Administration Of Antiandrogens Research Articles

Sexual differentiation in three unconventional mammals: Spotted hyenas, elephants and tammar wallabies

The present review explores sexual differentiation in three non-conventional species: the spotted hyena, the elephant and the tammar wallaby, selected because of the natural challenges they present for contemporary understanding of sexual differentiation. According to the prevailing view of mammalian sexual differentiation, originally proposed by Alfred Jost, secretion of androgen and anti-Mullerian hormone (AMH) by the fetal testes during critical stages of development accounts for the full range of sexually dimorphic urogenital traits observed at birth. Jost's concept was subsequently expanded to encompass sexual differentiation of the brain and behavior. Although the central focus of this review involves urogenital development, we assume that the novel mechanisms described in this article have potentially significant implications for sexual differentiation of brain and behavior, a transposition with precedent in the history of this field. Contrary to the “specific” requirements of Jost's formulation, female spotted hyenas and elephants initially develop male-type external genitalia prior to gonadal differentiation. In addition, the administration of anti-androgens to pregnant female spotted hyenas does not prevent the formation of a scrotum, pseudoscrotum, penis or penile clitoris in the offspring of treated females, although it is not yet clear whether the creation of masculine genitalia involves other steroids or whether there is a genetic mechanism bypassing a hormonal mediator. Wallabies, where sexual differentiation occurs in the pouch after birth, provide the most conclusive evidence for direct genetic control of sexual dimorphism, with the scrotum developing only in males and the pouch and mammary glands only in females, before differentiation of the gonads. The development of the pouch and mammary gland in females and the scrotum in males is controlled by genes on the X chromosome. In keeping with the “expanded” version of Jost's formulation, secretion of androgens by the fetal testes provides the best current account of a broad array of sex differences in reproductive morphology and endocrinology of the spotted hyena, and androgens are essential for development of the prostate and penis of the wallaby. But the essential circulating androgen in the male wallaby is 5α androstanediol, locally converted in target tissues to DHT, while in the pregnant female hyena, androstenedione, secreted by the maternal ovary, is converted by the placenta to testosterone (and estradiol) and transferred to the developing fetus. Testicular testosterone certainly seems to be responsible for the behavioral phenomenon of musth in male elephants. Both spotted hyenas and elephants display matrilineal social organization, and, in both species, female genital morphology requires feminine cooperation for successful copulation. We conclude that not all aspects of sexual differentiation have been delegated to testicular hormones in these mammals. In addition, we suggest that research on urogenital development in these non-traditional species directs attention to processes that may well be operating during the sexual differentiation of morphology and behavior in more common laboratory mammals, albeit in less dramatic fashion.

Mechanisms of endocrine therapy-responsive and -unresponsive prostate tumours

Several options for the endocrine treatment of non-organ-confined prostate cancer are available. They include surgical or medical removal of androgenic hormones or administration of non-steroidal anti-androgens. However, tumour progression after a period of remission of the disease inevitably occurs in virtually all patients. The androgen receptor (AR) is, in various tumour models, implicated in the development of therapy resistance but molecular mechanisms that by-pass the receptor have also been described. Adaptation mechanisms relevant to tumour recurrence include up-regulation of AR mRNA and protein, overexpression of AR coactivators, increased activation of mutated receptors by steroids and anti-androgens, and ligand-independent activation. For research studies, sublines that respond to but do not depend on androgen for their proliferation were generated. Coactivators SRC-1, TIF-2, RAC3, p300, CBP, Tip60, and gelsolin are highly expressed in endocrine therapy-resistant prostate cancer. AR point mutations are increasingly detected in relapsed cancers and contribute to the failure of endocrine therapy in a subgroup of patients. Ligand-independent activation of the AR by HER-2/neu and interleukin-6 is associated with activation of the signalling pathway of mitogen-activated protein kinase. Increased activity of intracellular kinases may affect cellular events in both an AR-dependent and -independent manner. Mitogen-activated protein kinases are strongly phosphorylated in endocrine therapy-resistant prostate tumours. Similarly, activation of the AR by phosphorylated protein kinase B, Akt, has also been reported in prostate cancer. Activation of the Akt pathway contributes to increased survival of prostate tumour cells.

Gynecomastia Due to Hormone Therapy for Advanced Prostate Cancer: A Report of Ten Surgically Treated Cases and a Review of Treatment Options

Gynecomastia is an abnormal increase in the volume of the male breast that is generally considered to be due to an increased estrogen/androgen ratio. Pathological causes of gynecomastia include organic diseases and therapy, such as the administration of estrogens and antiandrogens, which alter the ratio of circulating hormones. Hormone therapy for prostate cancer is generally well tolerated but often accompanied by the occurrence of gynecomastia and breast pain or tenderness. The increased use of antiandrogens as monotherapy is leading to an increase in the number of patients affected by gynecomastia. Treatments are available to alleviate or prevent the development of gynecomastia, including medical treatment with antiestrogens and aromatase inhibitors. Alternatively, mastectomy with excision of the gland, liposuction or an association of the two techniques have proved to be effective. Radiation therapy may provide effective relief from the breast pain associated with gynecomastia. In this paper we show the good results of mastectomy performed with a lower semicircular periareolar incision in men suffering from gynecomastia due to antiandrogen therapy for inoperable prostate cancer. In addition, we present a review of the various techniques used for the treatment of gynecomastia. During the period from September 1998 to May 2001, 10 patients receiving hormone treatment for metastatic or inoperable prostatic cancer were selected for the study if they had breast pain and bilateral gynecomastia. Five of these patients had been offered prophylactic radiotherapy before treatment but refused, while the remaining five patients had refused radiotherapy after hormone treatment. These patients were therefore given the option of surgical treatment. Before surgery all patients underwent clinical and ultrasound examination of the breast. All surgical samples were examined histopathologically. During follow-up clinical examinations were carried out one week, one month, six months, one year and two years after surgery. The results were satisfactory in all patients especially from an aesthetic point of view. Moreover, breast pain disappeared about one week after surgery. After a follow-up of 6-36 months (average, 22.8 months) no recurrences were observed. Only a few immediate postoperative complications were recorded (hematoma in one case and seroma in another). Histological examination of the excised glands showed fibrosclerotic tissue and a small amount of fat. Surgical liposuction can be considered an effective treatment for gynecomastia, in particular in the very early stages because the breast becomes irreversibly fibrous as the disease progresses. This surgical technique is simple and effective and is therefore to be considered favorable, especially because of the very short hospitalization and the absence of complications.

An antigen capture assay for the measurement of serum clusterin concentrations

We have developed and validated a robust antigen capture assay for the measurement of serum clusterin. Increased clusterin expression, and alterations in serum clusterin levels have been associated with a number of disease states. In particular, clusterin has been shown to be associated with tissue regression and apoptosis in the rat ventral prostate in response to androgen ablation or administration of anti-androgens. The object of this study was to determine if changes in human serum clusterin can be used as a diagnostic or prognostic marker to monitor the response to hormonal therapy in patients with prostate cancer, and to determine if clusterin concentrations increase with the progression towards androgen independence. The antigen capture assay was used for an extensive analysis of human serum clusterin concentration in fasting males, and to determine if there is any relationship between clusterin and age or cholesterol levels. The average clusterin level in serum is 101±42 μg/ml ( n=96). There is no correlation to age or serum cholesterol levels. Analysis of serum clusterin levels in patients with newly diagnosed prostate cancer ( n=5), hormone responsive tumors ( n=5), and hormone refractory disease ( n=5), demonstrates that no significant changes in serum clusterin levels accompany the progression of prostatic disease, or response to hormone therapy.

Ultrastructural and Quantitative Immunohistochemical Changes Induced by Nonsteroid Antiandrogens on Pituitary Gonadotroph Population of Prepubertal Male Rats

Specific blockade of the androgen receptor by the nonsteroid antiandrogens flutamide and Casodex has proven to be a useful tool for studying androgens in vivo. The aim of the present study was to investigate the effect of antiandrogen administration at the pituitary level by evaluating the ultrastructural changes in gonadotrophs, in correlation with the quantitative immunohistochemical findings, and by comparing these alterations with the effect of androgen deprivation by castration either with or without subsequent androgen replacement. Male Sprague-Dawley rats (23 days old) were grouped as follows: (1) controls, (2) flutamide-injected (10 mg/rat/day), (3) Casodex-injected (10 mg/rat/day), (4) castrated, and (5) castrated plus androgen-replaced (dihydrotestosterone propionate; 40 µg/rat/day). Groups were sacrificed after 10 days of maintenance under each condition. Pituitaries were processed for both light and electron microscopy. Serial sections (4 µm) were obtained at different levels and immunostained by means of the primary murine monoclonal antibodies anti-FSH and anti-LH and a peroxidase-mediated EnVision System (Dako). Volume density, cell density and mean cell area were measured with an image analysis system (Imaging Technology, Software Optimas 5.2). The mean cell area (p < 0.001) and the volume density (p < 0.05) increased significantly in the flutamide- and Casodex-treated groups as well as the castrated group of FSH and LH cells. On the other hand, androgen replacement in the castrated rats, however, reduced in both parameters related to control animals. The cell density of FSH-secreting cells was increased (p < 0.05) in the Casodex and flutamide treatment as well as castrated group. The cell density of LH-secreting cells was augmented (p < 0.05) in the Casodex-treated group, while there was no increase in such parameter with flutamide and castration. The ultrastructure of all groups showed two types of gonadotrophs. Type I cells contained large (300–500 nm) and small (150–200 nm) secretory granules, while type II cells were smaller, and exhibited only small granules (100–200 nm). Flutamide-treated, Casodex-treated and castrated groups presented a decreased number of secretory granules with some exocytotic profiles, well-developed rough endoplasmic reticulum and an expanded Golgi complex of both types of cells. The gonadotrophs from the castrated group exhibited numerous mitochondria with electron-dense ring-shaped laminar figures, while in the castrated plus androgen-replaced rats only a few mitochondria had similar changes to those observed in castrated animals, as a possible residual alteration. Finally, the gonadotrophs from flutamide-treated rats showed mitochondrial alterations with clear areas and isolated electron-dense laminar figures. In summary, we conclude that lack of androgen reaction through the effects of nonsteroid antiandrogens and castration on prepubertal rats produced a hypertrophia-hyperplasia of the FSH cells, and hypertrophia of LH-secreting cells, with marked alterations at the ultrastructural level suggestive of a hyperstimulation stage.

NEW TREATMENTS OF HYPERANDROGENISM AND HIRSUTISM

Approximately 5% to 8% of the female population demonstrates some form of hirsutism, the presence of prominent facial and body hair caused by excessive androgen effect. Treatment methods are classified into three categories: (1) hormonal suppression consisting of medical therapy to decrease androgen production, (2) the administration of antiandrogens to block the androgen effect at the hair follicle, and (3) physical methods of hair removal. Most patients require a combination of medical and physical therapy.

Effects of Sex Steroid Deprivation/Administration on Hair Growth and Skin Sebum Production in Transsexual Males and Females

To investigate androgen effects on the skin pilosebaceous unit, we studied 21 male-to-female transsexuals and 17 female-to-male transsexuals receiving cross-sex hormones. At baseline and after 4, 8, and 12 months, hair growth was evaluated by the Ferriman-Gallwey score; acne by the Leeds classification; hair growth rate, density, and shaft diameter by image analysis; and sebum production by Sebutape. In males, estrogens and antiandrogens reduced plasma testosterone to below 1.0 nmol/L. Though all parameters of hair growth and sebum production declined, facial hair growth continued. After 4 months, the decrease in shaft diameter had reached its maximum and seemed inversely associated with changes in hair growth length and density. In females, testosterone increased hair growth rate and sebum production. After 12 months, hairs on the cheek and abdomen had not yet reached diameters found in males. 5α-Androstane-3α,17β-diol glucuronide levels were only weakly associated with hair growth and sebum production. In conclusion, administration of estrogens and antiandrogens affects length and diameter of hairs at different rates. In the virtual absence of androgens, hair growth continues but at a slower rate. In women, after 12 months of androgen administration, hair diameters have not reached values of adult men.

Effects of sex steroid deprivation/administration on hair growth and skin sebum production in transsexual males and females.

To investigate androgen effects on the skin pilosebaceous unit, we studied 21 male-to-female transsexuals and 17 female-to-male transsexuals receiving cross-sex hormones. At baseline and after 4, 8, and 12 months, hair growth was evaluated by the Ferriman-Gallwey score; acne by the Leeds classification; hair growth rate, density, and shaft diameter by image analysis; and sebum production by Sebutape. In males, estrogens and antiandrogens reduced plasma testosterone to below 1.0 nmol/L. Though all parameters of hair growth and sebum production declined, facial hair growth continued. After 4 months, the decrease in shaft diameter had reached its maximum and seemed inversely associated with changes in hair growth length and density. In females, testosterone increased hair growth rate and sebum production. After 12 months, hairs on the cheek and abdomen had not yet reached diameters found in males. 5alpha-Androstane-3alpha,17beta-diol glucuronide levels were only weakly associated with hair growth and sebum production. In conclusion, administration of estrogens and antiandrogens affects length and diameter of hairs at different rates. In the virtual absence of androgens, hair growth continues but at a slower rate. In women, after 12 months of androgen administration, hair diameters have not reached values of adult men.

Effects of Androgens and Antiandrogens on the Quantitative Immunohistochemistry of Gonadotrope Cells in Prepubertal Male Rats

In the male rat, androgens are involved in the feedback regulation of gonadotropin synthesis and secretion. Specific androgen-receptor blockade by the nonsteroidal antiandrogens, flutamide and Casodex, has proven to be a valid tool for studying androgen effects in vivo. The aim of the present study was to investigate the effect of antiandrogen administration at the pituitary level by evaluating the changes in gonadotropes through quantitative immunohistochemistry, and by comparing these alterations with the effect of androgen deprivation by castration either with or without subsequent androgen replacement. Male Sprague-Dawley rats (23 days old) were randomly divided into 5 groups for the following treatments: (a) controls; (b) flutamide-injected (10 mg/rat/day in a gelatin vehicle); (c) Casodex-injected (10 mg/rat/day in an oil vehicle); (d) castrated, and (e) castrated and dihydrotestosterone propionate-replaced (40 µg/rat/day in an oil vehicle). Groups were then sacrificed after 10 days of maintenance under each condition. Pituitaries were fixed in Bouin’s fluid and embedded in paraffin. Serial sections (4 µm) were obtained at different levels and immunostained by means of the primary murine monoclonal antibodies anti-FSH and anti-LH and a peroxidase-mediated EnVision System (Dako). Measurements of volume density (VD) and individual mean cell area were made by means of an image-analysis system (Imaging Technology, Optimas). Serum FSH and LH levels were determined by radioimmunoassay (RIA). Serum gonadotropin levels, VD, and mean cell area increased significantly in the flutamide-treated, Casodex-treated, and castrated groups (p < 0.05). Androgen replacement in the castrated rats, however, reduced VD, mean cell area, and serum gonadotropins to levels comparable to those of controls. We conclude that either androgen blockade by antiandrogens or castration produce an enhancement in the gonadotrope cell population in prepubertal rats, as shown by an increase in both VD and mean cell area, as well as an elevation in FSH- and LH-immunoreactive cells. These observations correlate well with the changes found in the levels of circulating gonadotropins as measured by RIA.

Androgen Regulation of Immunological and Biological Activities of Pituitary Follicle-Stimulating Hormone Isoforms inMale Rats

Follicle-stimulating hormone (FSH) is involved in the regulation and maintenance of gametogenesis. It exists in multiple molecular forms with different oligosaccharide structures which in turn are influenced by the hormonal milieu. Previous studies from our laboratory demonstrated that antiandrogen administration to immature male rats altered the biological activity and the distribution profile of pituitary FSH isoforms. The aim of this study was to examine possible modifications in pituitary FSH polymorphism throughout sexual development (10-, 32- and 75-day-old rats). In addition, the effect of androgen deprivation by castration (32-day-old rats) and its replacement with a nonaromatizable androgen – dihydrotestosterone – on pituitary FSH polymorphism was determined. Concanavalin A affinity chromatography was used to isolate groups of FSH isoforms according to their carbohydrate inner structure. Radioimmunoassay and Sertoli cell bioassay were used to evaluate FSH immuno- and bioactivities. Androgen rise in serum was accompanied by a marked increase in pituitary bio- and immuno-FSH content in 32- and 75-day-old rats. However, FSH pituitary content did not vary despite the significant increment observed in serum FSH levels after castration and decrease to control levels after androgen replacement. The distribution profile of immuno- and bioactive FSH changed throughout sexual maturation. The proportion of pituitary FSH isoforms bearing complex oligosaccharide structures (triantennary, bisecting, complete and truncated biantennary) increased with age, with a concomitant decrease in the proportion of isoforms bearing incomplete carbohydrate chains. The distribution profile observed in castrated 32-day-old rats was similar to that determined in 10-day-old animals. Androgen replacement restored the distribution profile to normal. These results suggest that androgens regulate the incorporation of sugar residues to the carbohydrate chains of pituitary FSH favoring the biosynthesis of complex-type oligosaccharide structures.

Androgens and masculinization of genitalia in the spotted hyaena (Crocuta crocuta). 3. Effects of juvenile gonadectomy.

Studies involving the administration of anti-androgens to spotted hyaenas during fetal development have raised questions concerning the precise contributions of steroids to phallic growth in these animals. If gonadal androgens promote postnatal penile growth in males, the following would be expected: (a) a period of accelerated growth accompanying achievement of puberty, and (b) a marked reduction in adult penile size and density of penile spines after gonadectomy. If a similar androgenic pubertal process stimulates clitoral growth in these highly 'masculinized' hyaenas, parallel observations in females would be expected; however, the role of oestrogens in accounting for female-typical clitoral development would also have to be considered. The results of the present study suggest a limited role, if any for androgenic stimulation of phallic growth. That is, penile growth was greater during the 10 month period preceding puberty, than during an 18-month period that included the traditional increase in pubertal androgens. In addition, pre-pubertal castration had minimal effects on penile length, diameter, or the presence of penile spines. In females, most clitoral growth also occurred before puberty, although pre-pubertal ovariectomy produced significant reductions in clitoral diameter and the elasticity of the urogenital meatus. These feminine characteristics which normally distinguish the female from the male phallus in this species, were partially restored by a brief period of oestrogen administration. Both sexes displayed erections many years after pre-pubertal castration. The results of the present study suggest that postnatal phallic growth is largely independent of gonadal steroids, with oestrogenic facilitation of female-typical clitoral characteristics in spotted hyaenas.

Endocrine and adrenergic pharmacological intervention in diseases of the prostate.

The physiology of the male urogenital apparatus and reproductive function is critically dependent on a healthy prostate. Since growth and function of the prostate are governed by androgens, endocrine interventions with the synthesis, uptake, or metabolism of these hormones are major pharmacological/therapeutic strategies in prostate diseases, e.g. cancer of the prostate (CaP) and benign prostatic hyperplasia (BPH). Pharmacological interference with androgen metabolism is associated with inevitable adverse effects. Therefore, it is important that such treatment be exercised with caution and weighed against its potential effects on the symptoms and outcome of the disease. α-Adrenergic blockade is an alternative treatment in BPH since α1-adrenoceptors are localized in the prostate stromal structures and considered to mediate an increased infravesical obstruction. Cancer of the prostate (CaP) is the most common cancer in the western male population with the highest incidence in Nordic countries (115/100 000) and in the USA, particularly in black Americans [1]. The incidence increases with age. About 30 to 35% of Swedish men at the age of 50 years have microscopic adenocarcinoma whereas the corresponding figure is more than 50% at the age of 80 years [2]. It has been estimated that about 7% of Swedish men will develop clinical CaP before the age of 75 years [2]. The other major disease of the prostate is BPH which is a histopathological diagnosis leading to benign prostatic enlargement and finally to bladder outlet obstruction. For the sake of simplicity, the clinical syndrome will be referred to as BPH in the following review. BPH is symptomatic in more than 40% of the ageing male population [3]. Shown in Table 1 are some prevalence numbers for CaP and BPH. Table 1 Prevalence of diseases of the prostate in relation to age. Given this situation, it is not surprising that diseases of the prostate have attracted considerable interest from the scientific community and the public. Compared with men from western societies, oriental men like the Japanese have a low incidence of CaP [4]. The higher incidence in oriental men living in the US compared with men in their native countries indicates that environmental as well as genetic factors influence the prevalence of this disease in the population. For BPH, development of effective pharmacological intervention therapies as well as new physical treatment modalities have challenged the classical surgical approaches to cure the disease. Even though the efficacy of drugs may be limited compared to surgical and physical means of treatment, they are often preferred because of the much lower complication risks [5]. A comparison of pharmacological and non-pharmacological treatments in terms of efficacy and complication risks is depicted in Figure 1. Figure 1 Efficacy of treatment methods for BPH in relation to risk of complications. Arbitrary dimensions on Y- and X-axes. TUMT=transurethral microwave treatment; TUNA=transurethral needle ablation; TUIP=transurethral incision of the prostate; TURP=transurethral ... The scope of this article is to describe the current possibilities and ideas for pharmacological intervention strategies, and to discuss their limitations and basis for further development of more advanced treatment programs.

Endocrine and adrenergic pharmacological intervention in diseasesof the prostate

Endocrine and adrenergic pharmacological intervention in diseasesof the prostate

Effects of sex steroids on plasma total homocysteine levels: a study in transsexual males and females.

Plasma total homocysteine (tHcy) levels are higher in men vs. premenopausal women, but it is not known whether this difference is related to sex steroids. The effects of cross-sex hormone administration on plasma tHcy levels were therefore investigated. Plasma tHcy levels were measured at baseline and after 4 months of treatment in 17 male-to-female (M-->F) transsexuals treated with ethinyl estradiol (100 micrograms/day), in combination with the antiandrogen, cyproterone acetate (100 mg/day), and in 17 female-to-male (F-->M) transsexuals treated with testosterone esters (250 mg/2 weeks, im). In M-->F transsexuals, the plasma tHcy level decreased from geometric mean 8.2 mumol/L to 5.7 mumol/L (P < 0.001); and in F-->M transsexuals, it increased from 7.7 mumol/L to 9.0 mumol/L (P = 0.005). In M-->F transsexuals, changes in serum sex hormone-binding globulin levels correlated negatively, and changes in plasma creatinine and albumin levels correlated positively, with changes in plasma tHcy levels. In F-->M transsexuals, changes in serum 17 beta-estradiol levels correlated negatively, and changes in plasma creatinine levels correlated positively, with changes in plasma tHcy levels. We conclude that tHcy levels decrease after estrogen + antiandrogen administration to male (transsexual) subjects, and levels increase after androgen administration to female (transsexual) subjects. These changes may be both primary and secondary to the anabolic/catabolic effects, as reflected by changes of creatinine and albumin levels after cross-sex hormone administration.

Expression and degradation of rat androgen receptor following castration, testosterone replacement and antiandrogens administration: analysis by Western blot and immunohistochemistry.

To elucidate the autoregulation of androgen receptor (AR) by androgen and antiandrogen, Western blot analysis and immunohistochemical study were performed. Castration reduced the immunodetected AR content, and nuclear staining was lost without cytoplasmic staining. Testosterone (T) supplement restored AR content. Quick response of AR content restoring following single administration of T was observed 48 hours after castration. The recovery of AR content detected by Western blot under each condition was accompanied by recovery of the reduced unclear staining intensities in the epithelia. Neither steroidal nor non-steroidal antiandrogens, chlormadinone acetate and flutamide, altered the AR content in normal rat ventral prostate 5, 12, 24 or 48 hours after single administration. Furthermore, neither of the drugs at various doses altered AR levels 12 hours after single administration. In summary, the rat AR is upregulated by androgen. Single administration of antiandrogens have no effect on immunodetected AR content.

Ornithine decarboxylase activity and polyamine levels in the epididymis of prepubertal rat after antiandrogen administration.

The antiandrogens flutamide and casodex have been administered subcutaneously (vehicle, 1, 5 or 10 mg per day) to prepubertal male rats for 10 days. A significant change of epididymal weight has been observed after both treatments, from the lowest dose used. Epididymal dihydrotestosterone concentrations were significantly increased in flutamide- or casodex-treated rats, while epididymal 3 alpha-androstanediol concentrations were affected only after flutamide administration, suggesting a differential effect on androgen metabolism between both antiandrogens. Ornithine decarboxylase (ODC) activity was significantly decreased by flutamide, and to a lesser extent by casodex. Antiandrogen administration resulted in a significant decrease in epididymal content of the polyamines putrescine, spermidine, and spermine. A slight but significant decrease in putrescine and spermidine concentrations, but not in spermine, was observed after flutamide treatment. However, casodex had no effects on polyamines levels. A decrease in putrescine concentration was detected only when ODC activity fell to rather low levels. Interference of the antiandrogens with the biological action of androgens on ODC activity was clearly seen in immature male rats. Therefore, both epididymal growth and differentiation, in correlation to ODC activity, would be severely affected at an early period of sexual development, such as prepuberty.

Pulmonary metastases, an occult prostatic adenocarcinoma and delayed administration of antiandrogens

The presentation of prostatic carcinoma with pulmonary metastases is unusual. The patient reported here presented with nodular lung metastases from an unknown primary site and 3.5 years later became symptomatic with a prostatic carcinoma. Subsequent hormonal therapy led to radiological regression of the pulmonary metastases. This case report demonstrates the progression of asymptomatic prostatic lung metastases with time and their response to delayed hormonal therapy, which is discussed.

Androgenic and antiandrogenic control on epidermal growth factor, epidermal growth factor receptor, and androgen receptor expression in human prostate cancer cell line LNCaP

Both androgen and antiandrogen treatments enhance the proliferation rate of the hormone-dependent prostate cancer cell line LNCaP, expressing a mutated androgen receptor (AR). We studied the modification of the expression of epidermal growth factor (EGF), of its receptor (EGF-R), and of androgen receptor (AR) in the LNCaP cell line, under basal conditions and during androgen (R1881) and antiandrogen hydroxy-flutamide (OH-FLU) treatment. After prolonged R1881 administration, a marked increase of EGF release was observed, completely blocked by the addition of OH-FLU. The Scatchard plot analysis of EGF-R binding revealed two classes of binding sites with high and low affinity. The administration of OH-FLU alone or combined with R1881 did not modify the affinity constants, while the low-affinity component disappeared after androgen administration. Both androgen and antiandrogen administration led to a significant increase of the EGF-R high-affinity component. AR mRNA and protein levels were downregulated by R1881 treatment. Following OH-FLU administration, AR mRNA was slightly downregulated, and there was not a strict parallelism between AR mRNA levels and AR binding capacity. When combined with R1881, OH-FLU partially counteracted the androgen-induced AR downregulation. Our data show that EGF-R binding capacity is the only parameter constantly raised in cell proliferation with respect to quiescent cells, and highlights the nonunivocal action of OH-FLU on androgen-induced effects.

Differential responses of biologically active luteinizing hormone secretion in older versus young men to interruption of androgen negative feedback.

To investigate the responsiveness of the healthy aging male hypothalamo-pituitary-gonadal axis to short term interruption of androgen negative feedback, we administered a selective nonsteroidal competitive antagonist of the androgen receptor, flutamide hydrochloride (250 mg, orally, three times daily for 3.5 days), to five older (aged 63-72 yr) and eight young (aged 21-30 yr) men. Pulsatile bioactive LH release was assessed by the rat interstitial cell testosterone bioassay in plasma sampled at 10-min intervals for 8 h overnight at baseline and after flutamide administration. Pituitary responsiveness was evaluated after two successive i.v. injections of 10 micrograms GnRH. Deconvolution analysis was used to estimate the number, amplitude, duration, and mass of bioactive LH secretory bursts and the half-life of biologically active hormone. At baseline, older men exhibited a significantly lower spontaneous bioactive LH secretory burst frequency than young men, with a median of 5 events/8 h (older) vs. 7.5 bursts/8 h (younger, P < 0.05). In older men, mean 8-h plasma bioactive LH concentrations increased significantly in response to flutamide (P = 0.006), and the 8-h calculated secretion rate of bioactive LH rose concomitantly. These increases were similar to responses in young men. However, during antiandrogen administration, the frequency of bioactive LH secretory bursts failed to rise in older men to the baseline value seen in young men. Moreover, older (but not young) men showed a significant prolongation of the LH secretory burst duration in response to flutamide treatment. On the other hand, the estimated half-life of endogenous bioactive LH increased significantly after flutamide ingestion in young compared to older individuals. After GnRH injections, older and young men secreted similar amounts of LH before flutamide administration, but during flutamide treatment, older men released more biologically active LH after the first GnRH stimulus [older men, 104 +/- 11 IU/L (median, 110); younger men, 44 +/- 8.4 IU/L (median, 40); P < 0.05]. Serum free testosterone concentrations rose significantly during flutamide exposure in both young and older men, but estradiol concentrations increased significantly only in young men. In summary, healthy older men exhibit a reduced (overnight) spontaneous bioactive LH secretory burst frequency. Pharmacological attenuation of androgen-mediated negative feedback increases mean serum free testosterone concentrations and plasma bioactive LH concentrations to a similar degree in older and young individuals, but different mechanisms operate in the two age groups. In older men, flutamide treatment amplifies the mass of bioactive LH secreted per burst by prolonging the LH secretory burst duration, whereas in young men, flutamide administration increases the apparent half-life of biologically active LHG significantly relative to values in older men. We conclude that competitive nonsteroidal blockade of the androgen receptor unmasks qualitatively altered mechanisms of increased bioactive LH release in healthy older men.

Clinical and economic considerations in the treatment of prostate cancer.

Prostate cancer is a growing health problem with considerable economic consequences. Despite progress in the management of this disease, few areas in medicine generate greater disagreement. The larger part of healthcare resources are allocated to 'halfway technologies' aimed at palliative intervention to prolong life, while a relatively small part goes to measures aimed at preventing or curing the disease. The aetiology of this cancer is multifactorial and no practical measures for primary prevention are known. The number of patients diagnosed with prostate cancer is increasing steadily. The age-adjusted mortality, however, has increased only slightly. In its early stages, prostate cancer is often asymptomatic and is usually not diagnosed until it has advanced. Programmes for the early detection of prostate cancer (screening) claimed to reduce morbidity and mortality are a matter of controversy. Furthermore, there has been much debate regarding optimal treatment in the early stages of the disease. Economic considerations have not as yet been integrated into studies concerning localised prostate cancer. The routine first-line treatment of advanced prostate cancer usually involves some type of endocrine treatment. The most straightforward technique is surgical castration. Oral estrogens are as effective as castration, but have significant cardiovascular adverse effects. These may possibly be prevented if estrogens are given parenterally. A third principal endocrine treatment is the administration of antiandrogens. Medical castration can be attained by the administration of recently developed synthetic peptides, gonadotrophin-releasing hormone {luteinising hormone-releasing hormone (LHRH)} (GnRH) analogue agonists which are given parenterally. The advantage of this type of medical castration is that the trauma of surgical castration and the adverse effects of oral estrogens are avoided. In an attempt to improve the results obtained with endocrine treatment, the concept of combining surgical or medical castration with antiandrogens was introduced. This combination could offer improved response rates and survival in a significant number of patients. However, this advantage must be weighed against the tolerability profiles and the high costs of antiandrogens and GnRH analogues. When using expensive drugs, the duration of treatment is a crucial factor in the total cost. As the length of treatment varies greatly between patients it is difficult to decide the most cost-effective alternative for a single individual. The patient's preference is an important factor when selecting treatment. When there is little or no difference in the effect of different regimens the total lifetime cost is important.(ABSTRACT TRUNCATED AT 400 WORDS)