F. Sciarra

Evidence that Serenoa repens extract displays an antiestrogenic activity in prostatic tissue of benign prostatic hypertrophy patients

A double-blind placebo-controlled study was performed in 35 benign prostatic hypertrophy (BPH) patients never treated before. The patients were randomized into two groups, the 1st (18 cases) receiving Serenoa repens extract (160 mg t.d.) for 3 months up to the day before the operation of transvesical adenomectomy and the 2nd (17 cases) receiving placebo. Steroid receptors were evaluated in the nuclear (n) and cytosolic (c) fraction using the saturation analysis technique (Scatchard analysis or single saturating-dose assay) for androgen (AR) and estrogen (ER) receptors and the enzyme immunoassay (EIA) for ER and progesterone receptors (PgR). Scatchard analysis of ERc and ERn revealed the presence of two classes of binding sites, one with high-affinity low-capacity binding and the other with low-affinity high-capacity binding. In the untreated BPH group, ER were higher in the n than in the c fraction: ERn were positive in 14 cases and ERc in 12 of 17 cases. In the BPH group treated with S. repens extract on the contrary, ERn were negative for both binding classes in 17 cases and ERc in 6 of 18 cases. Using EIA, ERn and ERc were detected in all 15 samples examined, but in the treated group, ERn were significantly (p less than 0.01) lower than in the untreated group, whilst ERc remained almost unchanged. Similar results were obtained measuring PgR: the n fraction of the treated group prostatic samples was significantly (p less than 0.01) lower than that of the untreated group.(ABSTRACT TRUNCATED AT 250 WORDS)

Insulin-like growth factor-I and -II in human benign prostatic hyperplasia : Relationship with binding proteins 2 and 3 and androgens

In prostatic tissue, androgen action may be mediated by growth factors such as insulin-like growth factor-I (IGF-I) and II (IGF-II), which are mitogenic for prostatic cells and modulate the stroma-epithelium interaction. IGF-binding proteins (IGFBPs) have an autocrine and/or paracrine role in regulating the local actions of the IGFs. In this study, testosterone, dihydrotestosterone (DHT), 3 alpha androstanediol (3 alpha diol), IGF-I, IGF-II, IGFBP2, and IGFBP3 concentrations were evaluated in human benign prostatic hyperplasia (BPH) tissue. Samples of prostate tissue were removed by suprapubic prostatectomy from twelve BPH patients. Androgen tissue levels were determined by radioimmunoassay after purification on celite microcolumns. IGF-I, IGFBP2, and IGFBP3 were measured by radioimmunoassay, and IGF-II by immunoradio metric assay, after acidification and chromatography on Sep-pak C18 Cartridges for IGF-I and IGF-II. Androgen concentrations, expressed in ng/g tissue (mean +/- SE), were 0.51 +/- 0.05 for testosterone, 5.3 +/- 0.16 for DHT, and 1.1 +/- 0.07 for 3 alpha diol. IGF-I, IGF-II, IGFBP2, and IGFBP3 levels were 24 +/- 3.7, 121 +/- 14 ng/g tissue and 0.44 +/- 0.05 and 1.2 +/- 0.17 micrograms/g tissue, respectively. No correlation between IGF-I, androgens, and IGFBPs was found. IGF-II was positively correlated with DHT (r = 0.78; p = 0.003) and 3 alpha diol (r = 0.66; p = 0.021) but not with IGFBPs. These data suggest that in BPH, DHT modulates the IGF system by increasing IGF-II without modifying IGFBPs. Therefore, the stroma-epithelium interaction, which plays an important role in prostatic growth, may be regulated by DHT through IGF-II.

Two different pathogenetic mechanisms may play a role in acne and in hirsutism

OBJECTIVE Acne is one of the most common skin disorders. Androgens are known to play an important and possibly central role. Androgens secreted from ovaries and adrenal glands (androstenedione, dehydroepiandro‐sterone and its sulphate, testosterone) and target tissue‐produced androgens (testosterone and its 5α‐reduced metabolite, dihydrotestosterone) have been implicated. Although the sebaceous gland and the hair follicle form a single morphological entity, the pilosebaceous unit, acne and hirsutism do not always appear concomitantly, thus leading to the supposition that these two structures may have different degrees of sensitivity to similar androgenic stimulation.

Antiandrogens: clinical applications.

Antiandrogens, preventing androgen action at target tissue level, are used in the treatment of various androgen-dependent diseases. Pharmacologically these substances have either a steroidal structure, like cyproterone acetate (CPA) and spironolactone (SPL), or a non-steroidal structure, like flutamide (FLU). In women with hyperandrogenism (PCO syndrome, idiopathic hirsutism, acne), clinical benefit may be obtained with CPA, which also displays a progestational activity and an antigonadotropic effect. CPA (25-50 mg/day) is used in combination with ethinyl-estradiol (EE) (20-30 micrograms/day) in reversed sequential regimen. SPL, less effective than CPA may be employed in moderate hirsutism and acne at dosages of 100-200 mg/day. During SPL treatment menstrual irregularities are frequent: in this case an association with oral contraceptives is indicated. SPL + bromocriptine (2.5-5 mg/day) has been experienced with success in PCO syndrome. The pure antiandrogen FLU, inducing progressive increase in LH and testosterone secretion, may be used only in combination with oral contraceptives. In men antiandrogens have been tested in BPH and prostatic carcinoma. In BPH the decrease in nuclear receptors and DHT nuclear content during CPA or FLU may represent the rational base of the medical treatment. An improvement in urinary obstructive manifestation has been observed with CPA alone or associated with tamoxifen (100 mg + 100 mg day). In advanced prostatic carcinoma antiandrogens represent a good alternative to estrogen therapy with less side effects and in combination with surgical or medical castration (LH-RH analogues) achieve a complete androgen blockade. An increase in the percentage of remissions and survival has been reported.

INFLUENCE OF HYPERPROLACTINAEMIA DUE TO METOCLOPRAMIDE ON GONADAL FUNCTION IN MEN

Five clinically normal male volunteers were given metoclopramide, 10 mg t.d.s. for 6 weeks. During treatment prolactin concentrations were elevated (over 50 ng/ml) in all. LH, FSH, testosterone and cortisol concentrations were not altered. No change was observed in LH or FSH responses to LHRH testing 4 weeks after the beginning of therapy, compared with pre‐treatment values. A reduction in seminal volume and total sperm count were observed in each subject. Four noticed a decrease in libido and three lost spontaneous erections. While the metoclopramide‐induced hyperprolactinaemia could be the cause of the observed changes in semen and erectile activity, it is possible that this dopamine receptor blocking drug might directly affect central or peripheral mechanism of erection, the testes or accessory organs.

Simultaneous determination of 5α reduced metabolites of testosterone in human plasma

Abstract 17β-Hydroxy-4-androsten-3-one (testosterone), 17β-hydroxy-5α-androstan-3-one (dihydrotestosterone), 3α,17β-dihydroxy-5α-androstane (3αadiol) and 3β,17β-dihydroxy-5α-androstane (3βadiol) were measured simultaneously in the same sample of human peripheral plasma using celite microcolumn chromatography and two antisera (anti testosterone-6-carboxy-methyl-oxime BSA for testosterone and anti 5α-dihydrotestosterone-l-carboxy-ethyl-thioether BSA for dihydrotestosterone, Sαadiol and 3βadiol). The concentrations (ng/dl ± SD) of the four androgens in normal young males and in normal females are respectively: 610.33 ± 137.94 and 30.4 ± 9.1 for testosterone, 47.8 ± 9.4 and 16.8 ± 6.7 for dihydrotestosterone, 28.7 ± 8.6 and 10.8 ± 3.03 for 3αadiol and 54.9 ± 29 and 23.9 ± 6.6 for 3βadiol. These values decrease significantly in elderly males. Results obtained in orchiectomized patients and in hirsute women suggest that the determination of 5α reduced metabolites in peripheral plasma may be a useful clinical parameter for the evaluation of peripheral androgen metabolism.

Epidermal growth factor binding and steroid receptor content in human benign prostatic hyperplasia

The receptor for epidermal growth factor (EGF-R) was characterized on membrane fractions from human benign prostatic hyperplasia (BPH). Specific binding of [125I]EGF reached equilibrium after 40 min at 25 degrees C and was stable for up to 120 min. Saturation analysis of EGF-R, performed by incubating the membranes with 0.0156-15 nM [125I]EGF in the presence and in the absence of 100-fold excess of cold EGF for 60 min, revealed the presence of two classes of binding sites with high and low affinities (Kd = 0.35 +/- 0.23 and 9.60 +/- 2.87 nM respectively). Competition experiments revealed that FSH, insulin and calcitonin did not compete with [125I]EGF. The simultaneous determination of EGF-R and that of estradiol (ER), progesterone (PR) and androgen receptors (AR) was performed using the same buffer to homogenate the tissues and to obtain cellular membranes. The steroid receptors (SR) were determined by means of the dextran-coated charcoal method. There was a significant negative correlation between nuclear SR and binding capacity of EGF-R. The presence of specific and high affinity binding sites for EGF and the modulation of the level of these sites by steroid receptors suggest a possible role of EGF in prostatic hyperplasia.

FAMILIAL MALE PSEUDOHERMAPHRODITISM WITH GYNAECOMASTIA DUE TO 17β‐HYDROXYSTEROID DEHYDROGENASE DEFICIENCY. A REPORT OF 3 CASES

Three sisters with male pseudohermaphroditism due to 17β‐hydroxysteroid dehydrogenase deficiency are described. On the basis of a 46 XY karyotype and female phenotype all subjects were thought to have the testicular feminization syndrome. At puberty the two older patients developed signs of virilization and gynaecomastia. In these patients the plasma androstenedione level was 4‐5 times higher than normal, whilst the plasma testosterone level was low compared to the normal range and, under basal conditions, their plasma and rostenedione to testosterone ratio was 20–25 times higher than normal. Interestingly, in the third, prepubertal case, the basal androstenedione to testosterone ratio was normal but became six times higher than normal after hCG stimulation. These data support the diagnosis of male pseudohermaphroditism due to 17β‐hydroxysteroid dehydrogenase deficiency and underline the diagnostic value of the hCG stimulation test prepubertally.

Human kidney steroid receptors

Abstract Saturation analyses, binding kinetics and agar gel electrophoresis performed on normal human kidney tissue revealed the presence of a specific progesterone receptor in all the specimens studied and in one, a specific estradiol receptor was observed, Progesterone binding had a rapid association and a slow dissociation reaction. The binding capacity for estradiol and progesterone was not significantly different, whereas the binding affinity for progesterone was lower than that for estradiol. These results on progesterone receptors in the cytosol of normal human kidney tissue offer an interesting field of investigation considering the estrogen-induced renal adenocarcinoma in animals and the possibility of progestational therapy for tumour regression in humans.

A clinician looks at androgen resistance

Androgen resistance in genetic males occurs when gonadotropins and testosterone are normal, but the physiological androgen response in androgen target organs is absent or decreased. In androgen-dependent target tissues two main defects may be found: 1) defective testosterone metabolism (5 alpha-reductase type 2 deficiency) and 2) anomalies in androgen receptors (androgen insensitivity syndrome (AIS)). The clinical manifestations of these defects vary from subjects with female external genitalia to subjects with mild forms of impaired masculinization. In particular, in the complete form of AIS (CAIS) the phenotype is feminine, and in the partial form (PAIS) the external genitalia are ambiguous with an extremely variable phenotype. The diagnosis requires clinical, hormonal, genetic, and molecular investigation for appropriate gender assignation and treatment. In AIS, cloning of androgen receptor cDNA using the polymerase chain reaction, denaturing gradient gel electrophoresis, and nucleotide sequencing have enabled a variety of molecular defects in the androgen receptor to be identified. The complexity of phenotypic presentation of AIS probably reflects the heterogeneity of androgen receptor gene mutations, but to date a relationship between genotype/phenotype has been difficult to establish, with the same point mutation reported to be associated with different phenotypic expressions. Other factors must therefore also contribute to the clinical presentation of AIS, although none have yet been identified. Establishing the functional consequences of androgen receptor mutations in vitro systems and correlating them with clinical presentation may ultimately provide an explanation for the variable clinical presentation of AIS and perhaps enable prediction of the response to androgen therapy in infants with PAIS.