leydig cells of the rat testis (16), whereas the seminiferous epitheliu...

show abstract

Concentrations of unconjugated 5α-androstane-3α,17β-diol and 5α-androstane-3β,17β-diol and their precursor in human testicular tissue. comparison with testosterone, 5α -dihydrotestosterone, estradiol-17β, and with steroid concentrations in human epididymis

Cited by 15 publications

References 13 publications

Photochromic Organometallics with a Dithienylethene (DTE) Bridge, [YCCDTECCY] (Y={MCp*(dppe)}): Photoswitchable Molecular Wire (M=Fe) versus Dual Photo‐ and Electrochromism (M=Ru)

Photochromic Organometallics with a Dithienylethene (DTE) Bridge, [YCCDTECCY] (Y={MCp*(dppe)}): Photoswitchable Molecular Wire (M=Fe) versus Dual Photo‐ and Electrochromism (M=Ru)

Testicular vs adrenal sources of hydroxy-androgens in prostate cancer

Estradiol Acts as a Germ Cell Survival Factor in the Human Testis in Vitro*

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