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Radioimmunoassay of androsterone and androsterone-3-sulfate in plasma.

Details of a sensitive and specific radioimmunoassay for androsterone (1) and androsterone sulfate in plasma have been presented. Benzene extracts of plasma were chromatographed on alumina to isolate the androsterone fraction either (a) directly after extraction (A) or (b) after solvolysis (AS). Following treatment with rabbit anti-A-17-BSA, antibody bound steriod was precipitated by ammonium sulfate. Androsterone concentrations in normal male plasma averaged 57 +/- 24 (S.D.) ng/dl, range 35-135 ng/dl and for normal women, 44 +/- 21 (S.D.) ng/dl, range 18-98 ng/dl. Androsterone sulfate concentrations were: males 55 +/- 28 mug/dl (range 10-114 mug/dl); premenopausal females 52+/- 31 mug/dl (range 16-318 mug/dl).

Adolescent

Capillary gas chromatography with chemical ionization negative ion mass spectrometry in the identification of odorous steroids formed in metabolic studies of the sulphates of androsterone, DHA and 5alpha-androst-16-en-3beta-ol with human axillary bacterial isolates.

The products of metabolism of the sulphates (0.5 micromol/l) of androsterone, dehydroepiandrosterone (DHA) and 5alpha-androst-16-en-3beta-ol have been investigated after incubation with 72 h cultures of human axillary bacterial isolates for 3 days at 37 degrees C. The medium used, tryptone soya broth (TSB), contained yeast extract and Tween 80. The isolates used were Coryneform F1 (known previously to metabolize testosterone and to be involved in under-arm odour (UAO) production, i.e. UAO +ve), Coryneform F46 (inactive in both the testosterone metabolism and UAO tests, i.e. UAO -ve) and Staphylococcus hominis/epidermidis (IIR3). Control incubations of TSB alone, TSB plus each of the steroid sulphates and TSB plus each of the bacterial isolates were also set up. After termination of reactions and addition of internal standards, 5alpha-androstan-3beta-ol and 5alpha-androstan-3-one (50 ng each), extracted and purified metabolites were subjected to combined gas chromatography-mass spectrometry with specific ion monitoring. Steroidal ketones were derivatized as their O-pentafluorobenzyl oximes; steroidal alcohols (only androst-16-enols in this study) were derivatized as their tert-butyldimethylsilyl ethers. Analysis was achieved by negative ion chemical ionization mass spectrometry for the pentafluorobenzyl oximes at [M-20]- and electron impact positive ion mass spectrometry for the tert-butyldimethylsilyl ethers at [M-57]+. The incubation broth contained two compounds which had gas chromatographic and mass spectrometric properties identical to those of DHA and 4-androstenedione. It was not possible, therefore, to show unequivocally that DHA sulphate (DHAS) was converted microbially into DHA, although this is implied by the finding of small quantities of testosterone and 5alpha-dihydrotestosterone in incubations with F1. With androsterone S, no free androsterone was recorded and only very small (5 pg or less) amounts of testosterone. Two odorous steroids, androsta-4,16-dien-3-one and 5alpha-androst-2-en-17-one (Steroid I) were formed (mean quantities 40 and 45 pg, respectively). The sulphate of 5alpha-androst-16-en-3beta-ol was metabolized with F1 into large quantities of the odorous steroids, 5alpha-androst-16-en-3-one and Steroid I. In addition, much smaller quantities of androsta-4,16-dien-3-one were formed. In contrast, incubations of DHAS with F46 resulted in no metabolites except, possibly, DHA, but the sulphate moiety of androsterone S was also cleaved to yield the free steroid together with large amounts of Steroid I. In incubations of DHAS and androsterone S with F1, no 16-unsaturated steroids were formed, although 5alpha-androst-16-en-3beta-yl S was de-sulphated and the free steroid further metabolized. No evidence was obtained for androst-16-ene metabolism in incubations with F46. In incubations with S. hominis/epidermidis (IIR3), androsterone S was converted into androsterone and, in high yield, to Steroid I plus some 5alpha-androst-16-en-3-one. Both DHAS and androsterone S were converted into androst-16-enols. Sulphatase activity was also manifested when 5alpha-androst-16-en-3beta-yl S was utilized as substrate with IIR3, large quantities of Steroid I and 5alpha-androst-16-en-3-one being formed, together with further metabolism of androst-16-enes. In view of the fact that both DHAS and androsterone S occur in apocrine sweat, the metabolism of these endogenous substrates by human axillary bacteria to several odorous steroids may have important implications in the context of human odour formation.

Actinomycetales

Large deletion of androsterone UDP-glucuronosyltransferase gene in the inherited deficient strain of Wistar rats.

LA Wistar rats have a deficiency of androsterone UDP-glucuronosyltransferase (UDPGT) and are present in Wistar rat colonies around the world. In order to clarify the molecular mechanism of the deficiency, androsterone UDPGT cDNA clone, pGT2 was isolated from rat liver cDNA library and was digested with restriction enzymes to afford three probes for Northern and Southern blot analyses in HA (normal), heterozygous LA and LA Wistar rats. In Northern blot analysis, androsterone UDPGT mRNA was totally absent in LA Wistar rat liver. Southern blot analysis suggested a large deletion of androsterone UDPGT gene in the rats. Genomic DNA amplifications with synthetic primers which have nucleotide sequences corresponding to the 5'-region of androsterone UDPGT cDNA, suggested that androsterone UDPGT gene has exon 1 with a length of some 700 bp and that this exon is deleted in LA Wistar rats. Based on these lines of evidence, it is concluded that the large portion of androsterone UDPGT gene is deleted in LA Wistar rats, which results in the absence of androsterone UDPGT mRNA and consequently the corresponding enzyme protein.

Animals

Genetic deficiency of androsterone UDP-glucuronosyltransferase activity in Wistar rats is due to the loss of enzyme protein.

Hepatic microsomal UDP-glucuronosyltransferases towards androsterone and testosterone were purified by chromatofocusing and UDP-hexanolamine affinity chromatography in Wistar rats which had genetic deficiency of androsterone UDP-glucuronosyltransferase activity. In rats with the high-activity phenotype, androsterone (the 3-hydroxy androgen) UDP-glucuronosyltransferase was eluted at about pH 7.4 and had a subunit Mr of 52 000, whereas testosterone (the 17-hydroxy steroid) UDP-glucuronosyltransferase was eluted at about pH 8.4 and had a subunit Mr of 50 000. The transferase that conjugates both androsterone and testosterone was eluted at about pH 8.0, had subunit Mr values of 50 000 and 52 000, and appeared to be an aggregate or hybrid of androsterone and testosterone UDP-glucuronosyltransferases. In rats with the low-activity phenotype, androsterone UDP-glucuronosyltransferase was absent, whereas testosterone UDP-glucuronosyltransferase was eluted at around pH 8.5, with a subunit Mr of 50 000.

Androsterone

Studies on the genetic linkage of bilirubin and androsterone UDP-glucuronyltransferases by cross-breeding of two mutant rat strains.

Gunn rats, which have defects in bilirubin and 4-nitrophenol UDP-glucuronyltransferases (GT), were crossed with LA Wistar rats with a defect in androsterone GT. The F1 hybrids showed normal GT activities towards androsterone, bilirubin and 4-nitrophenol, demonstrating that Gunn and LA ('low activity') Wistar rats inherit a homozygous dominant trait for androsterone GT and bilirubin GT respectively. The F2 progeny showed four different combinations of bilirubin and androsterone GT activities: defects in both GT activities, a single defect in bilirubin GT activity, a single defect in androsterone GT activity and two normal GT activities. They were segregated in the approximate ratio of 1:3:3:9, which is compatible with Mendel's Principle of Independent Assortment. These results provide evidence that androsterone GT and bilirubin GT are located on different chromosomes. In the F2 generation, defective bilirubin and 4-nitrophenol GT activities were not segregated, indicating that these two mutant genes are closely linked on the same chromosome.

Androsterone

Metabolism of androsterone and 5 alpha-androstane-3 alpha,17 beta-diol in human lung tissue and in pulmonary endothelial cells in culture.

The metabolism of [3H]androsterone and [3H] 5 alpha-androstane-3 alpha,17 beta-diol ( [3H] 3 alpha-diol) was studied in slices of human lung tissue and cultures of human pulmonary artery endothelial cells. Lung tissue metabolized [3H]androsterone (0.25 microM) to 5 alpha-androstane-3,17-dione (30.3 pmol 100 mg-1 tissue h-1), isoandrosterone (0.7 pmol 100 mg-1 tissue h-1), 5 alpha-dihydrotestosterone (5 alpha-DHT; 0.1 pmol 100 mg-1 tissue h-1), 3 alpha-diol (0.1 pmol 100 mg-1 tissue h-1), and two polar metabolites. Pulmonary arterial endothelial cells produced the same metabolites of [3H]androsterone (0.083 microM), with the exception of the polar compounds [5 alpha-androstane-3,17-dione (1.3 pmol mg-1 protein h-1), isoandrosterone (0.1 pmol mg-1 protein h-1), 5 alpha-DHT (0.2 pmol mg-1 protein h-1), and 3 alpha-diol (0.2 pmol mg-1 protein h-1)]. Thus, the principal metabolite of [3H]androsterone in both lung tissue and endothelial cells was 5 alpha-androstane-3,17-dione. Human lung tissue metabolized [3H]3 alpha-diol (0.28 microM) to 5 alpha-DHT (8.8 pmol 100 mg-1 tissue h-1), androsterone (2.2 pmol 100 mg-1 tissue h-1), 5 alpha-androstane-3,17-dione (0.8 pmol 100 mg-1 tissue h-1), isoandrosterone (0.1 pmol 100 mg-1 tissue h-1), and four polar metabolites (0.2 pmol 100 mg-1 tissue h-1). 5 alpha-DHT was the principal metabolite of [3H]3 alpha-diol within the first hour of incubation, but the concentration of this androgen declined thereafter to 3.6 pmol 100 mg-1 tissue after 4 h of incubation. This decline was correlated with increased 5 alpha-androstane-3,17-dione synthesis (6.7 pmol 100 mg-1 tissue 4 h-1). Androsterone formation from [3H]3 alpha-diol, however, was linear with time of incubation for 4 h (8.9 pmol 100 mg-1 tissue 4 h-1). The formation of these products demonstrates that the principal 5 alpha-reduced-C19-steroid-metabolizing enzymes in human lung are 3 alpha-hydroxysteroid oxidoreductase.

Adolescent

Androsterone long chain fatty acid esters in human breast cyst fluid.

We reported previously that incubation of [3H] androsterone in homogenates of human breast tumor resulted in production of long chain fatty acid esters of androsterone (A-LCFE). To identify the individual A-LCFE, breast tumor homogenates were incubated with androsterone, then submitted to solvent extraction, Celite chromatography, high pressure liquid chromatography and OH- negative chemical ionization mass spectrometry. The (M-1)-ions of the oleate, linoleate, palmitoleate, palmitate, arachidonate, and stearate esters of androsterone were produced. The first 3 cited unsaturated esters accounted for over 90% of the total. Since fibrocystic disease of the breast is a reported risk factor for the development of breast cancer, breast cyst fluids were analyzed for A-LCFE as part of an overall program to relate endocrine profiles in cyst fluid to the incidence of cancer. Breast cyst fluids were analyzed for total A-LCFE by a method involving solvent extraction, saponification, purification of the liberated androsterone, and then quantification of the steroid by RIA. The 10 fluids analyzed contained 0.52-3.79 ng/ml fatty acid esters, measured as androsterone. In 4 of these samples, the individual A-LCFE were analyzed by mass spectrometry. As in the incubation study, the unsaturated fatty acid esters predominated. In 3 samples, palmitoleate and in 1 sample, oleate predominated. The palmitate varied from undetectable to 25% of the total. The divergent total concentrations and profiles of A-LCFE indicate potential parameters for correlations with the subsequent course of fibrocystic disease of the breast.

Androsterone

The molecular basis of the inherited deficiency of androsterone UDP-glucuronyltransferase in Wistar rats.

A major UDP-glucuronyltransferase isoenzyme in rat liver (51 kDa), corresponding to androsterone glucuronidating activity, has been identified by immunoblot analysis. This isoenzyme is absent from Wistar rats exhibiting the low androsterone (LA) UDP-glucuronyltransferase activity exhibiting the low androsterone (LA) UDP-glucuronyltransferase activity phenotype. Northern blot analysis of total RNA from normal and androsterone glucuronidation deficient Wistar rats demonstrated that the mRNA encoding this protein was not synthesised. Differences in restriction fragment length observed on Southern blotting of genomic DNA from LA Wistar rats indicate that this inherited deficiency is the result of a deletion in the androsterone UDP-glucuronyltransferase gene.

Androsterone

Glucosiduronidation and esterification of androsterone by human breast tumors in vitro.

The metabolism of 3H-androsterone was studied in homogenates (fortified with uridine 5'-diphosphoglucuronic acid and adenosine 3'-phosphate 5'-phosphosulfate) of eighteen breast tumors, one muscle underlying the primary breast carcinoma and metastatic axillary lymph nodes from a patient with suspected primary breast cancer. The major metabolites identified were less polar than androsterone. On saponification these lipoidal derivatives afforded androsterone as the only product (3 to 48%). Unmetabolized androsterone and lesser quantities of epiandrosterone, 5 alpha-androstane- alpha, 17 beta-diol and 5 alpha-androstane-3,17-dione comprised the free steroid fraction. Androsterone glucosiduronate was isolated (0.17-4.1%) from weight breast tumor homogenates and from the node tissue incubation (17%). There was no apparent correlation between glucuronyltransferase activity and histopathology or estrogen receptor content.

Adenofibroma

Glucosiduronidation of androsterone by human breast tumors in vitro in relation to the progesterone receptor content.

Homogenates of human breast tumors were incubated with 3H-androsterone and the percentage conversions to androsterone glucosiduronate were determined. In addition, separate portions of the tumors were analyzed for estrogen receptor (ER) and progesterone receptor (PR) to see whether conjugation and receptor content could be correlated. Sixteen of thirty-two tumor homogenates formed androsterone glucosiduronate (0.03-5.9%) from androsterone. There was no correlation between ER content and glucuronyltransferase activity. Considering the twenty-six malignant mammary tumors, of the fifteen PR positive types, five (one-third) formed the conjugate. In contrast, almost two-thirds (seven of eleven) of the PR negative tumors formed androsterone glucosiduronate. These correlations indicate a trend, but not of statistical significance.

Androsterone

Developmental alteration of hepatic UDP-glucuronosyltransferase and sulphotransferase towards androsterone and 4-nitrophenol in Wistar rats.

Postnatal development of hepatic UDP-glucuronosyltransferase and sulphotransferase activities towards androsterone and 4-nitrophenol as well as cytochrome P-450 contents was studied in male and female Wistar rats. The rats with high and low UDP-glucuronosyltransferase activity towards androsterone were classified by the genotype of the parent animals. UDP-glucuronosyltransferase activity towards androsterone began rapidly to enhance after 30 days of age in the high-activity group, whereas the transferase activity remained low throughout in the low-activity group. Such a striking difference was not observed in UDP-glucuronosyltransferase activity towards 4-nitrophenol, sulphotransferase activity towards androsterone and 4-nitrophenol, and cytochrome P-450 contents. Sex-based difference in the sulphotransferase activity was marked after 30 days of age. Sulphotransferase activity towards androsterone was much higher in adult females than in adult males, whereas higher sulphation activity towards 4-nitrophenol was found in adult males. The results also indicate that the low level of the UDP-glucuronosyltransferase activity did not lead to compensatory stimulation of the sulphotransferase activity.

Age Factors

Serum androsterone levels in children.

Serum androsterone was measured by radioimmunoassay in 79 girls and 80 boys aged between six months to sixteen years. In boys, androsterone levels were found to be low until the age of 12 years and then rapidly increased between the ages of 12-13 years. This increase of serum androsterone in boys seems to be related to the rapid increase of testosterone. On the other hand, in girls the androsterone levels were found to be low until the age of 10 years. However, from this age onwards, although individual values were variable, androsterone levels did not increase as rapidly as in boys but rather gradually with age which appeared to be influenced by the progressive increase of dehydroepiandrosterone (DHEA) in girls.

Adolescent

Identification and measurement of urinary estrone, estradiol-17 beta, estriol, pregnanediol and androsterone during the menstrual cycle of the orangutan.

Urinary estrone, estradiol-17beta, estriol, pregnanediol and androsterone were identified and measured during 3 menstrual cycles in 2 female orangutans. In 2 of the cycles, the animals excreted 1-8 mug/day estrone, 0.5-6 mug/day estradiol-17beta, 1-8 mug/day estriol, 20-206 mug/day pregnanediol and 120-522 mug/day androsterone during the first half of the menstrual cycle. In the second half of the cycle, corresponding values were 3-21 mug/day estrone, 2-10 mug/day estradiol-17beta, 1-9 mug/day estriol, 54-800 mug/day pregnanediol and 90-1158 mug/day androsterone. In 1 cycle, the estrogen values for the second half were considerably higher, possibly due to the animal becoming pregnant just before this study commenced. The values for estrone and estradiol-17beta are similar to those found in the human and chimpanzee menstrual cycle. The values for estriol were lower than in the human but higher than in the chimpanzee. Levels for urinary pregnanediol and androsterone were significantly lower than in the human. Variations during the menstrual cycle for estrone were characterized by a midcycle peak followed by a second peak in the luteal phase. No definite pattern was apparent for estradiol-17beta or estriol. Both urinary pregnanediol and androsterone levels were low during the first half of the cycle, started to rise just after midcycle, and showed a peak during the second half of the menstrual cycle.

Androsterone

The metabolism and 24-hour plasma concentrations of androsterone in man.

A radioimmunoassya for free androsterone permitting facile analysis of plasma taken at 20 min intervals over 24 h has revealed a curve of varying concentrations which formed a pattern similar to curves of cortisol and dehydroisoandrosterone, boht bein primary adrenal secretory products and the latter being the major precursor of androsterone. The mean of the average 24 h concentrationof androsterone in men was 55 +/- 14 ng/dl (n = 8). Such temporally related behavior requires rapid production and removal of both 17-ketosteroids, processes which have been confirmed by tracer studies where it has been shown that in a two compartment system, androsterone has a t1/2 of 25 +/- 9 min for the fast component and metabolic clearance rate of 4050 +/- 1315 L per day (n = 10). The data are in accord with an approximate production rate of androsterone which is consistent with values reported for its urinary excretion.

Androsterone