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The 17α and 17β epimers of androstenediol (3β,17α-(or 17β)-dihydroxyandrost-5-ene) are both present in umbilical cord plasma (average total concn 120 μg./100 ml.) and in the urine of infants and adults, but the ratio is approximately 9:1 in foetal blood and infants' urine, and 1:2 in adults' urine (Shackleton, Livingstone & Mitchell, 1968). The 17β-hydroxy epimer of androstenediol has been isolated from foetal tissue (although it was possibly not distinguished from the 17α epimer) after perfusion with DHA (3β-hydroxyandrost-5-en-17-one) and DHA sulphate (Bolté, Wiquist & Dicsfalusy, 1966). It has been suggested that in early life the ratio in favour of 17α-androstenediol is due partly to the preferential 16α-hydroxylation of the 17β epimer in foetal tissue together with its preferential aromatization in the placenta to form oestradiol (Shackleton et al. 1968). In support of this suggestion it has now been shown that there is a preferential 16α-hydroxylation of the 17 β epimer

SUMMARY

C₁₉-16-unsaturated steroids have been extracted from the urine and spermatic vein plasma of a mature boar and identified by thin-layer chromatography, gas—liquid chromatography and combined gas—liquid chromatography—mass spectrometry. 5α-Androst-16-en-3β-ol (approximately 250 μg./1.) was identified in the urinary glucuronide fraction. This compound and the 3α-epimer occurred in the spermatic vein plasma predominantly as sulphates but a small quantity of the 3α-isomer was extractable with ether prior to hydrolysis of steroid conjugates. Traces of 5,16-androstadien-3β-ol have been tentatively identified in the plasma sulphate fraction; 5α-androst-16-en-3-one occurred as free steroid. No 16-unsaturated steroids were found in the plasma glucuronide nor in urinary sulphate fractions. The latter contained an unidentified compound of similar polarity to the C₁₉-16-unsaturated steroids.

Neutral 17-oxosteroids were measured in extracts obtained from both the urine and spermatic vein plasma. Of the dehydroepiandrosterone (DHA) in the urine 60% occurred as sulphate and 40% as glucuronide with only traces as free steroid. Androsterone and aetiocholanolone occurred only as glucuronides. In the spermatic vein plasma, DHA occurred predominantly as sulphate with small amounts as glucuronide and free steroid.

It is now generally accepted that dehydroepiandrosterone (DHA) is one of the androgens secreted by the human adrenal gland and that it arises from the side-chain cleavage of 17α-hydroxypregnenolone (Soloman, Carter & Lieberman, 1960; Gaul, Lemus, Kline, Gut & Dorfman, 1962; Deshpande, Jensen, Carson, Bulbrook & Doouss, 1970; Jones, Groom & Griffiths, 1970). Although the biosynthetic pathways by which the hormone is synthesized have been established, the precise requirements for the side-chain cleavage of 17α-hydroxypregnenolone and the factors affecting the reaction are as yet unknown. For this reason examination of the kinetics of the enzyme involved in the side-chain cleavage of 17α-hydroxypregnenolone (17-desomolase) was undertaken.

Human adrenal glands, obtained at operation from patients with advanced breast cancer, were fractionated in a Beckman Ultra Centrifuge (Model L2–65B) according to the procedure of Allfrey, Littan & Mursky (1964). Tritiated 17α-hydroxypregnenolone (sp.act. 19·9 Ci/mm) used as substrate and [¹⁴C]DHA (sp.act. 57·1

* Service de Chirurgie and †Service de Médecine Interne et Laboratoire d'Investigation Clinique, Institut Jules Bordet, Centre des Tumeurs de l'Université Libre de Bruxelles, 1 rue Héger-Bordet, Brussels, Belgium and ‡Human Reproduction Research Unit, Department of Gynaecology and Obstetrics, Hôpital Saint-Pierre, Brussels, Belgium

(Received 14 November 1977)

The regulation of the production of steroid sex hormones in postmenopausal women is not well understood. Since the conversion of the adrenal steroids 4-androstene-3,17-dione and dehydroepiandrosterone (DHA) or its sulphate within the peripheral non-endocrine tissues is the most important source of steroid sex hormones in such women (Baird, Horton, Longcope & Tait, 1969; Grodin, Siiteri & McDonald, 1973), we have investigated the role of corticotrophin (ACTH) in this process.

Three women (64–78 years old, 14–28 years after the menopause) were given a constant infusion of synthetic β^1–24-ACTH (0·25 mg in 250 ml 5% glucose solution) for 2 h and blood was withdrawn at

University of Chicago, Pritzker School of Medicine, Chicago, Illinois 60637, U.S.A.

(Received 18 July 1975)

The biochemical basis of the genetically determined difference in sexual hair growth between oriental and caucasian men has not been established. Oriental men have plasma testosterone levels equal to those of Occidentals. However, the former group has low 17-oxosteroid excretion and beard growth can be induced by androgen, findings compatible with hypoandrogenism (Kobayashi, Lobotsky & Lloyd, 1966). Available data do not exclude differences in plasma testosterone binding or levels of other androgens. Therefore, the following studies were undertaken.

Six, 24 ± 0·81 (S.D.) -year-old normal graduate students of oriental descent (3 Chinese, 3 Japanese) who were unable to grow beard, moustache, or sideburns were compared with six, 24 ± 4·6-year-old, Caucasian graduate students who were fully virile. Hormone levels were measured in single, fasting, 08.00 h blood specimens.

Plasma testosterone, androstenedione, dihydrotestosterone, and dehydroepiandrosterone (DHA) were

SUMMARY

Injection of a 'rapid-acting' preparation of porcine adrenocorticotrophic hormone (ACTH) into three boars resulted in a rapid rise in plasma testosterone levels which accompanied the expected rise in plasma corticosteroids. Urinary dehydroepiandrosterone (DHA) levels were measured in one boar and were found to be raised also. The results suggest that the effect involved enhanced testicular steroid activity and was related to the dosage of ACTH employed. This action of ACTH is thought to be mediated through the adrenal cortex since injection of cortisol elicited a rise in testosterone similar to that observed after injection of ACTH. ACTH had no effect on testosterone levels in a castrated boar. When a 'longacting' preparation of ACTH was administered to two boars twice daily for 5 days, testosterone levels were depressed. It was concluded that ACTH may bring about an increase or a decrease in plasma testosterone levels in the boar depending upon the length of time increased levels of ACTH are present in the circulation.

Department of Clinical Endocrinology, Imperial Cancer Research Fund, Lincoln's Inn Fields, London, WC2A 3PX

(Received 2 August 1974)

Evidence has often been presented for the existence of multiple 3β-hydroxysteroid dehydrogenase/3-oxosteroid isomerase systems on the basis of preferential conversion of only one of the several possible substrates of these enzymes (Weliky & Engel, 1963; Neville, Webb & Symington, 1969). Three, or possibly four, substrate-specific isomerases have been demonstrated in mammalian adrenal glands (Alfsen, Baulieu & Claquin, 1965; also see Neville et al. 1969). More recently the 3β-hydroxysteroid dehydrogenase/isomerase system of sheep adrenal cortex microsomes has been isolated; purification of the enzymes by ion exchange chromatography revealed no separation of activities towards dehydroepiandrosterone (DHA) and pregnenolone (Ford & Engel, 1974). However, similar information on the human adrenal gland is lacking and since this enzyme system(s) might be important in the production of cortisol and androgens, an attempt has been made to investigate

A comparison has been made between the method of Thomas & Bulbrook (1964, 1966) for estimation of urinary 11-deoxy-17-oxosteroids and a modification of this procedure, utilizing isotopically labelled internal standards to assess accuracy.

To each urine sample was added 45·0 mμc each of [4-¹⁴C]dehydroepiandrosterone and [7α-³H]aetiocholanolone. Steroid conjugates were then extracted, hydrolysed and washed with sodium dithionate as described by Thomas & Bulbrook (1964). Separation of aetiocholanolone from dehydroepiandrosterone (DHA) plus androsterone was effected by thin-layer chromatography on silica-gel-G. The plate was developed for 2 hr. in a continuous elution tank in the system pentane:ether (4:1), which removes 'lipid-like' material to the solvent front area of the plate without moving steroids from the origin and gives much more reproducible migration of steroids when the plate is subsequently developed for 2 hr. in a continuous elution tank, using the system benzene:ethyl acetate (60:40). The plate

Recent in-vivo studies made by Deshpande, Jensen, Carson, Bulbrook & Doouss (1970) concerned with the synthesis of androgens by the human adrenal gland have again emphasized the equivocal nature of the results available on this subject. The present communication describes how results contrary to those obtained in vivo were derived from investigations in vitro: this prompts us to suggest that further studies are necessary on the control of androgen production. Evidence has been obtained (Ichii, Forchielli, Cassidy, Rosoff & Dorfman, 1962; Kase & Kowal, 1962; Ward & Grant, 1963) for the presence in various pathological types of human adrenal tissue of the enzyme systems necessary for the conversion of progesterone to adrenal androgens, while Deshpande et al. (1970) showed that in vivo, 17α-hydroxyprogesterone rather than dehydroepiandrosterone (DHA) is the more important precursor of androstenedione. On the other hand Cohn & Mulrow (1963) showed in both hyperplastic and neoplastic adrenal tissue

SUMMARY

3α-, 3β-, 11β-, 16β-, 17β- and 20β-hydroxysteroid dehydrogenases have been localized histochemically in the Leydig cells of prepubertal and adult human testes; 3α-, 16β- and 17β-hydroxysteroid dehydrogenases were present in the seminiferous tubules also. A similar pattern was found in cryptorchid testes. In addition 3β-sulphoxy steroids, including DHA sulphate, gave a good colour reaction in human Leydig cells. Testes from oestrogen-treated subjects had no histochemically demonstrable hydroxysteroid dehydrogenases and this applied also to infarcted testes. Testes from a case of Klinefelter's syndrome were found to lack 17β- and 20β-hydroxysteroid dehydrogenases in the Leydig cells. The biochemical significance of these results is discussed.