Male patients on testosterone replacement therapy, those with a past medical or family history of prostate cancer, those currently or with a history of using 5a-reductase
inhibitors (i.e., finasteride, dutasteride, and high-dose saw palmetto), or those with low 5a-reductase
activity as previously measured on a urine hormone profile are all candidates for further evaluation.
Primary prevention of PCa has focused on chemoprevention, vitamin supplements (selenium, Vitamin E, and Vitamin C), and 5a-reductase
inhibitors (finasteride and dutasteride).
Thigpen et al., Molecular Genetics of Steroid 5a-Reductase
2 Deficiency, 90 J.
Morton, "Inhibition of 5a-reductase
in genital skin fibroblasts and prostate tissue by dietary lignans and isoflavonoids," Journal of Endocrinology, vol.
The oligomeric stilbenes have been shown have many interesting biological activities such as: as inhibitor of 5a-reductase
(Hirano et al., 2001), scavenger of superoxide (Tanaka et al., 2000) and cytotoxic agents (Seo et al., 1999).
A second category of medicines includes what are termed the 5a-reductase
inhibitors, including Proscar and Avodart.
Finasteride, an inhibitor of 5a-reductase
, inhibits the conversion of testosterone to dihydrotestosterone, the primary androgen in the prostate, and may reduce the risk of prostate cancer.
Biochemical tests, imaging, chromosomal studies, and genetic testing were used to arrive at a diagnosis of 5a-reductase
(46) Repeating for emphasis: As more insulin is applied, more 5a-reductase
The Risks and Benefits of 5a-Reductase
Inhibitors for Prostate-Cancer Prevention.
Possible explanations are a lack of 5a-reductase
activity or, more likely, deficient progesterone as substrate.
They compared 2312 Icelandic men who underwent medical or surgical management for BPH (including treatment with 5a-reductase
inhibitors, which are known to lower the PSA concentration) vs 33 779 presumed-healthy Icelandic men.
The biologically active androgen dihydrotestosterone is produced from testosterone in the prostate by the action of type 1 and type 2 steroid 5a-reductase
The ratio of 5a-THF:THF served to assess activity of the cortisol-catabolizing enzyme 5a-reductase
relative to 5[beta]-reductase.
In other words, testosterone is a target hormone itself as well as a circulating prohormone for several target tissues that possess the converting enzymes 5a-reductase