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PubMed1996

5 alpha-reductase expression by prostate cancer cell lines and benign prostatic hyperplasia in vitro.

5 alpha-reductase (5 alpha R) activity in two human prostate cancer cell lines was compared to that in benign prostatic hyperplasia (BPH) tissue and COS cells transfected with and expressing the human genes for 5 alpha-reductase type 1 (5 alpha R1) and type 2 (5 alpha R2). Comparisons were based on pH profiles and sensitivities to selective inhibitors of 5 alpha-reductase In the cancer lines, activity was greatest over the pH range 7-8, compared to a sharp peak of activity between pH 5-5.5 in BPH tissue and COS cells expressing 5 alpha R2. Finasteride and SKF105,657 were potent inhibitors of 5 alpha-reductase activity in BPH tissue and COS cells expressing 5 alpha R2, but weak inhibitors in the cancer lines and in COS cells expressing 5 alpha R1. In contrast, UK117,026 was a more potent inhibitor of 5 alpha-reductase activity in the prostate cancer cell lines and in COS cells expressing 5 alpha R1. These data indicate that human prostate cancer cell lines express 5 alpha-reductase activity similar to that in COS cells transfected with 5 alpha R1, but different from that in BPH tissue. This may be a consequence of in vitro culture. Alternatively, it may reflect a change occurring as a result of neoplastic transformation in which case it will be important to select appropriate inhibitors in the clinic.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1996

Predominant expression of 5 alpha-reductase type 1 in pubic skin from normal subjects and hirsute patients.

Dihydrotestosterone (DHT), the 5 alpha-reduced metabolite of testosterone, is the active molecule triggering androgen action, and 5 alpha-reductase (5 alpha-R), the enzyme converting testosterone to DHT, is a key step in this mechanism. Skin, like prostate, is a DHT- dependent tissue. Our laboratory demonstrated, many years ago, that 5 alpha-R in external genitalia was not regulated by androgens, whereas it was androgen dependent in public skin. As two genes, 5 alpha-R types 1 and 2, encoding for 5 alpha-R enzymes have been recently cloned, we undertook the present study to determine whether the two enzymes we had postulated on the basis of regulation studies were coincident with the cloned isoforms. The expression of the two isoforms was studied in genital and pubic skin fibroblasts from normal men, normal women, and hirsute patients. Messenger ribonucleic acid analysis, using Northern blot and RT-PCR techniques, indicated that both 5 alpha-R1 and -2 messenger ribonucleic acids are expressed in genital skin as well as in public skin fibroblasts. In contrast, studies using specific inhibitors of 5 alpha-R1 (LY306089) and 5 alpha-R2 (finasteride) showed that 5 alpha-R2 is predominant in pubic skin of normal men, normal women, and hirsute patients. These data raise the question of the possible use of specific 5 alpha-R1 inhibitors in the treatment of idiopathic hirsutism.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed1999

A novel class of inhibitors for human steroid 5 alpha-reductase: phenoxybenzoic acid derivatives. I.

In a search for novel nonsteroidal inhibitors of human prostatic 5 alpha-reductase, we found a new series of phenoxybenzoic acid derivatives to be potent human prostatic 5 alpha-reductase inhibitors. Among them, 4-(biphenyl-4-yloxy)benzoic acid derivatives (2n, YM-31758), 2o and 2s showed more potent inhibitory activities than finasteride with IC50 values of 0.87, 0.67 and 0.56 nM, respectively. The optimized structures for the phenoxybenzoic acid derivatives 2d-2i were calculated by molecular modeling analysis, and the favorable distance between the carbon of the carboxyl group and the centroid of the phenyl group (benzene ring C) was found to be in the 9-11 A range.

5-alpha Reductase Inhibitors↗
PubMed1999

Synthesis and pharmacological evaluation of 4-halo progesterone derivatives as antiandrogen.

The pharmacological activity of eight pregnane derivatives 17-alpha acetoxyprogesterone 9, 17-alpha acetoxy-4, 5-epoxypregnan-3, 20-dione 10, 17-alpha acetoxy-4-chloro-4-pregnene-3, 20-dione 11, 17-alpha acetoxy-4-bromo-4-pregnene-3, 20-dione 12, 17-alpha hydroxy-4-bromo-4-pregnene-3, 20-dione 13, 4-chloro-17-alpha hydroxy-4-pregnene-3, 20-dione 14, 17-alpha benzoyloxy-4-bromo-4-pregnene-3, 20-dione 15 and 17-alpha benzoyloxy-4-chloro-4-pregnene-3, 20-dione 16 was determined. These compounds were evaluated as antiandrogens on gonadectomized hamster seminal vesicles. The pharmacological data in this study indicate that compounds 15 and 16 having a C-17 benzoyloxy moiety showed the highest antiandrogenic activity as measured by the reduction of the weight of the seminal vesicles, followed by the steroids 11 and 12 (17-alpha acetoxy group). The free alcohols 13 and 14 exhibited a lower antiandrogenic activity. Apparently, the ester moiety at C-17 is a necessary requirement for the presence of high antiandrogenic activity. Shows the inhibitory effect on the conversion of testosterone (T) to DHT, of the above described steroids as measured by the amount of produced DHT 2 expressed as pmoles of DHT/g of protein/h. Steroids 11, 12 and 16 showed a much higher inhibitory activity on the conversion of testosterone (T) to dihydrotestosterone (DHT) than presently used finasteride 3.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2000

A novel class of inhibitors for human steroid 5alpha-reductase: synthesis and biological evaluation of indole derivatives. II.

In a search for novel nonsteroidal inhibitors of human prostatic 5alpha-reductase, we found a new series of indole derivatives that showed potent inhibitory activities for the human enzyme. Among them, 4-[(1-benzyl-1H-indol-5-yl)oxyl-3-chlorobenzoic acid (2d, YM-32906) showed more potent inhibitory activity than finasteride with an IC50 value of 0.44 nM. 3-Chloro-4-[[1-(4-phenoxybenzyl)-1H-indol-5-yl]oxy]benzoic acid (2m) showed inhibitory activities for both human and rat prostatic 5alpha-reductase with IC50 values of 2.1 and 73 nM, respectively. The synthesis and structure-activity relationships of these indole derivatives are presented.

5-alpha Reductase Inhibitors↗
PubMed2004

Natural variability and the influence of concurrent control values on the detection and interpretation of low-dose or weak endocrine toxicities.

While defining the no effect level for the 5 alpha-reductase inhibitor finasteride in the Hershberger assay, we encountered an inverted-U low-dose trophic effect on the prostate gland of the rat. Two attempts to confirm this observation were unsuccessful, and we concluded that the positive effect initially observed was associated with normal biologic variability. During the same period we attempted, unsuccessfully, to repeat our own observation of weak uterotrophic activity in the rat for the sunscreen 3-(4-methylbenzylidene)camphor (4MBC). Further evaluation led us to conclude that 4MBC is uterotrophic only when the control uterine weights are at the low end of their normally encountered range. This led us to reevaluate our earlier mouse uterotrophic assay data for bisphenol A (BPA). Originally we had concluded that BPA gave irreproducible evidence of weak uterotrophic activity, but upon ordering the eight experiments we had conducted, according to decreasing control uterine weight, we confirmed reproducible weak uterotrophic activity for BPA when the control uteri were at the low end of their normal range. In this article, we describe these observations, together with a reanalysis of the data associated with several reported instances of weak or low-dose endocrine effects that have proven difficult to confirm in independent laboratories. These include the activity of BPA on the CF1 mouse prostate; the activities of BPA, octylphenol, and nonylphenol on the rat testis; and the effect of polycarbonate caging on control mouse uterine weight. In all of these cases, variability among controls provides a major obstacle to data interpretation and confirmation. Our recommendations on experimental design are also presented, with a view to ending the current impasse on the reality, or otherwise, of low-dose or weak endocrine toxicities.

Animals↗
PubMed2007

Histopathological changes induced by therapies in the benign prostate and prostate adenocarcinoma.

The effect of androgen deprivation and other hormonal therapies, radiation therapy, thermal ablation therapies, chemotherapy, and other systemic treatments is evident in the histology of non-neoplastic and neoplastic human prostate gland. Androgen deprivation may be achieved with: a. orchidectomy, b. exogenous oestrogen administration, c. drugs with the capacity to deplete the hypothalamus of luteinizing hormone-releasing hormone, d. antiandrogens administration: drugs, which block the conversion of testosterone to its active form of 5-alpha dihydrotestosterone (i.e. finasteride, dutasteride), and drugs which block the androgen receptor on individual cells (i.e. flutamide). Androgen deprivation therapies cause atrophy of non-neoplastic and neoplastic prostatic epithelium, as the result of apoptosis, and are mainly used as a palliative measure in metastatic prostate cancer or as neoadjuvant or adjuvant treatment, in clinically localized prostate cancer. Morphological tumour regression may complicate the recognition and grading of treated carcinomas in radical prostatectomy specimens. Radiation therapy may be applied in the form of external beam, interstitial implantation (brachytherapy), or a combination, as a mainstay or adjuvant (external beam) treatment in localized prostate cancer. The primary effect is the damage of endothelial cells, which cause ischemia that leads to atrophy. The difficulty of post-radiation prostate needle biopsy interpretation includes the distinction of treatment effect in normal prostatic tissue from recurrent or residual tumour. Histological changes after thermal ablation mainly include lesions observed in prostatic infarcts due to periurethral coagulative type necrosis of variable volume. The correlation between the histopathological effects of the above therapies and their clinical significance is not absolutely clear.

Adenocarcinoma↗
PubMed2002

Anti-androgens for the treatment of hirsutism.

Many alternatives exist for treating hirsutism. Based on an analysis of scientific literature and on the experiences of the author, the most common anti-androgen agents are discussed in this review. Androgen receptor blockers (cyproterone acetate, flutamide and spironolactone), 5 alpha-reductase inhibitors (finasteride) and androgen-suppressing agents (gonadotrophin-releasing hormone [GnRH] agonists, oestroprogestins, corticosteroids and insulin-sensitising agents) are evaluated and compared. The importance of diagnosis in choosing the most appropriate anti-androgen treatment is also discussed.

Androgen Antagonists↗
PubMed2006

Disease versus disease: how one disease may ameliorate another.

Systemic disease, either genetic or acquired, may prevent or decrease the severity of another disease. These observations have led to important therapeutic advances. The best-known examples are Edward Jenner's use in 1798 of cowpox to prevent smallpox and J.B. Haldane's 1942 observation that erythrocyte disorders such as thalassemia and sickle cell disease modify the severity of malaria. Patients with and carriers of cystic fibrosis may have genetic resistance to tuberculosis and/or secretory diarrhea. The beneficial effects of undernutrition have led to therapeutic diets for seizures, celiac disease, type 2 diabetes, and inflammatory bowel disease. Finasteride for prostatic hypertrophy was developed after the observation that patients with male pseudohermaphrodism resulting from 5-alpha-reductase mutations do not develop prostatic hypertrophy. Rh immunoglobulin for Rh hemolytic disease prevention followed the observation that ABO incompatibility prevented Rh sensitization. The natural immunosuppression of measles may cause remission of nephrosis, and that of leprosy prevents psoriasis. Patients with one form of agammaglobulinemia (X-linked) never get Epstein-Barr virus infection, and patients with another form (common variable) are seemingly cured by HIV infection. HIV/AIDS is prevented or modified by co-receptor mutations (notably the CCRDelta32 chemokine mutation), HIV-2, or GB virus C infection. Additional exploration of these genetic, infectious, and metabolic influences on disease severity may provide new therapeutic approaches to HIV and other diseases.

Disease↗
PubMed2002

The effect of phytosterols on quality of life in the treatment of benign prostatic hyperplasia.

In the United States, phytosterols are available as over-the-counter dietary supplements and are promoted as a safe and natural way to maintain a healthy prostate. In men with benign prostatic hyperplasia (BPH), evidence suggests that the agents improve urologic symptoms and flow measures to a greater extent than placebo and to a similar extent as finasteride. The primary goal for treating men with BPH is to reduce lower urinary tract symptoms and increase quality of life (QOL). Therefore, QOL has become an increasingly important end point in clinical trials. We reviewed all seven studies that determined the effect of phytosterols on QOL in patients with BPH. All trials assessed QOL with international prostate symptom score questions. Six studies found phytosterols to have beneficial effects on QOL; however, poor study design limits what can be learned from these evaluations. Most studies included a limited number of patients, and many were not placebo controlled. Since few of them evaluated the effect of phytosterols beyond 6 months, little evidence exists of the agents' long-term efficacy in reducing symptomatology or increasing QOL. Finally, phytosterols have not been adequately compared with alpha-blocking agents, one of the most widely administered and effective pharmacologic treatments of BPH. Larger studies comparing phytosterols with other treatments of BPH such as alpha-blockers should be conducted. In addition, a consensus should be reached as to which questionnaires are best to evaluate potential changes in QOL after treatment of BPH.

Clinical Trials as Topic↗
PubMed2000

Intermittent androgen deprivation in prostate cancer patients: factors predictive of prolonged time off therapy.

OBJECTIVES: We hypothesize that prostate cancer (PC) patients who achieve and maintain an undetectable prostate-specific antigen (UD-PSA) on androgen deprivation therapy (ADT) have a predominantly androgen-dependent cancer cell population sensitive to apoptosis that allows for a prolonged time off ADT. This study summarizes patient- and treatment-related factors associated with a prolonged time off ADT in patients electing intermittent androgen deprivation (IAD). METHODS: Hormone-naïve patients with PC were treated with ADT using an antiandrogen and a luteinizing-hormone-releasing hormone-agonist. Of 255 consecutive patients, 216 (85%) achieved a UD-PSA (< 0.05 ng/ml). Ninety-three (43%) of 216 elected to stop ADT after maintaining a UD-PSA for a median of one year. Patients were followed off therapy and advised to restart ADT if the PSA level reached > or = 5.0 ng/ml. Forty-one patients received finasteride as part of IAD induction and as maintenance off therapy; these patients are excluded from the current study and are the focus of another publication. The remaining 52 patients are assessable for response being either in the off-phase of IAD > or = 1 year or having restarted IAD. RESULTS: In the first IAD cycle, the median duration of the on-phase of IAD was 16 months (mean 19.0 months, range 3.6-71 months), and the median off-phase duration was 15.5 months (mean 24.1 months, range 3.2-87+ months). In 28 patients who maintained a UD-PSA for > or = 1 year, their median off-phase duration was 29 months (mean 35.8 months, range 7.8-87+ months), with nine (32%) still off IAD after a median follow-up of 62 months. Significant (p < 0.05) independent factors associated with prolonged off-phase duration by multivariate analysis included UD-PSA on ADT > or = 1 year (p = 0.010), PSA-only recurrence after local therapy (p = 0.039), and reaching a testosterone level > or = 150 ng/dl in > or = 4 months off ADT (p = 0.041). After a median of 66 months of follow-up, only one (2%) patient developed androgen-independent PC. CONCLUSIONS: Hormone-naïve patients who achieve and maintain a UD-PSA for at least one year during ADT may initiate IAD and anticipate a prolonged off-phase duration. Attainment of a UD-PSA on ADT may serve as an in vivo sensitivity test of a patient's tumor cell population, and allow for better selection of those best suited for IAD.

Aged↗
PubMed2006

Enhanced formation of non-phenolic androgen metabolites with intrinsic oestrogen-like gene transactivation potency in human breast cancer cells: a distinctive metabolic pattern.

Breast cancer is a sex steroid hormone-dependent malignant neoplasia. The role of oestradiol in this malignancy has been well documented; however, the involvement of androgens has remained controversial. To determine the role of non-phenolic androgen metabolites in human breast cancer, we studied the metabolism of [(14)C] testosterone and [(14)C] androstenedione in oestrogen-dependent MCF-7 cells and non-oestrogen-dependent MDA-MB 231 cells, at different substrate concentrations (1-10 muM) and time periods (30 min-48 h). Cultured non-oestrogen-dependent HeLa and yeast cells served as controls. Metabolites were identified and quantified by reverse isotope dilution. A distinctive pattern of androgen metabolism was identified in MCF-7 cells, being the 5alpha-androstane-3alpha,17beta-diol (3alpha,5alpha-diol) and its 3beta epimer (3beta,5alpha-diol), the major conversion products of testosterone (48.3%), with 5alpha-dihydrotestosterone as intermediary. The formation of 3alpha,5alpha-diol and 3beta,5alpha-diol (diols) was substrate concentration- and time-dependent, and abolished by finasteride. In contrast, very little of any diol formation was observed in MDA-MB 231, HeLa and yeast cell incubations. Additional enzyme gene expression studies revealed an overexpression of 5alpha-steroid reductase type-1 in MCF-7 cells, as compared with MDA-MB 231 cells. The oestrogen-like activities of diols were assessed in HeLa cells co-transfected with expression vectors for alpha or beta subtypes of the human oestrogen receptor (hER) genes and for an oestrogen-responsive reporter gene. The results show that 3beta, 5alpha-diol and to a lesser extent 3alpha,5alpha-diol bind with high relative affinity to hERalpha and hERbeta. Both diols induced hER-mediated reporter gene transactivation in a dose-response manner, similar to that induced by oestradiol, though with lower potency, an effect that was abolished by ICI-182 780. Furthermore, 3beta,5alpha-diol and to lesser extent 3alpha,5alpha-diol induced MCF-7 cell proliferation. The overall results demonstrated that MCF-7 cells exhibit enhanced expression and activity of androgen-metabolising enzymes, leading to rapid and large diol formation, and provide evidence that these androgen metabolites exert a potent oestrogen-agonistic effect, at genomic level, in oestrogen-dependent breast cancer cells. The data suggest that diols may act as in situ intracrine factors in breast cancer and that its formation can be pharmacologically inhibited.

Analysis of Variance↗
PubMed2001

A risk-benefit assessment of pharmacological therapies for hirsutism.

In recent years, many new therapeutic regimens for hirsutism have been introduced. This has considerably enlarged the different choices of the physician but at the same time has produced considerable confusion and uncertainty as to what is the best possible therapy for the single patient or for the different pathologies of this condition. This review presents data on the characteristics, adverse effects and effective dosage for the more commonly used drugs for hirsutism. In most patients, low doses of antiandrogens (cyproterone acetate, flutamide or spironolactone) are used with few adverse effects and good results in terms of improvement of the hirsutism. Patients with severe hyperandrogenic hirsutism may require larger doses of antiandrogens. In only a few patients, therapy with agents that primarily reduce androgen secretion (mostly a gonadotropin releasing hormone agonist) is needed. In responsive patients, dexamethasone may be used at low doses (associated with an antiandrogen) to prolong the length of the remission. Finally, agents that inhibit 5alpha-reductase activity (finasteride) may be used as alternative to low dose antiandrogen therapy but the results are often less satisfactory.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗
PubMed2006

Diagnosis and management of polycystic ovary syndrome: a practical guide.

Polycystic ovary syndrome (PCOS) is a syndrome, which can be defined as a group of recognisable patterns of symptoms or abnormalities that indicate a particular medical situation. The current definition of PCOS requires the presence of two of the following three conditions: (i) oligo- and/or anovulation; (ii) clinical and/or biochemical signs of hyperandrogenism; and (iii) polycystic ovaries--and the exclusion of other aetiologies. It is generally accepted that the prevalence of PCOS is approximately 5-10%, and that of polycystic ovaries alone is 21-23%. Other features of PCOS are obesity, insulin resistance, impaired glucose tolerance and type 2 diabetes mellitus, dyslipidaemia, cardiovascular disease, obstructive sleep apnoea and infertility. An approach to a patient with possible PCOS should be directed towards making a diagnosis and screening for associated endocrine abnormalities. Therapeutic interventions are directed towards addressing the needs of the patient at present and towards preventing long-term complications of the syndrome. Body mass index, which is a primary mediator in the relationship between PCOS and health-related quality of life in obese PCOS adolescents, may play a similar role in other PCOS patients. Any intervention directed at reducing central obesity will not only improve quality of life but also correct hyperinsulinism and improve fertility and lipid and androgen profiles. It is also the only currently available intervention that can have a lifelong impact on reducing possible long-term complications of the syndrome. Lifestyle modification is the cardinal intervention. Pharmacological treatments are available for specific indications. Infertility can be treated with clomifene (clomiphene citrate), metformin, gonadotropins or surgery to the ovaries. Cyproterone (alone or in combination with ethinylestradiol) and spironolactone are the main drugs used in the treatment of hirsutism. Other drugs that can be considered include flutamide, ketoconazole and finasteride. Women with PCOS require ongoing surveillance to detect impaired glucose tolerance, hyperlipidaemia, endometrial hyperplasia and consequent complications. Obese women, in particular, require regular glucose tolerance testing because of the potential for rapid progression from normal to impaired glucose tolerance and diabetes. The focus of this article is the epidemiology, diagnosis and management of this common endocrine disorder. Diagnostic and co-morbid features are discussed separately to facilitate understanding of PCOS. Symptom-directed strategies, as well as short- and long-term goals of treatment, are outlined.

Female↗
PubMed2005

Recent advances in the chemistry and pharmacological activity of new steroidal antiandrogens and 5 alpha-reductase inhibitors.

The object of this paper is to summarize for the past two years the most recent development in the field of prostate cancer and 5 alpha-reductase inhibitors. In addition we are also including some results on the synthesis and pharmacological evaluation of new steroidal compounds developed in our laboratory. Most of the new steroidal derivatives are based on the progesterone skeleton and showed a high inhibitory activity for the enzyme 5 alpha-reductase. Presently, similar compounds are used for the treatment of androgen dependent diseases such as: hirsutism, androgenic alopecia, benign prostatic hyperplasia and prostate cancer. Dihydrotestosterone 2 (Fig. 1) a 5 alpha-reduced metabolite of testosterone 1 has been implicated as a causative factor for the progression of these diseases, largely through the clinical evaluation of males who are genetically deficient of the enzyme steroid 5 alpha-reductase. As a result of this study, the inhibition of this enzyme has become a pharmacological strategy for the design and synthesis of new antiandrogenic drugs. The advent of finasteride 7 (Fig. 3) a 5 alpha-reductase inhibitor has greatly alleviated the symptoms associated with benign prostatic hyperplasia. In our laboratory, we recently synthesized several new 16 beta-methylpregnadiene-3,20-diones: 40, 41 (Fig. 8), 16 beta-phenylpregnadiene-3,17a-dione derivatives 46 and 47 (Fig. 9) and 49 (C-4 bromoderivative) (Fig. 11), 52-56 (Fig. 13). The analogue pregnatriene derivatives were also prepared: 44, 45 (Fig. 9) 50, 51 (Fig. 11) and 57-60 (Fig. 13) These compounds were evaluated as 5 alpha-reductase inhibitors in the following biological models: Penicillium crustosum broths, the flank organs of gonadectomized male hamsters, the incorporation of radiolabeled sodium acetate into lipids, the effect of the new steroids on the reduction of the weight of the seminal vesicles and on the in vitro metabolism of [3H]T to [3H]DHT in seminal vesicles of homogenates of gonadectomized male hamsters. All trienones 44, 45, 50, 51 and 57-60 in all biological models showed consistently a higher 5 alpha-reductase inhibitory activity than the corresponding dienones: 40, 41, 46, 47, 49 and 52-56. We believe that with these compounds the 5 alpha-reductase enzyme is inactivated by an irreversible Michael type addition of the nucleophilic portion of the enzyme to the conjugated double bond of the steroid. The trienones having a more coplanar structure react faster with the enzyme thus showing a higher inhibitory activity.

Androgen Antagonists↗
PubMed2006

Inhibitors of 5alpha-reductase in the treatment of benign prostatic hyperplasia.

The description of 5alpha-reductase deficiency in male pseudohermaphroditism, characterization of type-1 and type-2 isoenzymes of 5alpha-reductase, and development of 4-aza steroid competitive inhibitors of 5alpha-reductase were milestones in the development of 5alpha-reductase inhibitors, a class of drugs approved for the treatment of symptomatic benign prostatic hyperplasia (BPH). Stromal and epithelial hyperplasia in the region of the prostate that surrounds the urethra begins in the fourth decade of life and by the sixth decade, the prevalence is 50%. Benign prostatic hyperplasia is a frequent cause of lower urinary tract symptoms, urinary tract infection, and acute urinary retention requiring surgical intervention. Medical options for treatment of symptomatic BPH include 1) the 5alpha-reductase inhibitors finasteride and dutasteride, 2) the alpha1-adrenergic antagonists doxazocin, terazosin, tamsulosin, and alfuzosin, and 3) the combination of a 5alpha-reductase inhibitor and a alpha1-adrenergic antagonist. By inhibiting the production of dihydrotestosterone (DHT) locally within the prostate gland, 5alpha-reductase inhibitors have the effect of reducing prostate volume, improving lower urinary tract symptoms, increasing peak urinary flow, and decreasing the risk of acute urinary retention and need for surgical intervention. Alpha-1 adrenergic antagonists relax the smooth muscle of the bladder neck and prostate, thereby decreasing the resistance to urine flow and increasing peak urinary flow and improving lower urinary tract symptoms. The alpha1-adrenergic antagonists are effective in the short-term, and reduce clinical progression of BPH, but do not reduce the long-term risk of urinary retention or need for surgical intervention. The 5alpha-reductase inhibitors are effective in the long-term, especially in men with large prostates, and reduce the clinical progression of BPH, and further reduce the long-term risk of urinary retention and need for surgical intervention. The combination of a 5alpha-reductase inhibitor and a alpha1-adrenergic antagonist significantly reduces the clinical progression of BPH over either drug class alone.

Cholestenone 5 alpha-Reductase↗
PubMed2000

Targets for steroid hormone mediated actions of periodontal pathogens, cytokines and therapeutic agents: some implications on tissue turnover in the periodontium.

This review attempts to encapsulate the relevance of steroid hormone action in the periodontal tissues, during inflammation, repair and in response to current treatment modalities. Periodontal pathogens metabolise steroid hormones which could contribute to their nutritional requirements and host evasion mechanisms, by forming capsular proteins; their culture supernatants stimulate the synthesis of physiologically active steroid hormones by fibroblasts, which aid inflammatory repair. The functions of glucocorticoids, androgens, oestrogen and progesterone on connective tissue and bone, are applicable to the periodontium, being target tissue. This results in physiological effects on these tissues, during puberty, the menstrual cycle, pregnancy and the menopause. The effects of oral contraceptives and hormone replacement therapy on the periodontium have focused interest in the relationship between sex steroid hormones and periodontal health. Receptor expression and the role of the specific enzyme inhibitors, such as the anti-androgen finasteride and the anti-oestrogen tamoxifen, confirm target tissue activity for steroid hormones in the periodontium. The pro-anabolic and anti-inflammatory actions of tetracyclines, are an intriguing model for hormone mediated pathways of action. The effects of the specific alkaline phosphatase inhibitor levamisole on matrix turnover are linked to steroid hormone action, with direct implications on the healing periodontium. Drugs which contribute to gingival overgrowth are an interesting model, for explanation of an exaggerated 'scar tissue' response mediated by hormones, cytokines and a variety of enzyme systems. Cell dynamics of the periodontium plays an important role in co-ordinating the diverse interactions between steroid hormones and therapeutic agents.

Animals↗
PubMed2003

Steroid 5alpha-reductase inhibitors.

The objective of this study is to synthesize new steroidal compounds based on the progesterone skeleton with a high inhibitory activity for the enzyme 5alpha-reductase. Presently similar compounds are being used for the treatment of androgen dependent diseases such as: hirsutism, androgenic alopecia, bening prostatic hyperplasia and prostate cancer. Dihydrotestosterone 2 (Fig. (1)), a 5alpha-reduced metabolite of testosterone 1 has been implicated as a causative factor in the progression of these diseases, largely through the clinical evaluation of males who are genetically deficient of steroid 5alpha-reductase enzyme. As a result of this study, the inhibition of this enzyme has become a pharmacological strategy for the design and synthesis of new antiandrogenic drugs. The advent of finasteride 8 (Fig. (4)) a 5alpha-reductase inhibitor has grately alleviated the symptoms associated with benign prostatic hyperplasia. In our laboratory we recently synthesized several new 16beta-methyl-pregnadiene-3,20-diones derivatives 27 (Fig.(6)), 38-42 (Fig. (11)), 16beta-phenyl-pregnadiene-3,17a-dione derivatives 32-33 (Fig. (7)), 16beta-phenyl-pregnatriene-3,17a-diones, 30, 31 (Fig. (7)) and 16beta-methyl-pregnatriene-3,20-diones 43-46 (Fig. (11)). These compounds were evaluated as 5alpha-reductase inhibitors in the following biological models: Penicillium crustosum broths, the flank organs of gonadectomized male hamsters, the incorporation of radiolabeled sodium acetate into lipids, the effect of the new steroids on the reduction of the weight of the seminal vesicles and on the in vitro metabolism of [(3)H]T to [(3)H]DHT in seminal vesicles homogenates of gonadectomized male hamsters. All trienones 30, 31, and 43-46 in all biological models showed consistently a higher 5alpha-reductase inhibitory activity than the corresponding dienones 27, 32, 33 and 38-42. We believe that with these compounds the 5alpha-reductase enzyme is inactivated by an irreversible Michael type addition of the nucleophilic portion of the enzyme to the conjugated double bond of the steroid. The trienones having a more coplanar structure react faster with the enzyme and thus show a higher inhibitory activity.

3-Oxo-5-alpha-Steroid 4-Dehydrogenase↗