Transient expression in nonsteroidogenic mammalian cells of the rat wild type I and type II 3 beta-hydroxysteroid dehydrogenase/delta 5-delta 4-isomerase (3 beta-HSD) cDNAs shows that the encoded proteins, in addition to being able to catalyze the oxidation and isomerization of delta 5-3 beta-hydroxysteroid precursors into the corresponding delta 4-3-<em>ketosteroids</em>, interconvert 5 alpha-dihydrotestosterone (DHT) and 5 alpha-androstane-3 beta,<em>17</em> beta-diol (3 beta-diol). When homogenate from cells transfected with a plasmid vector containing type I 3 beta-HSD is incubated in the presence of DHT using NAD+ as cofactor, a somewhat unexpected metabolite is formed, namely 5 alpha-androstanedione (A-dione), thus indicating an intrinsic androgenic <em>17</em> beta-hydroxysteroid dehydrogenase (<em>17</em> beta-HSD) activity of this 3 beta-HSD isoform. Although the relative Vmax of <em>17</em> beta-HSD activity is 14.9-fold lower than that of 3 beta-HSD activity, the Km value for the <em>17</em> beta-HSD activity of type I 3 beta-HSD is 7.97 microM, a value which is in the same range as the conversion of DHT into 3 beta-diol which shows a Km value of 4.02 microM. Interestingly, this <em>17</em> beta-HSD activity is highly predominant in unbroken cells in culture, thus supporting the physiological relevance of this "secondary" activity. Such <em>17</em> beta-HSD activity is inhibited by the classical substrates of 3 beta-HSD, namely pregnenolone (PREG), dehydroepiandrosterone (DHEA), delta 5-androstene-3 beta,<em>17</em> beta-diol (delta 5-diol), 5 alpha-androstane-3 beta,<em>17</em> beta-diol (3 beta-diol) and DHT, with IC50 values of 2.7, 1.0, 3.2, 6.2, and 6.3 microM, respectively. Although dual enzymatic activities have been previously reported for purified preparations of other steroidogenic enzymes, the present data demonstrate the multifunctional enzymatic activities associated with a recombinant oxidoreductase enzyme. In addition to its well known 3 beta-HSD activity, this enzyme possesses the ability to catalyze DHT into A-dione thus potentially controlling the level of the active androgen DHT in classical steroidogenic as well as peripheral intracrine tissues.

The circadian periodicity of adrenal function in patients with congenital virilizing adrenal hyperplasia (CAH) was examined by measuring the urinary <em>17</em>-<em>ketosteroids</em>, <em>17</em>-hydroxycorticosteroids, sodium, and potassium. Patients with the salt-losing and the non-salt-losing types were studied with and without treatment. Cosine curves were fitted to the data by the least-squares method to determine the mesors, amplitudes, and acrophases of the variable for each patient. The data reveal distinct circadian rhythms for all variables measured whether or not the patient was receiving treatment. The acrophases for <em>17</em>-<em>ketosteroids</em> and <em>17</em>-hydroxycorticosteroids were between 1500 and 1800 h. These acrophases are about 6 h later than those for normal subjects. The treatment on a fixed daytime schedule for many years may have shifted the natural rhythm.

Cochliobolus lunatus <em>17</em>beta-hydroxysteroid dehydrogenase (<em>17</em>beta-HSD) is pluripotent for several steroidal and nonsteroidal substrates. In the presence of NADPH the enzyme was found to reduce 3-keto groups of 4,5-dihydro steroids, 20-keto groups, and most efficiently, <em>17</em>-keto groups of steroidal substrates. In addition, several quinones were accepted and found to be even better substrates as steroids due to their higher affinity for the enzyme-coenzyme complex and faster conversion of the enzyme-coenzyme-substrate complex into the corresponding products. As suggested by the competition studies quinones and <em>17</em>-<em>ketosteroids</em> are converted by the same active center of the enzyme. For all tested substrates, the equilibrium ordered mechanism was established with NADPH binding first to the enzyme. According to our knowledge, the investigated <em>17</em>beta-HSD is the first known fungal pluripotent enzyme of this type.

An adrenocortical adenoma associated with adrenogenital syndrome in a two-year-old boy was investigated light and electron microscopically. Urinary <em>17</em>-<em>ketosteroid</em> excretion was considerably elevated and unresponsive to dexamethasone administration. The level returned to normal after surgical removal of the tumour. Adenomatous cells display striking cellular and nuclear pleomorphism. Megalocytes with huge nuclei and nucleoli frequently occur. Deep cytoplasmic indentations cause nuclear pseudoinclusions and bizarre shape of the nuclei. True nuclear inclusions are also seen, as well as nuclear fragmentation. Cytoplasmic organelles show striking morphological alterations. Mitochondria with lamellar and tubular cristae are transformed into round or ovoid organelles of vesicular type. Their internal compartment is reduced, matrix material increases relatively, and mitochondrial inclusion bodies develop. Mitochondrial inclusions are identified as corresponding to fuchsinophil (siderophil or argyrophil) granules seen in the light microscope. Their staining properties indicate their glycoprotein nature. Vesicular profiles of smooth endoplasmic reticulum predominate and stacks of rough endoplasmic reticulum are transformed into tubules and vesicles. In Golgi regions, only vesicular elements are enriched. Lipid droplets are scarce. It was not possible to demonstrate histochemically catalase activity in microbodies. Dense bodies only occur in small, undifferentiated tumour cells. Multivesicular bodies, autophagosomes and residual bodies are rare. Lipofuscin is absent. Tumour cells are thought to derive from a population of undifferentiated cells ("germinative tumour cells"). Their morphological features and organelle equipment during a hypothetical course of differentiation and following dedifferentiation is described and discussed with respect to exceeding androgen synthesis.

The present study compares the effects on sleep and the subsequent period of wakefulness of delaying bedtime of 2 h or advancing rising time by 2 h in subjects clearly differentiated by morningness or eveningness in their circadian rhythms. Twelve young healthy good sleepers, six morning types (MT) and six evening types (ET), were selected. The data obtained from the second 24 h (night and day) with delayed bedtime (DB) and advanced rising time (AR) were compared with those obtained in the reference condition (R) with normal sleep schedules. Sleep was recorded polygraphically and rectal temperature was continuously monitored during the nights and during the day following the second night of each condition. Subjective estimations of alertness, performance tasks and urinary steroids were analysed. Early rising appeared to be more disturbing than a late bedtime. The second shortened night showed fewer characteristics of recovery sleep in AR than in DB. The decrease in self rated alertness was a function both of the type of condition (DB or AR) and of the morning-evening typology of the subject. The largest decrease was observed in AR and in the ET subjects. AR also resulted in the most pronounced decrease in performance tasks and in an increase in urinary <em>17</em> <em>ketosteroids</em> without changes in the <em>17</em> hydroxy-corticosteroids. The effects on rectal temperature were limited to short periods after bedtime in DB and rising time in AR.

In terms of adaptability, unlike inanimate objects, living organisms exist in a dynamic balance between "wear and tear" and "repair and recovery". We regarded <em>17</em>-hydroxycorticosteroids (<em>17</em>-OHCS) as a compound related to tissue "wear and tear" (Hans Selye) and sought for a compound related to tissue "repair and recovery". This led us to the discovery of <em>17</em>-<em>ketosteroid</em> sulfates (<em>17</em>-KS-S) in urine. Elderly persons, unlike young adults, show low levels in <em>17</em>-KS-S and little diurnal changes. In an elderly person <em>17</em>-KS-S can decrease on significant life events (e.g. a spouse's death) and remain at low levels for a long time. Elderly persons with frailty need to improve their lifestyle (meals, exercise, rest, sleep, etc.) qualitatively and quantitatively to adapt themselves to stress adequately. Increased <em>17</em>-KS-S levels were to be related to improvement in lifestyle.