ExcelMale
Menu
Home
What's new
Latest activity
Forums
New posts
Search forums
What's new
New posts
Latest activity
Videos
Lab Tests
Doctor Finder
Buy Books
About Us
Men’s Health Coaching
Log in
Register
What's new
Search
Search
Search titles only
By:
New posts
Search forums
Menu
Log in
Register
Navigation
Install the app
Install
More options
Contact us
Close Menu
Forums
Testosterone Replacement, Low T, HCG, & Beyond
Testosterone and Men's Health Articles
New 5-alpha reductase enzyme found in testes
JavaScript is disabled. For a better experience, please enable JavaScript in your browser before proceeding.
You are using an out of date browser. It may not display this or other websites correctly.
You should upgrade or use an
alternative browser
.
Reply to thread
Message
<blockquote data-quote="Jerry Brainum" data-source="post: 4954" data-attributes="member: 162"><p>Issue </p><p><img src="https://onlinelibrary.wiley.com/store/10.1002/pros.v74.3/asset/cover.gif?v=1&111eebeb" class="bbImage" alt="" data-url="https://onlinelibrary.wiley.com/store/10.1002/pros.v74.3/asset/cover.gif?v=1&111eebeb" style="" /></p><p></p><p><strong>The Prostate</strong></p><p></p><p><a href="http://onlinelibrary.wiley.com/doi/10.1002/pros.v74.3/issuetoc" target="_blank">Volume 74, Issue 3, </a> pages 235–249, February 2014</p><p></p><p></p><p></p><p></p><p></p><p></p><p></p><p>Original Article</p><p></p><p><strong>5α-reductase type 3 enzyme in benign and malignant prostate</strong></p><p></p><p></p><p><strong>Abstract</strong></p><p></p><p> <strong>BACKGROUND</strong></p><p></p><p>Currently available 5α-reductase inhibitors are not completely effective for treatment of benign prostate enlargement, prevention of prostate cancer (CaP), or treatment of advanced castration-recurrent (CR) CaP. We tested the hypothesis that a novel 5α-reductase, 5α-reductase-3, contributes to residual androgen metabolism, especially in CR-CaP.</p><p></p><p></p><p> <strong>METHODS</strong></p><p></p><p>A new protein with potential 5α-reducing activity was expressed in CHO-K1 cellsandTOP10 <em>E. coli</em> for characterization. Protein lysates and total mRNA were isolated from preclinical and clinical tissues. Androgen metabolism was assessed using androgen precursors and thin layer chromatography or liquid chromatography tandem mass spectrometry.</p><p></p><p></p><p> <strong>RESULTS</strong></p><p></p><p>The relative mRNA expression for the three 5α-reductase enzymes in clinical samples of CR-CaP was 5α-reductase-3 ≫ 5α-reductase-1 > 5α-reductase-2. Recombinant 5α-reductase-3 protein incubations converted testosterone, 4-androstene-3,17-dione (androstenedione) and 4-pregnene-3,20-dione (progesterone) to dihydrotestosterone, 5α-androstan-3,17-dione, and 5α-pregnan-3,20-dione, respectively. 5α-Reduced androgen metabolites were measurable in lysates from androgen-stimulated (AS) CWR22 and CR-CWR22 tumors and clinical specimens of AS-CaP and CR-CaP pre-incubated with dutasteride (a bi-specific inhibitor of 5α-reductase-1 and 2).</p><p></p><p></p><p> <strong>CONCLUSION</strong></p><p></p><p>Human prostate tissues contain a third 5α-reductase that was inhibited poorly by dutasteride at high androgen substrate concentration in vitro, and it may promote DHT formation in vivo, through alternative androgen metabolism pathways when testosterone levels are low. <em>Prostate 74:235–249, 2014</em>. © 2013 Wiley Periodicals, Inc.</p></blockquote><p></p>
[QUOTE="Jerry Brainum, post: 4954, member: 162"] Issue [IMG]https://onlinelibrary.wiley.com/store/10.1002/pros.v74.3/asset/cover.gif?v=1&111eebeb[/IMG] [B]The Prostate[/B] [URL="http://onlinelibrary.wiley.com/doi/10.1002/pros.v74.3/issuetoc"]Volume 74, Issue 3, [/URL] pages 235–249, February 2014 Original Article [B]5α-reductase type 3 enzyme in benign and malignant prostate[/B] [B]Abstract[/B] [B]BACKGROUND[/B] Currently available 5α-reductase inhibitors are not completely effective for treatment of benign prostate enlargement, prevention of prostate cancer (CaP), or treatment of advanced castration-recurrent (CR) CaP. We tested the hypothesis that a novel 5α-reductase, 5α-reductase-3, contributes to residual androgen metabolism, especially in CR-CaP. [B]METHODS[/B] A new protein with potential 5α-reducing activity was expressed in CHO-K1 cellsandTOP10 [I]E. coli[/I] for characterization. Protein lysates and total mRNA were isolated from preclinical and clinical tissues. Androgen metabolism was assessed using androgen precursors and thin layer chromatography or liquid chromatography tandem mass spectrometry. [B]RESULTS[/B] The relative mRNA expression for the three 5α-reductase enzymes in clinical samples of CR-CaP was 5α-reductase-3 ≫ 5α-reductase-1 > 5α-reductase-2. Recombinant 5α-reductase-3 protein incubations converted testosterone, 4-androstene-3,17-dione (androstenedione) and 4-pregnene-3,20-dione (progesterone) to dihydrotestosterone, 5α-androstan-3,17-dione, and 5α-pregnan-3,20-dione, respectively. 5α-Reduced androgen metabolites were measurable in lysates from androgen-stimulated (AS) CWR22 and CR-CWR22 tumors and clinical specimens of AS-CaP and CR-CaP pre-incubated with dutasteride (a bi-specific inhibitor of 5α-reductase-1 and 2). [B]CONCLUSION[/B] Human prostate tissues contain a third 5α-reductase that was inhibited poorly by dutasteride at high androgen substrate concentration in vitro, and it may promote DHT formation in vivo, through alternative androgen metabolism pathways when testosterone levels are low. [I]Prostate 74:235–249, 2014[/I]. © 2013 Wiley Periodicals, Inc. [/QUOTE]
Insert quotes…
Verification
Post reply
Share this page
Facebook
Twitter
Reddit
Pinterest
Tumblr
WhatsApp
Email
Share
Link
Sponsors
Forums
Testosterone Replacement, Low T, HCG, & Beyond
Testosterone and Men's Health Articles
New 5-alpha reductase enzyme found in testes
This site uses cookies to help personalise content, tailor your experience and to keep you logged in if you register.
By continuing to use this site, you are consenting to our use of cookies.
Accept
Learn more…
Top