Circulating unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol in elderly men and patients with prostatic tumours.

Circulating levels of 5 alpha-androstane-3 alpha,17 beta-diol (diol) were measured in 24 elderly men (50-80 years) without prostatic tumours and compared with 32 patients (54-84 years) with benign prostatic hypertrophy (BPH) and 32 patients (51-85 years) with carcinoma of the prostate (Ca). The mean +/- s.e.m. for serum concentrations of diol in patients with BPH, Ca and normals were 813 +/- 43, 524 +/- 35 and 635 +/- 28 pmol/l, respectively. There were significant differences between the mean values of these groups. The increased level of diol in BPH patients, when compared to the normals, corresponds to our previous report of elevated levels of its precursor, namely 5 alpha-dihydrotestosterone (DHT), in these patients. Although the mean values for diol were significantly different between the BPH and Ca patients, the scattered values within each group could not be utilized as an index to differentiate the two groups of patients.

Androgen metabolism by human prostatic tumours in organ culture.

Metabolism of testosterone and 5 alpha-dihydrotestosterone were investigated in benign and malignant human prostatic tumours maintained for 48 hr in organ culture. When tritiated testosterone was used as substrate there were significant differences between the metabolic pathways of the two types of tumour. Whilst the benign tumour had a predominantly reductive pathway leading to the formation of 5 alpha-reduced metabolites of testosterone, an oxidative pathway producing androstenedione was found to be the major pathway operative in the intermediate and poorly differentiated malignant specimens studied. In contrast to these differences observed in the metabolic pathway of testosterone when tritiated 5 alpha-dihydrotestosterone was used as substrate, no significant differences in the pattern of radiometabolites were observed.

Characterization and measurement of cytoplasmic and nuclear oestradiol-17 beta-receptor proteins in benign hypertrophied human prostate.

The demonstration and partial characterization of a high-affinity saturable binding component for oestradiol-17 beta in the cytosol and nuclear extract of the benign hypertrophied human prostate is reported. This binding component was found to precipitate with protamine sulphate and to exhibit marked specificity for oestradiol and diethylstilboestrol (DES) but not dihydrotestosterone (DHT) or progesterone. Analysis of oestradiol-labelled cytosol on low ionic strength glycerol gradients revealed a binding component with a sedimentation coefficient of 4S which was inhibited with DES but not DHT and destroyed either by preheating labelled cytosol at 45 degrees C for 30 min or by treatment with the sulphydryl blocking agent, parachloromercureobenzoate. The oestradiol-binding complex precipitated by ammonium sulphate was found to have an isoelectric point (pI) of 6.3 as analysed on polyacrylamide-gel plates. The oestradiol-binding component in the nuclear extract also exhibited similar steroid specificity and sedimented with a coefficient of 2.8S on high ionic strength glycerol gradients. Isoelectric focusing of the heparin-extracted nuclear oestradiol-binding complex revealed a pI of 6.0. The dissociation constants (Kd) and the concentrations of the cytoplasmic and nuclear oestradiol-binding sites in 19 samples of benign hypertrophied prostates were estimated by Scatchard plot analyses. The mean Kd and concentration of binding sites in the cytosol were 2.9 +/- 2.6 (S.D.) nmol/l and 11.7 +/- 8.4 fmol/mg protein respectively. The corresponding values for nuclear extract were 4.1 +/- 7.5 nmol/l and 347.1 +/- 415.5 fmol/mg DNA respectively. There was no significant difference between the mean concentration of oestradiol-binding sites in the two cellular fractions.

Steroid receptors in kidney tumours.

The presence of androgen and oestrogen receptors in normal and malignant human kidneys is reported. Characterization of these receptors was performed by glycerol gradient centrifugation and isoelectric focusing. Androgen receptors were detected in 40% of the tissues and its concentration was higher in the malignant kidneys. Oestrogen receptors were demonstrable in 8 out of 9 tumours, but only one out of 7 normal kidneys. The level of this receptor was extremely low.

Urinary unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol in patients with prostatic tumours.

A sensitive and reliable radioimmunoassay (RIA) for urinary unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol is described. The mean overall recovery of unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol was found to be 57.4%. The sensitivity of the assay was 79 fmol per assay tube and the intra and inter-assay variations ranged between 7.2% and 11.4%. The mean +/- SEM for the concentration of this androgen in the urine of normal men was 339.6 +/- 66.8 nmol/24 h. The corresponding values for patients with benign prostatic hypertrophy (BPH) and carcinoma of the prostate (Ca) were 297.8 +/- 44.7 and 1592.1 +/- 622.7 respectively. The mean value for Ca patients was significantly higher than either BPH (p less than 0.05) or normal subject (p less than 0.02), suggesting a differential urinary excretion pattern for unconjugated 5 alpha-androstane-3 alpha, 17 beta-diol between BPH and Ca patients. It is concluded that the combined measurement of this androgen in the plasma and urine provides a more accurate assessment of the profile of this hormone than a single plasma estimation.

Suppressive effects of surgical stress on circulating androgens during and after prostatectomy.

Changes in circulating testosterone (T) and dihydrotestosterone (DHT) levels were investigated 2 days before and 2, 7, 30 and 60 days after retropubic prostatectomy in 28 patients with benign prostatic hypertrophy. Following operation the concentrations of both steroids declined and reached minimal levels 2 days after surgery. One month post-operatively testosterone had recovered to its pre-operative value, whilst the recovery of dihydrotestosterone to its pre-operative level required a minimum period of 2 months. These data indicate the need for careful interpretation of any androgen measurement following surgery.

Relationships between oestradiol-17 beta, testosterone, dihydrotestosterone and 5 alpha-androstane-3 alpha, 27 beta-diol in human benign hypertrophy and carcinoma of the prostate.

The relationship between the concentrations of oestradiol, testosterone, dihydrotestosterone (DHT) and 5 alpha-androstane-3 alpha, 17 beta-diol in circulating blood and prostatic tissues was studied in patients with benign prostatic hypertrophy (BPH) and carcinoma of the prostate. All steroids were measured by radioimmunoassay. In patients with BPH the tissue concentrations of oestradiol, testosterone, DHT and 5 alpha-androstane-3 alpha, 17 beta-diol expressed per kg wet weight were 228.6 +/- 7.4 (S.E.M.) pmol, 1.29 +/- 0.06 nmol, 25.61 +/- 1.15 nmol and 1.43 +/- 0.10 nmol respectively. The corresponding values for carcinomatous tissues were 380.1 +/- 19.4 pmol, 7.20 +/- 1.10 nmol, 12.32 +/- 1.56 nmol and 1.99 +/- 0.32 nmol. Significant differences (t-test) were found between the mean concentrations of oestradiol (P less than 0.001), testosterone (P less than 0.001), DHT (P less than 0.001) and 5 alpha androstane-3 alpha, 17 beta-diol (P less than 0.05) in prostatic tissues of these two groups of patients. Significant negative correlations were observed between the tissue concentrations of oestradiol and DHT (r = -0.49, P less than 0.05) and between oestradiol and 5 alpha-androstane-3 alpha,17 beta-diol (r = -0.44, P less than 0.05) in BPH but not in malignant tissues. The plasma concentrations of oestradiol, testosterone, DHT and 5 alpha-androstane-3 alpha, 17 beta-diol in patients with BPH were 147.4 +/- 6.9 pmol/l, 18.4 +/- 1.2 nmol/l, 2.6 +/- 0.2 nmol/l and 0.84 +/- 0.04 nmol/ respectively. The corresponding values for patients with carcinoma of the prostate were 145.5 +/- 17.0 pmol/l, 17.3 +/- 2.4 nmol/l, 2.0 +/- 0.3 nmol/l and 0.56 +/- 0.06 nmol/l respectively. The mean plasma 5 alpha-androstane-3 alpha, 17 beta-diol was found to be significantly higher in patients with BPH (P less than 0.01) than with carcinoma. No significant correlations were found between the tissue concentrations of these steroids and the corresponding plasma values, which suggested that their metabolism and accumulation in prostatic tumours are independent of their plasma concentrations.

Relationship between prostatic cytoplasmic and nuclear androgen receptors in patients with carcinoma of the prostate.

Cytoplasmic and nuclear androgen receptors were measured in benign prostatic hypertrophy, untreated malignant prostates and diethylstilboestrol-treated malignant prostates. The levels of total androgen receptors in benign prostatic hypertrophy were not statistically different from those in the untreated or treated malignant prostates. Free cytoplasmic androgen receptors constituted only a small proportion of the total receptor concentration. A significantly higher level of free cytoplasmic receptors were present in the treated malignant prostates in comparison to the untreated ones. A significant positive correlation was observed between the total cytoplasmic and nuclear androgen receptors in both treated and untreated patients. A significant correlation was also observed between free cytoplasmic and total nuclear androgen receptors in untreated patients.

Androgen metabolism within the lobes of rhesus monkey prostate.

Testosterone metabolism was investigated in the caudal and cranial lobe of the rhesus monkey prostate. Analysis of the radiometabolites revealed that dihydrotestosterone and androstanediols are the main metabolites in the two lobes of the monkey prostate, suggesting that in this gland the main metabolic pathway is via the 5 alpha-reductive route. In contrast, the metabolic pathway for liver was found to be an oxidative one. The major metabolite in liver being androstenedione. There were no significant differences between the recovered radiometabolites in the two lobes of the prostate. The significance of the metabolic studies together with the differential uptake and receptor content of the two lobes of the monkey prostate have been discussed in relation to the zonal anatomy of the human prostate.

Age-related changes of serum 5alpha-androstane-3alpha, 17beta-diol in normal men.

Serum 5alpha-androstane-3alpha, 17beta-diol was measured in 60 normal men aged 23-80 years using sensitive and reliable radioimmunoassay techniques developed in our laboratory. When these normal men were classified into three age groups of 20-40, 40-60 and 60-80 years the values (mean +/- SEM) for serum 5alpha-androstane-3alpha, 17beta-diol were 857.3 +/- 36.3, 878.1 +/- 33.8 and 645.6 +/- 26.6 pmol/l, respectively. There were significant differences between the level of this steroid in the age group 60-80 when compared to either the 20-40 group (p less than 0.001) or the 40-60 group (p less than 0.001). No significance difference was found between the values for the two younger groups. The decline of this steroid with age corresponds with the diminishing level of testosterone and dihydrotestosterone previously reported from this laboratory.

Altered androgen metabolism in carcinoma of the prostate.

Testosterone metabolism was investigated in benign hypertrophied and malignant prostates using a tissue culture technique. The results demonstrated a distinct difference between the two types of tumour. The benign tissue was found to metabolize testosterone via a reductive pathway. The main radiometabolites were found to be dihydrotestosterone and androstanediols. On the other hand, the malignant tumours showed less ability to metabolize testosterone and the metabolism by these tumours was found to be an oxidative one, with the main metabolite being androstenedione.

Serum testosterone and dihydrotestosterone in carcinoma of the prostate.

Serum testosterone (T) and dihydrotestosterone (DHT) were measured by a sensitive and reliable radioimmunoassay in 42 normal subjects and 33 age-matched patients with carcinoma of the prostate. The mean +/- s.e. for serum testosterone in normal subjects was 16.74 +/- 0.76nM and the corresponding value for patients with carcinoma was 20.94 +/- 1.48nM. Statistical analysis of the results showed a significant increase in T level in patients with carcinoma of the prostate (P less than 0.01). In contrast, there was no difference in DHT concentration between the two groups, values being 2.43 +/- 0.09 and 2.06 +/- 0.09nM for normal subjects and patients respectively. The means +/- s.e. for T/DHT ratio in controls and patients were 6.8 +/- 0.2 and 12.8 +/- 1.3 respectively. The difference was highly significant (P less than 0.001). The wide range of variation for T in patients with carcinoma would suggest that although mean T is higher in these patients, this measurement alone is of little practical value, whereas T/DHT ratio is a more reliable parameter in evaluating the androgen changes in these patients. The significance of these findings in relation to the aetiology of the disease is discussed.

Receptor proteins for androgens in prostatic disease.

The suitability of an exchange assay with methyltrienolone (R1881) for the measurement of androgen receptors in human prostatic tumours has been investigated. Having established the specificity of this compound for androgen receptor assay, a pilot study was carried out to measure dihydrotestosterone (DHT) receptor in 27 cases of benign hypertrophy and 18 cases of malignant tumour of the prostate.

Receptor protein for dihydrotestosterone in nuclei of the female prostate of Praomys (Mastomys) natalensis.

An investigation was carried out to identify and characterize the binding of androgens within the nuclei of the prostate from female Praomys (Mastomys) natalensis. After in vivo and in vitro labeling with tritiated androgens, the tissue was subjected to cell fractionation and the nuclear fraction was purified. Gel exclusion chromatography and sucrose density gradient centrifugation of the nuclear extract showed the presence of a steroid receptor complex having a sedimentation coefficient of 3 S. Subsequent analysis of the bound radioactivity revealed that more than 90 per cent of the recovered tritiated steroid was dihydrotestosterone. This binding was found to be temperature dependent and could not be shown in liver tissue. The behavior of this nuclear steroid receptor complex is compared with that of the male Mastomys and the rat. It is suggested that the female Mastomys could be used as an experimental model for studying hormone effects on the prostate.

The ultrastructure of the male and female prostate of Praomys (Mastomys) natalensis. I. Normal, castrated and ovariectomised animals.

Male ventral and female prostates of Praomys (Mastomys) natalensis were examined with the electron microscope. The findings support and add to information obtained with the light microscope on tissues from normal, castrated and ovariectomised animals. Our results indicate that although the female prostate may be considered a homologue of the male ventral ventral prostate anatomically and histologically, there are differences in sub-cellular morphology and hormone dependence. Cells of the intact ventral prostate of the male are characterised by prominent dilated Golgi vesicles and electron-dense "mature secretory granules" seen in the apical region of the cell. In the cells of the female prostate these features are absent. These morphological differences reflect the influence of hormones upon the cells, as shown by the reduction of the dilated Golgi vesicles in the castrated male and conversely, their occasional presence in the cells of the oestrous female. Comparison of castrated and ovariectomised animals shows that the male ventral prostate is much more dependent on androgens than the female is on ovarian hormones. There are several modes of secretion in the male ventral and the female prostate. These are by acellular and cellular blebbing, by a variety of secretory vesicles into the acinar lumina, and by a system of "double walled" vesicles not previously described.