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1.
OBJECTIVES: To evaluate the response of testicular androgen ablation in patients with advanced prostate cancer with a biochemical recurrence after finasteride or combined finasteride and flutamide therapy. METHODS: Eighteen hormone na?ve men with advanced prostate cancer (10 with detectable prostate-specific antigen [PSA] levels after radical prostatectomy, 4 with rising PSA levels after definitive radiation therapy, and 4 with Stage D2 disease) were treated with finasteride (5 mg/day) alone or in combination with flutamide (250 mg three times a day). All men experienced an initial reduction in serum PSA, but later had treatment failure with two consecutive rising PSA measurements. All men were then treated with testicular androgen ablation (bilateral orchiectomy in 15 and luteinizing hormone-releasing hormone analogue in 3). RESULTS: Overall, serum PSA declined by more than 80% in 15 (83%) of 18 and to undetectable levels in 14 (78%) of 18. With a median+/-semi-interquartile range follow-up of 22+/-14.5 months from the initiation of hormone therapy, 12 (67%) of 18 currently have undetectable PSA levels. Two men having rising serum PSA levels above 100 ng/mL and 1 man has died from complications of metastatic prostate cancer. CONCLUSIONS: Testicular androgen ablation effectively lowers serum PSA levels in most men with advanced prostate cancer who have experienced a biochemical recurrence despite initial response and subsequent relapse on finasteride or combined finasteride and flutamide therapy.  相似文献   

2.
OBJECTIVE: The biological role of the adrenal sex steroid precursors--DHEA and DHEA sulphate (DS) and their decline with ageing remains undefined. We observed previously that administration of a 50 daily dose of DHEA for 3 months to age-advanced men and women resulted in an elevation (10%) of serum levels of insulin-like growth factor-I (IGF-I) accompanied by improvement of self-reported physical and psychological well-being. These findings led us to assess the effect of a larger dose (100 mg) of DHEA for a longer duration (6 months) on circulating sex steroids, body composition (DEXA) and muscle strength (MedX). SUBJECTS AND DESIGN: Healthy non-obese age-advanced (50-65 yrs of age) men (n = 9) and women (n = 10) were randomized into a double-blind placebo-controlled cross-over trial. Sixteen subjects completed the one-year study of six months of placebo and six months of 100 mg oral DHEA daily. MEASUREMENTS: Fasting early morning blood samples were obtained. Serum DHEA, DS, sex steroids, IGF-I, IGFBP-1, IGFBP-3, growth hormone binding protein (GHBP) levels and lipid profiles as well as body composition (by DEXA) and muscle strength (by MedX testing) were measured at baseline and after each treatment. RESULTS: Basal serum levels of DHEA, DS, androsternedione (A), testosterone (T) and dihydrotestosterone (DHT) were at or below the lower range of young adult levels. In both sexes, a 100 mg daily dose of DHEA restored serum DHEA levels to those of young adults and serum DS to levels at or slightly above the young adult range. Serum cortisol levels were unaltered, consequently the DS/cortisol ratio was increased to pubertal (10:1) levels. In women, but not in men, serum A, T and DHT were increased to levels above gender-specific young adult ranges. Basal SHBG levels were in the normal range for men and elevated in women, of whom 7 of 8 were on oestrogen replacement therapy. While on DHEA, serum SHBG levels declined with a greater (P < 0.02) response in women (-40 +/- 8%; P = 0.002) than in men (-5 +/- 4%; P = 0.02). Relative to baseline, DHEA administration resulted in an elevation of serum IGF-I levels in men (16 +/- 6%, P = 0.04) and in women (31 +/- 12%, P = 0.02). Serum levels of IGFBP-1 and IGFBP-3 were unaltered but GHBP levels declined in women (28 +/- 6%; P = 0.02) not in men. In men, but not in women, fat body mass decreased 1.0 +/- 0.4 kg (6.1 +/- 2.6%, P = 0.02) and knee muscle strength 15.0 +/- 3.3% (P = 0.02) as well as lumbar back strength 13.9 +/- 5.4% (P = 0.01) increased. In women, but not in men, an increase in total body mass of 1.4 +/- 0.4 kg (2.1 +/- 0.7%; P = 0.02) was noted. Neither gender had changes in basal metabolic rate, bone mineral density, urinary pyridinoline cross-links, fasting insulin, glucose, cortisol levels or lipid profiles. No significant adverse effects were observed. CONCLUSIONS: A daily oral 100 mg dose of DHEA for 6 months resulted in elevation of circulating DHEA and DS concentrations and the DS/cortisol ratio. Biotransformation to potent androgens near and slightly above the range of their younger counterparts occurred in women with no detectable change in men. Given this hormonal milieu, an increase in serum IGF-I levels was observed in both genders but dimorphic responses were evident in fat body mass and muscle strength in favour of men. These differences in response to DHEA administration may reflect a gender specific response to DHEA and/or the presence of confounding factor(s) in women such as oestrogen replacement therapy.  相似文献   

3.
PURPOSE: Finasteride therapy for benign prostatic hyperplasia (BPH) results in a marked lowering of serum prostate specific antigen (PSA) levels. However, little is known about the effect of finasteride on unbound or free serum levels of PSA. Such information would be important since percent free PSA may substantially improve the cancer specificity of PSA testing. Thus, we prospectively studied the effect of finasteride therapy on total and free serum PSA levels. MATERIALS AND METHODS: In a randomized, placebo controlled, double-blind trial 40 men with histologically confirmed BPH (age range 52 to 78 years) were treated with either 5 mg. finasteride daily (26 patients) for 9 months or placebo (14) for 6 months. Prostate volume was assessed by transrectal ultrasound. Serum levels of free and total PSA were measured from archived serum samples stored at -70C at baseline and for as long as 9 months of treatment. RESULTS: In the finasteride group mean total PSA levels declined from 3.0 ng./ml. at baseline to 1.5 ng./ml. after 6 months of treatment (50% decrease, p <0.01). In the placebo group, with similar baseline levels, no significant change was observed. PSA density declined significantly in finasteride treated men (p <0.01) but not in men receiving placebo. The mean percent free PSA (13 to 17% at baseline) was not altered significantly by finasteride or placebo. CONCLUSIONS: Total PSA serum levels decreased by an average of 50% during finasteride therapy but percent free PSA did not change significantly. This information is potentially useful in the interpretation of PSA data used for early detection of prostate cancer in men receiving finasteride. However, further studies are required to demonstrate the use of percent free PSA to detect the development of cancer.  相似文献   

4.
PURPOSE: To identify prognostic variables that predict for improved biochemical and local control outcome in patients with localized prostatic cancer treated with neoadjuvant androgen deprivation (NAAD) and three-dimensional conformal radiotherapy (3D-CRT). MATERIALS AND METHODS: Between 1989 and 1995, 213 patients with localized prostate cancer were treated with a 3-month course of NAAD that consisted of leuprolide acetate and flutamide before 3D-CRT. The purpose of NAAD in these patients was to reduce the preradiotherapy target volume so as to decrease the dose delivered to adjacent normal tissues and thereby minimize the risk of morbidity from high-dose radiotherapy. The median pretreatment prostate-specific antigen (PSA) level was 15.3 ng/mL (range, 1 to 560 ng/mL). The median 3D-CRT dose was 75.6 Gy (range, 64.8 to 81 Gy), and the median follow-up time was 3 years (range, 1 to 7 years). RESULTS: The significant predictors for improved outcome as identified in a multivariate analysis included pretreatment PSA level < or = 10.0 ng/mL(P < .00), NAAD-induced preradiotherapy PSA nadir < or = 0.5 ng/mL (P < .001), and clinical stage < or = T2c (P < .04). The 5-year PSA relapse-free survival rates were 93%, 60%, and 40% for patients with pretreatment PSA levels < or = 10 ng/mL, 10 to 20 ng/mL, and greater than 20 ng/mL, respectively (P < .001). Patients with preradiotherapy nadir levels < or = 0.5 ng/mL after 3 months of NAAD experienced a 5-year PSA relapse-free survival rate of 74%, as compared with 40% for patients with higher nadir levels (P < .001). The incidence of a positive biopsy among 34 patients pretreated with androgen ablation was 12%, as compared with 39% for 117 patients treated with 3D-CRT alone who underwent a biopsy (P < .001). CONCLUSION: For patients treated with NAAD and high-dose 3D-CRT, pretreatment PSA, preradiotherapy PSA nadir response, and clinical stage are important predictors of biochemical outcome. Patients with NAAD-induced PSA nadir levels greater than 0.5 ng/mL before radiotherapy are more likely to develop biochemical failure and may benefit from more aggressive therapies.  相似文献   

5.
The present data show a dramatic decline in the circulating levels of dehydroepiandrosterone (DHEA), DHEA-sulfate (DHEA-S), androst-5-ene-3 beta,17 beta-diol (5-diol), 5-diol-sulfate, 5-diol-fatty acid esters, and androstenedione in both men and women between the ages of 20-80 yr. In the 50- to 60-yr-old group, serum DHEA decreased by 74% and 70% from its peak values in 20- to 30-yr-old men and women, respectively. the serum concentrations of the conjugated metabolites of dihydrotestosterone (DHT), namely androsterone (ADT)-G, androstane-3 alpha,17 beta-diol (3 alpha-diol-G), androstane-3 beta,17 beta-diol (3 beta-diol-G), and ADT-sulfate are the most reliable parameters of the total androgen pool in both men and women, whereas serum testosterone and DHT can be used as markers of testicular secretion in men and interstitial ovarian secretion in women. The serum concentration of these various conjugated androgen metabolites decreased by 40.8% to 72.8% between the 20- to 30-yr-old and 70- to 80-yr-old age groups in men and women, respectively, thus suggesting a parallel decrease in the total androgen pool with age. As estimated by measurement of the circulating levels of these conjugated metabolites of DHT, it is noteworthy that women produce approximately 66% of the total androgens found in men. In women, most of these androgens originate from the transformation of DHEA and DHEA-S into testosterone and DHT in peripheral intracrine tissues, whereas in men the testes and DHEA and DHEA-S provide approximately equal amounts of androgens at the age of 50-60 yr. An additional potentially highly significant observation is that the majority of the marked decline in circulating adrenal C19 steroids and their resulting androgen metabolites takes place between the age groups of 20- to 30-yr olds and 50- to 60-yr-olds, with smaller changes are observed after the age of 60 yr.  相似文献   

6.
OBJECTIVES: To affirm the feasibility of using intermittent androgen suppression in patients with hormone-naive prostate cancer. METHODS: Leuprolide and flutamide were administered for 9 to 12 months and then discontinued until prostate-specific antigen (PSA) levels reached a threshold value determined by the baseline PSA value. This constituted one cycle of treatment. Androgen suppression was then administered intermittently as described until there was evidence of androgen independence. RESULTS: Twenty-two patients with PSA failure after primary therapy with surgery and/or radiation and untreated early or Stage D2 disease were treated. Twenty-one patients completed androgen suppression during cycle 1, with a median time to PSA nadir of 3.5 months (range, 2 to 12). Fifteen patients completed cycle 1 with a median time off treatment of 6 months (range, 2 to 19) or 38% (range, 17% to 64%) of a treatment cycle. Six patients continued off treatment during cycle 1 for 1+ to 31+ months. During cycle 2, 12 patients achieved a PSA nadir in a median time of 3.5 months. Two patients completed cycle 2 with a median time off treatment of 10 months (51%). Median follow-up for all patients is 26 months (range, 10 to 51). While off treatment, all patients reported a reduction of symptoms associated with androgen suppression. CONCLUSIONS: Intermittent androgen suppression is a feasible alternative to continuous androgen suppression for treatment of prostate cancer, and quality of life is improved while off treatment.  相似文献   

7.
LNCaP is an androgen-sensitive human prostatic cancer cell line. The effect of androgen on these cells is characterized by a bell-shaped growth response and a dose-dependent induction of prostate-specific antigen (PSA) production. The present study was carried out to gain further insight into the effect of androgen on LNCaP. Cells were cultured in phenol red-free RPMI-1640 supplemented with 10% charcoal-stripped fetal bovine serum, with concentrations of dihydrotestosterone (DHT) ranging from 0-10(-7) M, in a 4-day culture system. A bell-shaped growth response was reproduced with a peak level of cell count at 10(-10) M DHT. PSA secretion from these cells did not increase significantly until the DHT level in the medium reached 10(-9) M. A progressive increase in PSA secretion was observed at higher DHT concentrations accompanied with a progressive decline in cellular proliferation. The results of immunocytochemical analysis of PSA localization indicated that the proportion of cells with positive staining for PSA also increased with increasing concentrations of DHT. Analysis of androgen receptors, as determined by both immunocytochemistry and Western blot analysis, showed a decline in nuclear androgen receptor at low concentrations of DHT and an increase in the amount of receptor protein at high concentrations. These results indicated that the androgen-induced bell-shaped growth response in LNCaP cells represented the manifestation of two different cellular events in dose-related manner: cellular proliferation at low DHT concentrations and increased production of PSA at high DHT concentrations.  相似文献   

8.
Finasteride, a 5 alpha-reductase inhibitor, decreases prostate size and improves symptoms in men with benign prostatic hyperplasia. However, little is known about prostate histopathology in men taking finasteride. To determine the mechanism by which finasteride reduces prostate size, tissue was collected at the time of prostatectomy from men taking either no medication (n = 10) or 5 mg finasteride daily for 6-18 days (n = 6; group 1), 23-73 days (n = 5; group 2), or 3 months to 4 yr (n = 5; group 3). To assess whether finasteride causes epithelial atrophy, morphometric measurement of epithelial cell and duct width was used. The mean epithelial cell width in control prostates (mean +/- SEM, 21 +/- 0.7 microns) decreased with duration of treatment to 19 +/- 1 microns in group 1, 15 +/- 2 microns in group 2, and 8 +/- 0.3 microns in group 3. Mean duct width decreased from 135 +/- 6 microns in the control prostates to 128 +/- 10 microns in group 1, 103 +/- 3 microns in group 2, and 63 +/- 6 microns in group 3. To assess whether prostate cell death was occurring, sections were in situ end labeled for DNA breaks and immunostained for tissue transglutaminase (tTG), a marker of apoptosis (programmed cell death). The percentage of epithelial cells staining for DNA breaks was 0.4 +/- 0.2 in control prostates, 2.8 +/- 0.9 in group 1, 1.7 +/- 0.5 in group 2, and 0.7 +/- 0.3 microns in group 3. Anti-tTG staining of epithelial cells was graded on a scale of 0-4. In control prostates, 3 +/- 1% of the ducts were grade 3 or 4 (> 50% of epithelial cells staining). In finasteride-treated prostates, 2 +/- 2% of the prostates in group 1, 13 +/- 4% of the prostates in group 2, and 0.5 +/- 0.5% of the prostates in group 3 were grade 3-4. These results indicate that a progressive decrease in epithelial cell size and function occurs during the first several months in the prostates of men treated with finasteride. The staining for DNA breaks and the tTG staining also indicate that an increased rate of apoptosis is occurring transiently in these prostates. We conclude that finasteride causes prostate involution through a combination of atrophy and cell death.  相似文献   

9.
OBJECTIVES: To compare the long-term effects of finasteride (5 mg/day) and placebo in patients with moderate symptoms of benign prostatic hyperplasia (BPH). METHODS: Patients aged 50 to 75 years, with at least two urinary symptoms indicating moderate BPH, and an enlarged prostate, were followed in a 2-year double-blind, randomized, placebo-controlled multicenter study. The effects of finasteride versus placebo were assessed by total symptom score (modified Boyarsky), obstructive symptom score, maximal urinary flow rate, prostate volume, and urologic end points (acute urinary retention, BPH-related surgical intervention). RESULTS: Of the 3270 men enrolled, 3168 contributed data to the safety analysis, and 2902 to the efficacy evaluation. Significantly greater improvement with finasteride compared to placebo was observed at 12 and 24 months for total symptom score (mean -2.9 versus -1.9 at 12 months, P < or =0.001; -3.2 versus -1.5 at 24 months, P < or =0.001), obstructive symptom score (mean -1.9 versus -1.3 at 12 months, P < or =0.001; -2.1 versus -1.1 at 24 months, P < or =0.001), maximal urinary flow rate (mean +1.2 versus +0.6 mL/s at 12 months, P = 0.010; +1.5 versus +0.7 mL/s at 24 months, P = 0.002), and prostate volume (mean -14.2 versus +5.4% at 12 months, P < or =0.01; -15.3 versus +8.9% at 24 months, P < or =0.001). Greater improvements in placebo-adjusted total symptom score occurred in men with large prostates than in men with small prostates (mean -2.4 versus -1.1 at 12 months; -3.2 versus -1.3 at 24 months, placebo-adjusted data, P = 0.053). Fifteen of 1450 men (1.0%) in the finasteride group experienced an acute urinary retention event, compared with 37 of 1452 (2.5%) in the placebo group, and the corresponding figures for surgery were 51 of 1450 (3.5%) and 86 of 1452 (5.9%), respectively. The hazard rate for occurrence, computed using the log-rank statistic, decreased by 57% for acute urinary retention and by 40% for surgery accompanied by finasteride therapy compared to placebo. CONCLUSIONS: Finasteride causes long-term symptomatic improvement and reduces the risk of acute urinary retention or surgery. Men with enlarged prostates benefit most from finasteride treatment.  相似文献   

10.
The 5alpha-reductase inhibitor finasteride blocks the conversion of testosterone to dihydrotestosterone (DHT), the androgen responsible for male pattern hair loss (androgenetic alopecia) in genetically predisposed men. Results of phase III clinical studies in 1879 men have shown that oral finasteride 1 mg/day promotes hair growth and prevents further hair loss in a significant proportion of men with male pattern hair loss. Evidence suggests that the improvement in hair count reported after 1 year is maintained during 2 years' treatment. In men with vertex hair loss, global photographs showed improvement in hair growth in 48% of finasteride recipients at 1 year and in 66% at 2 years compared with 7% of placebo recipients at each time point. Furthermore, hair counts in these men showed that 83% of finasteride versus 28% of placebo recipients had no further hair loss compared with baseline after 2 years. The clinical efficacy of oral finasteride has not yet been compared with that of topical minoxidil, the only other drug used clinically in patients with male pattern hair loss. Therapeutic dosages of finasteride are generally well tolerated. In phase III studies, 7.7% of patients receiving finasteride 1 mg/day compared with 7.0% of those receiving placebo reported treatment-related adverse events. The overall incidence of sexual function disorders, comprising decreased libido, ejaculation disorder and erectile dysfunction, was significantly greater in finasteride than placebo recipients (3.8 vs 2.1%). All sexual adverse events were reversed on discontinuation of therapy and many resolved in patients who continued therapy. No other drug-related events were reported with an incidence > or =1% in patients receiving finasteride. Most events were of mild to moderate severity. Oral finasteride is contraindicated in pregnant women because of the risk of hypospadias in male fetuses. CONCLUSIONS: Oral finasteride promotes scalp hair growth and prevents further hair loss in a significant proportion of men with male pattern hair loss. With its generally good tolerability profile, finasteride is a new approach to the management of this condition, for which treatment options are few. Its role relative to topical minoxidil has yet to be determined.  相似文献   

11.
OBJECTIVE: To develop a pharmacokinetic-pharmacodynamic model that characterizes the conversion of testosterone to dihydrotestosterone (DHT) by 5 alpha-reductase types 1 and 2 and the irreversible inhibition of 5 alpha-reductase by finasteride, a 5 alpha-reductase type 2 inhibitor and by GI198745 (dutasteride), a potent and specific dual 5 alpha-reductase inhibitor. METHODS: Healthy men (n = 48) received doses of 0.1 to 40 mg GI198745 (n = 4 subjects per dose), 5 mg finasteride (n = 8), or placebo (n = 8) in a parallel-group study. Plasma concentrations of GI198745, finasteride, and DHT were measured frequently up to 8 weeks after dosing. Models were fitted with mixed-effects modeling with the NONMEM program. RESULTS: The pharmacodynamics were well described with a model that accounted for the rates of DHT formation and elimination, 5 alpha-reductase turnover, relative capacity of the 2 5 alpha-reductase isozymes, and the rates of irreversible inhibition of one (finasteride) or both (GI198745) types of 5 alpha-reductase. The model indicated that type 2 5 alpha-reductase contributed approximately 80% of plasma DHT. GI198745 was about 3-fold more potent than finasteride on 5 alpha-reductase type 2. Nearly full blockade of both isozymes was achieved at doses of 10 mg or more GI198745, although the potency of this agent on 5 alpha-reductase type 1 was less than on type 2. CONCLUSIONS: A physiologically based model for the turnover and irreversible inhibition of 5 alpha-reductase and for formation and elimination of DHT described the data well. This model helps explain differences in the rates of onset and offset of effect and offers a way to determine the relative potency of the irreversible 5 alpha-reductase inhibitors.  相似文献   

12.
The prevalence of BPH is high in elderly men with more than 60% of patients over the age of 60 experiencing some form of prostatism. Balancing the superior benefit of TUR/P are the small but significant risks and complications of surgery and the high cost of the procedure. The WHO guidelines recommend finasteride or alpha-blockers as treatment options for men with bothersome symptoms. Finasteride therapy reduces the volume of the hyperplastic prostate gland by more than 20%, improves the urinary flow rate and the symptoms associated with bladder outlet obstruction. Although statistically significant, results obtained with finasteride are just slightly better than placebo and TUR/P still offers the greatest improvement of symptoms. Finasteride is well tolerated and adverse events are rare. However, it decreases serum PSA (prostate specific antigen) by 50%, suggesting careful monitoring and exclusion of prostate cancer before initiation and during therapy. Current research is focusing on developing new 5-alpha-reductase inhibitors (type I and II) using polyunsaturated fatty acids and nonsteroidal inhibitors. Given the multifactorial nature of BPH, further clinical trials combining 5-alpha-reductors inhibitors and 5-alpha-receptor blockers are still needed.  相似文献   

13.
24 consecutive AIDS patients with wasting, and who had never received anabolic therapies, were evaluated to determine their profile of sex hormones and whether transformation of testosterone (T) to the nuclear androgen, dihydrotestosterone (DHT), was impaired. Eleven (46%) patients had normal testosterone and DHT (group I), 10 (42%) had normal testosterone but low DHT (group II), and 3 (12%) had low testosterone and low DHT (group III). Age, prior opportunistic complications, symptoms, serum albumin, hemoglobin levels, and CD4 lymphocyte counts were similar in the groups. DHT was significantly lower (22.2 +/- 6.8 microg/dl) in group II compared with group I (50.8 +/- 15.3 microg/dl). The ratio of T/DHT, a measure of the conversion of testosterone to DHT, in group I was 15.1 +/- 3.5, which was within the range for eugonadal young men. In group II, the ratio was 22.3 +/- 1.5, indicating a defect in generation of DHT. Patients in group II had lost 9.2 +/- 3.5 kg compared with 5.6 +/- 2.6 kg in group I (p = .015). Thus, a syndrome of low DHT with normal testosterone was associated with significantly greater weight loss than in patients with normal testosterone and DHT. Further studies are needed to clarify whether low DHT is a result of AIDS wasting or is causally related to weight loss and whether androgen therapy in the form of DHT could reverse some of the metabolic changes associated with AIDS wasting.  相似文献   

14.
BACKGROUND: The aim of this work was to evaluate the efficacy of two new antiandrogen drugs, finasteride and flutamide, in 80 hirsute patients: 44 with Polycystic Ovary Syndrome (PCOS) and 36 with Idiopathic Hirsutism (IH). METHODS: The study was conducted in a randomized way and randomization was carried out according to hospitalization. Before and after the treatment, all of the patients underwent hematochemical tests, hormone assays and assessment of hirsutism with the Ferriman Gallway score (F.G. score) and with measurement of the hair diameter in four different body areas. Finasteride was administered per os to 40 women at the dose of 5 mg/die; flutamide per os to 40 women at the dose of 250 mg twice daily. Both drugs were employed for 6 consecutive months. RESULTS: Both finasteride and flutamide significantly reduced the F.G. score and hair diameter. CONCLUSIONS: Abdominal hairs were more sensitive to the therapy.  相似文献   

15.
PNU 157706 is a novel dual inhibitor of 5alpha-reductase (5alpha-R), the enzyme responsible for the conversion of testosterone (T) to 5alpha-dihydrotestosterone (DHT). Tested on a crude preparation of human or rat prostatic 5alpha-R, PNU 157706 caused enzyme inhibition with IC50 values of 20 and 34 nM, respectively, compared to the values of 32 and 58 nM shown by finasteride. Furthermore, PNU 157706 was highly potent in inhibiting human recombinant 5alpha-R type I and II isozymes, showing IC50 values of 3.9 and 1.8 nM and, therefore, it was several folds more potent than finasteride (IC50 values of 313 and 11.3 nM), particularly on the type I isozyme. PNU 157706 was shown to have no binding affinity for the rat prostate androgen receptor (RBA 0.009% that of DHT). In adult male rats, a single oral dose of 10 mg/kg of PNU 157706 caused a marked and longer lasting reduction of prostatic DHT than did finasteride (at 24 h inhibition by 89 and 47%, respectively). In prepubertal, T- or DHT-implanted castrated rats, PNU 157706, given orally for 7 days at the dose of 10 mg/kg/day, markedly reduced ventral prostate weight in T- but not in DHT-implanted animals, thus showing to be devoid of any anti-androgen activity. In adult rats treated orally for 28 days, PNU 157706 resulted markedly more potent (16-fold) than finasteride in reducing prostate weight, the ED50 values being 0.12 and 1.9 mg/kg/day, respectively. These results indicate that PNU 157706 is a promising, potent inhibitor of both type II and I human 5alpha-R with a very marked antiprostatic effect in the rat.  相似文献   

16.
In order to assess the relative roles of the androgenic and/or estrogenic components in the stimulatory effect of dehydroepiandrosterone (DHEA) on bone mineral content (BMC) and density (BMD), ovariectomized (OVX) female rats received DHEA administered alone or in combination with the antiandrogen flutamide (FLU) or the antiestrogen EM-800 for 12 months. We also evaluated, for comparison, the effect of estradiol (E2) and dihydrotestosterone (DHT) constantly released by Silastic implants as well as medroxyprogesterone acetate (MPA) released from poly(lactide-co-glycolide) microspheres. Femoral BMD was decreased by 11% 1 year after OVX, but treatment of OVX animals with DHEA increased BMD to a value 8% above that of intact animals. The administration of FLU reversed by 76% the stimulatory effect of DHEA on femoral BMD and completely prevented the stimulatory effect of DHEA on total body and lumbar spine BMD. Similar results were obtained for BMC. On the other hand, treatment with the antiestrogen EM-800 did not reduce the action of DHEA on BMD or BMC. At the doses used, MPA, E2 and DHT increased femoral BMD, but to a lesser degree than observed with DHEA. Bone histomorphometry measurements were also performed. While DHEA treatment partially reversed the marked inhibitory effect of OVX on the tibial trabecular bone volume, the administration of FLU inhibited by 51% (P < 0.01) the stimulatory effect of DHEA on this parameter. The addition of EM-800 to DHEA, on the other hand, increased trabecular bone volume to a value similar to that of intact controls. DHEA administration markedly increased trabecular number while causing a marked decrease in the intertrabecular area. The above stimulatory effect of DHEA on trabecular number was reversed by 54% (P < 0.01) by the administration of FLU, which also reversed by 29% the decrease in intertrabecular area caused by DHEA administration. On the other hand, the addition of EM-800, while further decreasing the intertrabecular space achieved by DHEA treatment, also led to a further increase in trabecular number to a value not significantly different from that of intact control animals, suggesting an additional effect of EM-800 over that achieved by DHEA. Treatment with DHEA caused a 4-fold stimulation of serum alkaline phosphatase, a marker of bone formation, while the urinary excretion of hydroxyproline, a marker of bone resorption, was decreased by DHEA treatment. Treatment with DHEA and DHEA + EM-800 decreased serum cholesterol levels by 22 and 65% respectively, while the other treatments had no significant effect on this parameter. The present data indicate that the potent stimulatory effect of DHEA on bone in the rat is mainly due to the local formation of androgens in bone cells and their intracrine action in osteoblasts.  相似文献   

17.
The effect of testosterone (T) replacement on changes in mood was studied for 60 days in 51 hypogonadal men. All patients were withdrawn from their prior T replacement for at least 6 weeks before enrollment. Of these patients, 18 received T enanthate 200 mg im every 20 days, 16 received sublingual T cyclodextrin (SLT) at a dose of 2.5 mg three times daily, and 17 received SLT at a dose of 5.0 mg three times daily. The total treatment period was 60 days. The patients were asked to respond to a questionnaire on 7 consecutive days before the start of treatment and on 7 consecutive days before their visits to the clinic on days 21, 41, and 60 of treatment. The following mood parameters were assessed using a 7-point Likert rating scale: angry, alert, irritable, full of pep (energy), sad/blue, tired, friendly, nervous, and well/good. When compared with the baseline period, T replacement led to significant decreases in anger (P = 0.0045), irritability (P = 0.0009), sadness (P = 0.0033), tiredness (P = 0.0035), and nervousness (P = 0.0291), and significant improvement in energy level (P = 0.0020), friendliness (P = 0.0072), and sense of well-being (P = 0.024) in all subjects as a group. Analyses of the area under the curve (AUC) of baseline serum T levels before T replacement showed significant positive correlations between serum T (AUC) and friendliness (r = 0.29, P < 0.05) and sense of well-being (r = 0.27, P < 0.05), and significant negative correlations with nervousness (r = -0.27, P < 0.05), irritability (r = -0.29, P < 0.05) and tiredness (r = -0.28, P < 0.05). Similar correlations were found between serum dihydrotestosterone (DHT) and some of the mood parameters. After T replacement in the hypogonadal men, these correlations between AUC of serum T levels and the positive and negative mood scores disappeared. These results were corroborated in a subsequent study in which 30 hypogonadal men were supplemented with SLT 5 mg three times daily for 6 months. The patients were less nervous (P = 0.0025) and more alert (P = 0.0004), friendly (P = 0.042), and energetic (P = 0.0001) during the 6-month treatment period compared with baseline. We conclude that T replacement therapy in hypogonadal men improved their positive mood parameters, such as energy, well/good feelings, and friendliness and decreased negative mood parameters including anger, nervousness, and irritability, and direct correlations between serum T and DHT with mood scores were only observed in the baseline period when serum androgen levels were below the normal range. The latter observation suggests that once a minimally adequate serum T/DHT level was achieved by T replacement therapy, further increases in serum T/DHT levels did not further contribute to the improvement in mood variables.  相似文献   

18.
The biological effects of testosterone (T) may be mediated directly by T or indirectly by its metabolites, dihydrotestosterone (DHT) and estradiol. The present study examined whether the metabolism of T is involved in the regulation of GnRH-induced Ca2+ signaling at the pituitary. In gonadotrophs from castrated rats, a significantly greater percentage of gonadotrophs demonstrated oscillatory Ca2+ responses to 100 nM GnRH than cells from intact rats (72% vs. 24%; P < 0.05). This increase was prevented by the administration of T propionate (0.1 mg/kg x day), DHT benzoate (2 mg/kg x day,), estradiol benzoate (EB; 5 microg/kg x day), or the combination of the above doses of DHT benzoate and EB. In all cases the proportion of gonadotrophs from the steroid-treated rats having oscillatory Ca2+ responses to 100 nM GnRH was between 21-25% (P > 0.05, compared with intact rats). To assess the importance of T metabolism, intact male rats were treated with the aromatase inhibitor letrozole (1 mg/kg x day), the 5alpha-reductase inhibitor finasteride (50 mg/kg x day), or their respective vehicles for 7 days. Letrozole had no effect on GnRH-induced Ca2+ signals, serum LH concentrations, or ventral prostate or testes weight. Finasteride treatment, however, mimicked the effects of castration, with significantly more gonadotrophs exhibiting Ca2+ oscillations in response to 100 nM GnRH than gonadotrophs from the vehicle-treated group (71% vs. 20% respectively; P < 0.05). Finasteride also caused a significant (P < 0.05) decrease in prostatic weight and DHT concentration, but had no significant effect on either prostatic T or serum LH concentrations. These findings suggest that in the intact male rat, the effects of T on GnRH-induced Ca2+ signaling are preferentially mediated via DHT. The results of this study also show that in the absence of androgens, estradiol may regulate GnRH-induced Ca2+ signaling in the male rat pituitary.  相似文献   

19.
BACKGROUND: Men with benign prostatic hyperplasia can be treated with alpha 1-adrenergic-antagonist drugs that relax prostatic smooth muscle or with drugs that inhibit 5 alpha-reductase and therefore reduce tissue androgen concentrations. However, the effects of the two types of drugs have not been compared. METHODS: We compared the safety and efficacy of placebo, terazosin (10 mg daily), finasteride (5 mg daily), and the combination of both drugs in 1229 men with benign prostatic hyperplasia. American Urological Association symptom scores and peak urinary-flow rates were determined at base line and periodically for one year. RESULTS: The mean changes from base line in the symptom scores in the placebo, finasteride, terazosin, and combination-therapy groups at one year were decreases of 2.6, 3.2, 6.1, and 6.2 points, respectively (P<0.001 for the comparisons of both terazosin and combination therapy with finasteride and with placebo). The mean changes at one year in the peak urinary-flow rates were increases of 1.4, 1.6, 2.7, and 3.2 ml per second, respectively (P<0.001 for the comparisons of both terazosin and combination therapy with finasteride and with placebo). Finasteride had no more effect on either measure than placebo. In the placebo group, 1.6 percent of the men discontinued the study because of adverse effects, as did 4.8 to 7.8 percent of the men in the other three groups. CONCLUSIONS: In men with benign prostatic hyperplasia, terazosin was effective therapy, whereas finasteride was not, and the combination of terazosin and finasteride was no more effective than terazosin alone.  相似文献   

20.
BACKGROUND: A prospective Phase II clinical trial was conducted to assess the clinical activity of a pharmacokinetically guided suramin regimen in patients who had documented progression of metastatic prostate cancer after hydrocortisone plus antecedent or simultaneous withdrawal of flutamide. METHODS: Fifty-four patients whose disease had progressed after castration and flutamide administration were enrolled on this trial. The study was divided into two parts. Initially, 52 patients received hydrocortisone (30 mg/day) and for those patients receiving flutamide, at study entry (34 patients) flutamide was simultaneously discontinued. Forty-three patients whose disease progressed on hydrocortisone received suramin for 6-8 weeks. Six patients who progressed on hydrocortisone became ineligible for suramin due to clinical deterioration, four patients are still responding to hydrocortisone at more than 1 year, and one patient elected to postpone initiation of suramin. Suramin was given as intermittent infusions at fixed doses on days 1-5 and thereafter dosing was guided by adaptive control with feedback to maintain plasma suramin concentrations between 300-175 micrograms/ml. Antitumor activity was assessed by prostate specific antigen (PSA) decline and soft-tissue disease response. RESULTS: Ten patients (19%; 95% CI, 9.6%-32.5%) responded to hydrocortisone therapy with either a 50% or greater PSA decline for at least 4 weeks (9 patients) and/or a partial response of measurable soft-tissue disease (2 patients). Five of these patients (10%) demonstrated a 80% or greater PSA decline. All responders to hydrocortisone had simultaneous flutamide withdrawal, and had been receiving flutamide as part of initial combined androgen blockade. Seven of 37 evaluable patients (19%; 95% CI, 8.0%-35.2%) responded to suramin with a 50% or greater decline in PSA for 4 weeks or longer. One patient (3%) had a 80% or greater decline in PSA. There were no soft-tissue disease responses to suramin. The median time to progression was 1.9 months for hydrocortisone therapy and 2.6 months for suramin therapy. The median survival for all patients was 14.6 months. CONCLUSION: Suramin has antitumor activity in metastatic prostate carcinoma independent of the therapeutic effect of hydrocortisone administration or flutamide withdrawal. The role of prior flutamide withdrawal and hydrocortisone replacement should be taken into account in future studies of suramin.  相似文献   

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