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Search for other papers by C. B. DHABUWALA in
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Search for other papers by C. G. PIERREPOINT in
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The venous drainage of the canine prostate gland has been studied in nine dogs after post-mortem intravenous injection of a coloured suspension of latex. A submucosal cavernous plexus of the prostatic urethra continuous with that of the penis, and a previously unnamed vessel that drains this plexus into the prostatico-vesical vein are described. The eferential vein was found to open variably, but always into the prostatic venous system. The data support the concept that a very small retrograde blood flow would take androgenrich blood from the deferential vein into the prostate gland.
Search for other papers by C. R. EVANS in
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SUMMARY
Nuclei have been isolated from canine prostatic tissue previously incubated with tritiated testosterone or tritiated 5α-androstane-3α,17α-diol. The protein-bound radioactivity has, in both cases, been shown to be associated with 5α-androstane-3α,17α-diol. The formation and translocation of this steroid to the nucleus supports previous evidence that it has an active part to play in prostatic function in the dog. The formation from testosterone of another tritiated steroid, possibly 5α-dihydrotestosterone, was also demonstrated although this product did not enter the nucleus and was apparently bound to the nuclear membrane.
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SUMMARY
A specific receptor protein has been demonstrated for 5α-androstane-3α, 17α-diol in cytoplasmic extracts of normal and hyperplastic canine prostates. The receptor molecule, with a sedimentation coefficient of 4–5S, has been identified by the use of sucrose gradient centrifugation of tissue fractions which had been labelled in vitro with tritiated 5α-androstane-3α, 17α-diol. The receptor showed a relatively high affinity for this compound whereas binding could not be demonstrated with other labelled C19 steroids. In addition binding of tritiated 5α-androstane-3α, 17α-diol was not affected by the presence of 50-fold excesses of other C19 steroids.
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Search for other papers by C. G. PIERREPOINT in
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SUMMARY
Explants of canine prostate were cultured in a defined medium for periods of up to 5 days with and without added steroids. Testosterone and 5α-dihydrotestosterone failed to maintain their histological integrity and induced a greatly increased formation of stromal elements. Epitestosterone and 5α-dihydroepitestosterone were partially successful in maintaining epithelial height although secretory activity was not preserved. The only steroid that sustained epithelial height and secretory activity whilst keeping stromal growth at a minimum was 5α-androstane-3α, 17α-diol. The three other epimeric androstanediols were ineffective.
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Search for other papers by A. B. M. ANDERSON in
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Placental tissue was removed from a ewe at 127 days' gestation and, without separating foetal from maternal contributions, incubated as a mince (4 g) with equimolar amounts of [4-14C]androstenedione (2 μCi, 56 mCi/mmol) and [1,2-3H]epitestosterone (15 μCi, 420 mCi/mmol) at 39·5 °C. The reactions were stopped after 2 h by adding acetone and freezing. The non-radioactive carrier steroids, androstenedione, testosterone, epitestosterone, oestrone, oestradiol-17β, oestradiol-17α, testosterone sulphate and epitestosterone sulphate were added in 500 μg amounts.
After mixing, steroids and their conjugates were extracted from the incubation medium with 2 × 100 ml acetone followed by 2 × 100 ml ether: ethanol (3:1, v/v). Nonpolar lipid material was removed by partitioning the pooled, dried extract between 70% (v/v) aqueous methanol and light petroleum (b.p. 40–60 °C). The methanol was evaporated and unconjugated steroids extracted from the aqueous residue with 3 × 30 ml ether before saturating with ammonium
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Tenovus Institute for Cancer Research, Welsh National School of Medicine. The Heath, Cardiff, CF4 4XX and *41 Rodney Street, Liverpool, LI 9EN
(Received 1 July 1977)
Although our knowledge of spermatogenesis is good (see Steinberger & Steinberger, 1975), we have yet to appreciate fully the integrated hormonal requirements of this process (see Courot, 1976). Infertility in men has proved an obstinate condition to treat, although gonadotrophin and androgen therapy have achieved some success. Prolactin remains something of an enigma in men although there is now considerable evidence that it can have profound action both on the testis and on the accessory sex glands of experimental animals.
It was decided to measure routinely the concentrations of testosterone and prolactin in the plasma of men attending an infertility clinic, for comparison with fertile men requesting vasectomy. The 'infertile' men (sperm count range/ml excluding azoospermic men was 5 × 103−305 × 106; median
Search for other papers by ANNE B. M. ANDERSON in
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This paper reports the metabolism of labelled androstenedione and pregnenolone by the liver of foetal sheep. Isolation of reduction products was a major feature of this study.
The livers were removed from sheep foetuses at (a) 129 days', and (b) 143 days' gestation immediately after Caesarean section under spinal analgesia. The tissue was maintained at 0 °C until incubated 1 h later. Chopped tissue (2 g) was incubated in 24 ml Krebs—Ringer bicarbonate glucose solution at 39–5 °C in 95% O2:5% CO2 with the following: incubation (a), 57·4 nmol each of [4-14C]androstenedione (34·8 mCi/mmol) and [7α-3H]pregnenolone (14·7 Ci/mmol); incubation (b), 57·4 nmol of [4-14C]androstenedione (34·8 mCi/mmol). Reactions were stopped after 2 h with acetone containing 500 μg each of the listed carrier steroids (Table 1). The following were unobtainable as sulphates and were added as free steroids to the conjugate fraction before
Search for other papers by D. W. WILSON in
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Tenovus Institute for Cancer Research, Welsh National School of Medicine, Heath Park, Cardiff, CF4 4XX
(Received 24 March 1977)
A technique for the analysis and measurement of C19-steroids by high-resolution selected ion monitoring has been used in this laboratory to study the level of endogenous steroids in human prostatic tissue (Millington, 1975; Millington, Buoy, Brooks, Harper & Griffiths, 1975). A similar procedure has now been used as a reference method to determine the concentration of oestradiol-17β in plasma samples from a quality control scheme for the Supra-Regional Assay Service (SAS) in the United Kingdom. Results from this combined gas chromatographic-mass spectrometric (GC-MS) method were compared with those obtained from the assay of oestradiol-17β with the routine radioimmunoassay (RIA) procedure used in this laboratory (Golder, Phillips, Fahmy, Preece, Jones, Henk & Griffiths, 1976).
All gas Chromatographie column packings and the reagent bis-(N,O)trimethylsilyl acetamide were supplied by Jones Chromatography Limited, Llanbradach, Glamorgan.
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Search for other papers by C. G. PIERREPOINT in
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A receptor protein that selectively binds oestrogens has been demonstrated in the cytosol of the canine prostate gland. The steroid–receptor complex was found to have a sedimentation coefficient of 4–5 S with respect to bovine serum albumin after sucrose density-gradient centrifugation. The high affinity and low capacity of the protein for oestrogens was indicated by displacement studies, which gave a value of 3·8 ± 1·53 (s.d.) × 10−10 mol/l for the dissociation constant. A metastasizing prostatic tumour was also shown to possess this receptor, with binding properties similar to those exhibited by the receptor in normal prostatic cytosol. The implications of these findings are discussed with regard to normal prostatic function in the dog and the virtually inevitable advent of prostatic hyperplasia with age in this species.
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SUMMARY
A method is described for the resolution and individual quantitation of cortisol, cortisone, 11-deoxycortisol and corticosterone in foetal sheep plasma. The steroids were extracted by solvent partition and separated by LH-20 Sephadex column chromatography. Radioimmunoassay was used for the measurement of 11-deoxycortisol and cortisone and competitive protein-binding for corticosterone and cortisol.
The relative levels of these steroids in the plasma of chronically catheterized sheep foetuses from 12 days before birth to term and then in the newborn lamb until 2 days of age are recorded.
Cortisol gradually increased from a basal concentration of between 0·5 and 3·0 μg/100 ml plasma between days 12 and 5 pre partum, and then rose rapidly to 10 μg/100 ml plasma during the last 5 days of pregnancy to reach a maximum during or just after birth. Two days post partum the levels had fallen to approximately 3 μg/100 ml plasma.
The mean value for 11-deoxycortisol between days 8 and 3 pre partum was 0·4 μg/100 ml plasma and increased in the final days before delivery to 1·0 μg/100 ml. Corticosterone initially showed slightly higher levels (∼ 1·5 μg/100 ml) in the earlier period of investigation but then fell during the immediate pre-partum period to 0·8 μg/100 ml. Cortisone was not detected at any stage of the investigations.
The relationship between levels of cortisol and 11-deoxycortisol in foetal plasma and myometrial contractility is shown. An increase in uterine activity was seen to occur at the time that cortisol levels were at their maximum. The 11-deoxycortisol values throughout this particular study remained low.
The results are discussed in relation to recorded levels in the adult and to previous studies in vitro with regard to changing steroid biosynthetic enzyme activity.
