LY191704: a selective, nonsteroidal inhibitor of human steroid 5 alpha-reductase type 1.
Androgens, in particular dihydrotestosterone (DHT), play a key role in differentiation, growth, and maintenance of the mammalian prostate. Production of DHT from testosterone is catalyzed by two distinct membrane-bound steroid 5 alpha-reductase [5 alpha-reductase; 3-oxo-5 alpha-steroid delta 4-dehydrogenase; 3-oxo-5 alpha-steroid:(acceptor) delta 4-oxidoreductase, EC 1.3.99.5] isozymes designated types 1 and 2. Benign prostatic hyperplasia (BPH), a disease that occurs almost universally in males, is characterized by obstructive and irritative urinary voiding symptoms and has been associated with an overproduction of DHT. Recently, steroidal inhibitors of 5 alpha-reductase type 2 have been used successfully for treatment of BPH. Described here is a nonsteroidal inhibitor of 5 alpha-reductase type 1, LY191704 (8-chloro-4-methyl-1,2,3,4,4a,5,6,10b-octaahydro-benzo[f]quinol in-3(2H)-one). This compound was identified based on its capacity to inhibit 5 alpha-reductase activity in a human genital skin fibroblast cell line (Hs68). Surprisingly, LY191704 is inactive when tested in freshly isolated prostate cells obtained from subjects with BPH, whereas previously described 4-azasteroids are active. LY191704 is, however, a potent inhibitor of the 5 alpha-reductase activity of BPH cells that have been maintained in culture. Analysis of human and rat 5 alpha-reductases expressed from transfected cDNAs in simian COS cells indicates that LY191704 is a specific noncompetitive inhibitor of the human 5 alpha-reductase type 1. Taken together, the results suggest that prostate cells have the capacity to express both 5 alpha-reductase isozymes and that LY191704 may be useful in treatment of human endocrine disorders associated with overproduction of DHT by 5 alpha-reductase type 1.
Lilly Research Laboratories, Eli Lilly and Company, Indianapolis, IN 46285.
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Hirsch
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Jones
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Audia
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Andersson
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McQuaid
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Stamm
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Neubauer
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Pennington
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Toomey
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Russell
D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase / Q000235:genetics; D058891:5-alpha Reductase Inhibitors; D000736:Androstenes / Q000494:pharmacology; D000818:Animals; D001378:Azasteroids / Q000494:pharmacology; D002460:Cell Line; D018120:Finasteride; D006801:Humans; D007527:Isoenzymes / Q000037:antagonists & inhibitors*; D007700:Kinetics; D008297:Male; D011467:Prostate / Q000201:enzymology*; D015363:Quinolones / Q000494:pharmacology*; D051381:Rats; D012867:Skin / Q000201:enzymology; D014162:Transfection
D058891:5-alpha Reductase Inhibitors; D000736:Androstenes; D001378:Azasteroids; D007527:Isoenzymes; D015363:Quinolones; C081531:8-chloro-4-methyl-1,2,3,4,4a,5,6,10b-octahydrobenzo(f)quinolin-3(2H)-one; D018120:Finasteride; D013741:3-Oxo-5-alpha-Steroid 4-Dehydrogenase