Document Detail

Steroid 5-alpha reductase type 2 activity in biopsies from malignant and normal prostatic tissues.
MedLine Citation:
PMID:  18328817     Owner:  NLM     Status:  MEDLINE    
BACKGROUND: The conversion of testosterone (T) to the more potent metabolite dihydrotestosterone (DHT) by prostate-specific steroid 5 alpha-reductase isoenzymes is a key mechanism in the action of androgens in the prostate and it is important in the promotion and progression of prostate diseases. We described an adaptation of a sensitive method for evaluation of the 5 alpha-reductase type 2 (5 alpha-R2) activity using a small quantity of protein. METHODS: We used 29 human prostate transrectal ultrasound-guided core biopsies obtained from patients (median age 70, range 55-86 y) undergoing this procedure for diagnostic purposes. 4-[(14)C]testosterone and NADPH were incubated with biopsy homogenate. Reaction products were extracted, separated by thin layer chromatography and revealed by autoradiography. Areas correspondent to T and DHT were scraped into vials and their radioactivity determined. RESULTS: The 5 alpha-R2 activity was expressed as ln (natural logarithm). The assay was validated according to the protein concentration and incubation time linearities. The 5 alpha-R2 activity showed a significant difference between normal and neoplastic tissues with significance level set at P<0.05, mainly in the left prostate lobe. This was independent from the PSA levels. CONCLUSIONS: Determination of 5 alpha-R2 activity, using the conditions reported herein, could be utilized as an efficient biochemical parameter of prostate neoplastic processes.
Osmar Luiz Magalhães Oliveira; Walter José Koff; Francine Muraro; Emanuel Burck Santos; Daniel Freitas Gomes Soares; Vera Maria Treis Trindade
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Publication Detail:
Type:  Comparative Study; Evaluation Studies; Journal Article; Research Support, Non-U.S. Gov't     Date:  2008-02-11
Journal Detail:
Title:  Clinica chimica acta; international journal of clinical chemistry     Volume:  391     ISSN:  0009-8981     ISO Abbreviation:  Clin. Chim. Acta     Publication Date:  2008 May 
Date Detail:
Created Date:  2008-05-20     Completed Date:  2008-07-25     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  1302422     Medline TA:  Clin Chim Acta     Country:  Netherlands    
Other Details:
Languages:  eng     Pagination:  36-40     Citation Subset:  IM    
Urology Service, Hospital de Clínicas de Porto Alegre, Rua Ramiro Barcelos 2350, Porto Alegre, RS, Brazil.
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MeSH Terms
Aged, 80 and over
Dihydrotestosterone / metabolism*
Middle Aged
Prostate / enzymology*
Prostatic Hyperplasia / enzymology*
Prostatic Neoplasms / enzymology*
Testosterone / metabolism*
Testosterone 5-alpha-Reductase / metabolism*
Reg. No./Substance:
521-18-6/Dihydrotestosterone; 58-22-0/Testosterone; EC 5-alpha-Reductase

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine

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