Chromatographic separation of estrone and 17 beta-estradiol conjugates on DEAE-Sephadex

Transfer of [3H]estrone-[35S]sulfate across guinea pig fetal membranes

The possible role of fetal membrane deconjugating activity in the movement of a charged steroid conjugate between fetal and maternal compartments was investigated. The ability of amnion and chorion laeve to transfer [3H]estrone-[35S]sulfate was assessed in both orientations of guinea pig tissue at 45 days and near parturition. While early amnion was impermeable, late tissue transferred approximately 50% (w/w) of the substrate in a bidirectional process that was non-saturable and independent of either deconjugation or ATP. Transfer across early chorion was similar to late amnion. Saturation curves from each tissue were superimposable, as were those of the time course. Transfer across both early and late chorion proceeded in the absence of deconjugation, with no effect of tissue orientation or ATP depletion. However, late chorion exhibited a decrease in estrone-sulfate transfer, as verified by concentration dependency and time course analyses, though transport across the tissue remained non-saturable. The results in amnion were congruous with the presence and absence of tight junctions in the epithelium of early and late tissue, respectively. However, sulfoconjugate transfer across early chorion proceeded in the presence of a paracellular barrier, suggesting specialized regulation of the transport process which extended late into gestation.

Transfer of steroidal and nonsteroidal compounds across guinea pig fetal membranes

Transfer of steroidal and nonsteroidal compounds across guinea pig amnion and chorion laeve was investigated as a function of stage of gestation, tissue orientation, steroid specificity, and molecular size. Each fetal membrane was examined at early and late stages of gestation, before and after pubic symphysis relaxation. Early amnion was impermeable to macromolecules and small charged molecules while [3H]estrone and [3H]pregnenolone were transferred, the latter depending on tissue orientation and involving conjugation at the basolateral interface. After symphysis dilation, amnion transferred all substrates tested with the exception of BSA; the molecular weight cutoff was approximately 5,000. Unlike amnion, early chorion transferred both free and conjugated steroids as well as inorganic sulfate. Transfer of estrone involved conjugation and depended on tissue orientation. Transfer of [3H]estrone-sulfate, [3H]estrone-glucuronide, and [3H]pregnenolone-sulfate was similar despite selective deconjugating activity toward estrone-sulfate. Near term, chorion was impermeable to inorganic sulfate and transfer of estrone-glucuronide depended on tissue orientation, involving deconjugation in the maternal to fetal direction. At no stage of gestation did chorion transfer macromolecules. These results suggest that the transfer of free and conjugated steroids across fetal membranes is differentially regulated by tissue, its stage of development, and direction of transfer.

Sulfation by guinea pig chorion and uterus: differential action towards estrone and estradiol

The activities of estrogen sulfotransferase, estrogen sulfatase and estradiol 17beta-dehydrogenase change considerably in the guinea pig uterine compartment during gestation. This study was undertaken to inquire if the chorion membrane could influence the pattern of estrogen resulting when substrates were applied to the fetal surface of the chorion while it was attached, late in gestation, to the uterine wall. This tissue system resulted in a differential handling of estrone and estradiol. Estrone was largely excluded from the tissue, remaining mainly in free steroidal form. Estradiol was considerably converted to its 3-sulfate which was mainly retained by the chorion. Parallel experiments with chorion and uterus separately failed to discriminate between the two substrates. Hydrolysis of estrone sulfate and estradiol 3-sulfate was similar in all three tissue systems. It appears that the interaction of chorion with uterus late in gestation causes a difference in tissue action towards the two steroid substrates of closely related structure. The results suggest a limitation in tissue uptake of estrone compared with estradiol, or a much greater sulfotransferase activity towards estradiol. Whole cytosols of late gestational chorion catalyzed sulfation of estradiol at about double the velocity of estrone. This may only partly account for the difference in the intact chorion-uterine tissue system.

Generation of estradiol within the pregnant guinea pig uterine compartment with special reference to the myometrium

Between about 50 and 58 days of gestation, the guinea pig chorion becomes attached in its entirety to the uterine wall, suggesting a facilitation of transfer of agents such as steroids between these tissues. At a time between 59 and 64 days, relaxation of the pubic symphysis starts, and anywhere from 5 to 8 days after that event delivery takes place. The present in vitro study was undertaken to evaluate estrone sulfate as a substrate for local production of estradiol, via the action of estrogen sulfatase and 17-hydroxysteroid dehydrogenase, in chorion, endometrium and myometrium taken at four distinct stages of gestation, as follows: 50 days, representing pre-chorion attachment to the uterus (stage 50); 1 or 2 days before pubic symphysis relaxation (minus 1 day, or -1 day); 1 day following relaxation (+1 day); and 1-2 days before delivery (late, or L). At these same stages, the metabolite patterns formed from estradiol were evaluated for endometrium and myometrium. Each of the tissues behaved somewhat differently. Overall hydrolysis of estrone sulfate by endometrium and myometrium exceeded that by chorion. Generation of free steroid from estrone sulfate increased 3-fold in chorion between stages 50 and -1 and during this period estradiol production from estrone sulfate increased 9-fold and continued to rise until delivery. Cytosolic estrogen sulfotransferase activity of chorion decreased 7-fold between stages 50 and -1. This suggested a tissue environment geared to producing potentially active estradiol. However, myometrium converted very little estrone into estradiol until just before delivery despite the facile formation of estrone from estradiol at stages -1, +1 and L. The control of estrogen metabolism by interaction of tissues in the uterus and by some form of enzyme regulation in these tissues suggests a possible role for locally produced estrogen in the stages leading up to parturition.

Estrogen sulfotransferase and 17 beta-hydroxysteroid dehydrogenase activities in guinea-pig chorion through gestation

Estrogen sulfotransferase (EST) activity measured under optimal in vitro conditions in the 105,000 g cytosols (HSS) of homogenized intrauterine tissues (amnion, chorion, endometrium, decidua basalis and placenta) from guinea-pigs at the 50th day of gestation indicated that the highest specific activity occurred in the chorion. EST activity in the chorion increased from day 34 (early gestation) to peak around day 45 (mid-gestation), before significantly decreasing around day 50 and further declining to barely detectable levels beyond day 60 (late gestation, the onset of parturition). 17 beta-Hydroxysteroid dehydrogenase (17 beta-HSD) activity in the chorion was almost completely membrane associated. The specific activity of the 17 beta-HSD reduction reaction in the 105,000 g pellet was 2.5-fold higher at mid-gestation than at late gestation, while the specific activity of the 17 beta-HSD oxidation reaction was 1.7-fold higher at mid-gestation as compared with late gestation. When intact pieces of chorion tissue from mid- and late gestation were incubated with 5 nM [3H]estradiol (E2), approx. 80% of the recovered free estrogen was E1 (estrone). Only chorion from animals at the onset of parturition were able to produce detectable amounts of E2 from 5 nM [3H]E1. Under the same experimental conditions the ratio of estradiol sulfate (E2S) to estrone sulfate (E1S) isolated from the media and methanol washes of late gestation chorion tissue was 3-4 times greater than for the day 45 tissue.

Estrogen sulfatase and steroid sulfatase activities in intrauterine tissues of the pregnant guinea pig

The possible role of intrauterine estrogen sulfatase and steroid sulfatase around the time of parturition in the guinea pig was investigated. [3H]Estrone sulfate or [3H]pregnenolone sulfate was incubated with intrauterine tissues. Estrogen sulfatase was found in placenta, endometrium, decidua basalis, amnion and chorion. The presence of steroid sulfatase was established in endometrium and decidua basalis but not in placenta or the fetal membranes. Examination of activities in early (days 32-35), mid (days 44-46) and late (within 5 days of parturition) gestation revealed no significant change in estrogen sulfatase specific activity in decidua basalis. However, in chorion and endometrium this activity was seen to increase approx. 12-fold (P less than 0.001) and 2.8-fold (P less than 0.001), respectively, from early to late gestation. In placenta, estrogen sulfatase activity appeared to increase 2.4-fold (P less than 0.001) and in amnion it decreased 2.8-fold (P less than 0.002). Steroid sulfatase activity in decidua basalis did not change during gestation, while activity in endometrium was found to increase by a factor of 5.3 (P less than 0.001), from early to late gestation. The increases, both in estrogen sulfatase activity in chorion, endometrium and placenta and in steroid sulfatase activity in endometrium, occurred primarily within the final 3 weeks of gestation. In contrast, the decrease in estrogen sulfatase activity in amnion occurred principally between the fifth and sixth weeks of gestation. Analysis of radiolabelled metabolites indicated that estradiol and progesterone could be produced via estrogen sulfatase and steroid sulfatase activities in certain tissues. Subcellular fractionation of tissues revealed that the greatest specific activity and total activity, in all cases, was associated with the 105,000 g pellet. Significant activity was also detected in the 750 and 10,000 g pellets but not in the 105,000 g supernatant. Radioimmunoassay of endogenous estradiol-17 beta (estradiol) in chorion extracts revealed a 6.3-fold increase in the hormone from mid to late gestation. Estradiol levels in endometrium and myometrium did not appear to change during this time. It was concluded that increased estrogen sulfatase activity in guinea pig chorion in late gestation occurs along with elevated levels of the hormone estradiol which may be important for parturition in this species.

Purification and some characteristics of an oestrogen sulphotransferase from guinea pig adrenal gland and its non-identity with adrenal pregnenolone sulphotransferase

An oestrogen sulphotransferase, active towards both oestrone and oestradiol, and of high specific activity, is present in cytosol prepared from adrenal glands of both sexes of English Shorthair and Hartley guinea pigs. The ovarian and testicular cytosolic activities of this enzyme are markedly low in comparison with the adrenal activity. The adrenal enzyme is distinct from an accompanying pregnenolone sulphotransferase as judged by f.p.l.c. gel filtration, chromatofocusing, and differences in activation brought about by the addition of thiol groups. The oestrogen sulphotransferase behaved as a 67 kDa protein on a Sephadex G100 column and as a 48 kDa protein on f.p.l.c. gel-filtration columns. Two forms of the enzyme with apparent pI values of 6.1 and 5.5 were eluted during f.p.l.c. chromatofocusing. Sequential salt fractionation, f.p.l.c. gel filtration and elution from an agarose-hexane-adenosine-3',5'-diphosphate affinity gel has resulted in a preparation which, when resubmitted to f.p.l.c. gel filtration, yields a considerably purified oestrogen sulphotransferase. When submitted to SDS/polyacrylamide-gel electrophoresis under reducing conditions, a main protein band of 34-36 kDa is observed. It is suggested that the enzyme may exist as a dimer in the cytosol.

Partial characterization of steroid sulfohydrolase and steroid sulfotransferase activities in purified porcine Leydig cells

Subcellular fractions of purified pig Leydig cells from 7 different animals have been investigated with respect to their abilities to catalyze the sulfation of several steroids and the hydrolysis of the sulfated forms of these same steroids. Considerable estrone sulfate sulfohydrolase of pH optimum 7.5 and high apparent Km was found to be concentrated in the 105,000 g pellet but no evidence was obtained, in any subcellular fraction, for the presence of any activity toward the 3-sulfate of pregnenolone, dehydroepiandrosterone (DHA) or delta 5-androstene-3 beta,17 beta-diol (androstenediol). Cytosolic sulfotransferase activity toward estrone, pregnenolone, DHA and androstenediol was present in each animal. The activity toward these 4 substrates was eluted from a gel filtration column as a single peak of apparent molecular weight 43 KDa. Upon chromatofocusing, a sharp estrogen sulfotransferase peak of apparent pI 6.1 and pH optimum 9.5, was clearly separated from the neutral steroid sulfotransferase which eluted over a more acidic pH range in a manner suggestive of the presence of several isozymes. This latter, which exhibited a wide pH optimum range between 6 and 8.5, was most active toward androstenediol, and least active toward pregnenolone. The estrogen sulfotransferase exhibited Michaelis-Menten kinetics (apparent Km = 4 microM). The neutral steroid sulfotransferase activity increased in velocity with increasing androstenediol or DHA concentration up to 1 microM beyond which considerable substrate inhibition occurred. It appears from these data that neutral steroid sulfates synthesized in the pig Leydig cell are not subject to enzymic desulfation in the same cells.

Separation of urinary metabolites of radiolabelled estrogens in man by HPLC

A method to separate radiolabelled urinary estrogens by high performance liquid chromatography (HPLC) is described. Estrogen glucuronides were isolated from the urine of women receiving bolus injections of [4-14C]estrone or [4-14C]estradiol by adsorption on Sep-Pak C18 cartridges and subsequent DEAE Sephadex A25 column chromatography. Following enzyme hydrolysis, free estrogens were extracted and concentrated in methanol-water containing ascorbic acid. HPLC was performed either by C18 reversed phase chromatography using different concentrations of acetonitrile with or without tetrahydrofurane in phosphate buffer or methanol-water as mobile phases, or on a Diol column using chloroform-isooctane-n-hexane or isopropanol-isooctane-n-hexane as mobile phases. 3H-labelled estrogens were added as internal standards, and urinary [14C]estriol, [14C]estradiol and [14C]estrone concentrations could be measured with an interassay coefficient of variation less than 5%. Interassay coefficients of variation for [14C]2-hydroxyestriol, [14C]16 alpha-hydroxyestrone, [14C]2-hydroxyestradiol, [14C]2-hydroxyestrone and [14C]2-methoxyestrone were between 5 and 10%, while interassay coefficients of variation for [14C]4-hydroxyestrone was 14.6%. Recovery of the unstable catechol estrogen 2-hydroxyestrone was comparable to the recovery of the other estrogen metabolites, due to the addition of ascorbic acid throughout the different pre-chromatographic steps. Our method is suitable for the separation of the major labelled estrogen metabolites found in human urine following administration of radiolabelled estrone or estradiol.

Heterogeneity of guinea pig chorion and liver estrogen sulfotransferases

The presence of two forms of estrogen sulfotransferase (EST) in 105,000 g cytosols of guinea pig chorion and liver has been established by chromatofocusing via a fast protein liquid chromatographic (FPLC) procedure. The chorion EST forms were eluted at pH 6.2 and 5.4, and the liver forms at 6.1 and 5.3. Each has been further purified by an affinity column step using Agarose-hexane-adenosine-3',5'-diphosphate (PAP-Agarose) gel to achieve up to 386-fold and 77-fold specific activity (SA) increases over cytosol for chorion and liver, respectively. The most highly purified preparations were extremely unstable unless protected by the addition of serum albumin of high purity. Each EST form exhibited an estimated molecular weight of 48-52 KDa by FPLC gel filtration and each acted upon both estrone (E1) and estradiol (E2). Each of these steroids inhibited sulfation of the other. A departure from Michaelis-Menten kinetics occurred, particularly in the case of chorion EST, at steroid substrate concentrations above 0.1-0.15 microM. E2 caused strong substrate inhibition of the most highly purified chorion EST. Chorion EST possessed considerable affinity for E1 and E2.

Characteristics and behavior during partial purification of estrogen sulfotransferase of guinea pig liver and chorion

Some characteristics of estrogen sulfotransferases from guinea pig liver and chorion were compared. Liver cytosolic activity was stimulated 10-fold by 25 mM monothiolglycerol and 2-fold by 15 mM MgCl2 or CaCl2, similar to that found previously for chorion. Liver and chorion activities were each eluted as a single peak from fast protein liquid chromatography (FPLC) gel filtration columns at apparent molecular weights of 52,300 and 50,000, respectively. Each was eluted during FPLC anion exchange under single, wide peaks with low recoveries. Liver sulfotransferase activity was eluted from Affi-gel Blue columns in the form of several peaks whereas the chorion activity behaved as a single species. The enzymes from both tissues, when partially purified by gel filtration followed by anion exchange, acted upon estrone and estradiol at the 3-position but activity toward dehydroepiandrosterone and testosterone was minimal or undetectable. Affi-gel Blue chromatography followed by FPLC gel filtration resulted in increases in specific activity of 26- and 90-fold for liver and chorion, respectively. Both enzymes were eluted from agarose-hexane-adenosine 3',5'-diphosphate (PAP-agarose) columns as single peaks. Average increases in specific activity for this column step were 40-fold and 96-fold for the entire eluted peaks of liver and chorion enzyme, respectively. Individual fractions from the PAP-agarose column indicated a specific activity increase of as much as 60-fold for liver and 208-fold for chorion. These latter were markedly unstable and it was not possible to obtain further purification by additional steps. Velocity versus substrate concentration curves for the partially purified enzymes showed complex kinetics, particularly with estradiol as substrate.

Behavior of mouse placental and uterine estrogen sulfotransferase during chromatography and other procedures

The estrogen sulfotransferase activity of high-speed supernatants of mouse placenta and uterus behaves on conventional and high-performance liquid chromatographic gel filtration as an enzyme species with a molecular weight of the order of 30 000. This is so whether the cytosols are freshly prepared or have been stored at -20 degrees C before chromatography. The presence of thiol groups or EDTA has no effect on the elution pattern. The partially purified enzyme is extremely unstable and is poorly recovered by (NH4)2SO4 fractionation. Some stabilization can be achieved in the presence of 0.1 microM estradiol. Chromatofocusing of cytosols results in the elution of one or two sulfotransferase peaks, depending upon experimental conditions such as the presence or absence of thiol groups. These peaks act upon both estrone and estradiol as substrates. Chromatofocusing by fast protein liquid chromatography (FPLC) in the absence of thiol groups results in the elution of one sulfotransferase peak whose activity can be detected only when thiol groups are present during enzyme assay.

Development and characteristics of an oestrogen sulphotransferase in placenta and uterus of the pregnant mouse. Comparison between mouse and rat

The mouse placenta possesses a soluble oestrogen sulphotransferase activity which increases markedly from at least 12 days of gestation until term. At about 16 days of gestation, a similar activity is found in the uterus. This activity also increases until term and disappears rapidly post partum. The uterine enzyme activity appears to require the presence of the foetal unit for its onset, since unoccupied horns, whether their endometrial stromal cells are differentiated to decidual cells or not, are essentially devoid of it. Uterine cytosols from non-pregnant mice are also inactive in this respect. In late gestation, the uterine sulphotransferase is confined to the decidua basalis, the areas to which the placentas are attached. The sulphotransferase(s) of placenta and uterus has an absolute requirement for 3'-phosphoadenosine 5'-phosphosulphate, and possesses little activity in the absence of exogenous thiol groups. Stimulation is also seen in the presence of Mn2+, Mg2+ or Ca2+. Oestrone and oestradiol, and to a lesser degree oestriol, are substrates for the enzyme(s), whereas testosterone, cortisol and dehydroepiandrosterone are not. Oestrone and oestradiol at higher concentrations (1.0-1.5 microM) completely inhibit the enzyme(s). These enzymes could play a role in altering tissue concentrations of active oestrogens during gestation in the mouse. Oestrogen sulphotransferase activity is low or absent in reproductive tissues of the pregnant rat.

Estrogen sulfotransferase activity in guinea pig uterus and chorion

An estrogen sulfotransferase (ST) is detectable in high speed supernatants of pregnant guinea-pig uterus and shows maximum activity between about 47 and 55 days of gestation, with a decrease toward term. No appreciable activity was apparent in the non-pregnant state or before at least 43 days of pregnancy. A considerably higher ST activity is present in chorion as early as 30 days of gestation, and this also decreases toward term. The two ST's exhibit similar KM (0.1-0.13 microM with estrone as substrate) and pI (5.8) values, as well as similar specificities. Estradiol-17 beta and estriol are sulfurylated 82 and 6% that of estrone at equimolar concn. Neither p-nitrophenol nor several neutral steroids are substrates for the enzymes. Enzyme activity is poorly expressed in the absence of thiol groups, the presence of monothioglycerol stimulating uterine and chorion enzymes by 5- and 15-fold, respectively. Stimulation is also observed in the presence of Mg2+, Ca2+ or Mn2+. Chromatofocusing on a poly buffer ion-exchanger from pH 7.4 to 4.0 resulted in elution of a sharp peak of enzyme activity, at pH = 5.8, from both tissues provided that the eluting buffer contained thiol groups and 0.25 M sucrose. This single step resulted in at least a 35- to 100-fold increase in specific activity. The partially purified enzyme from chorion exhibited a KM for estrone of 0.13 microM.

Enzymatic detection of urinary conjugated steroids after gel chromatography

An enzymatic detection method is described for urinary conjugated steroids after chromatographic fractionation with Sephadex G-25. The principle of the method is as follows. Part of a 24-h urine sample, (1-2 ml of urine) is applied directly, to a short column of Sephadex G-25 and eluted with acetate buffer solution. Steroid conjugates in each fraction are hydrolyzed with steroid sulfatase--beta-glucuronidase. After enzymatic hydrolysis, an enzymatic color development reagent for steroids, either 3 alpha-hydroxysteroid dehydrogenase or 3 beta-hydroxysteroid oxidase, are added and the dye formed is measured spectrophotometrically. Excretion patterns of steroid-3 beta-sulfates, and steroid-3 alpha-glucuronides and steroid-3 alpha-sulfates ae shown with some patients' samples. A precision of the assay values for steroid-3 alpha-glucuronide, steroid-3 alpha-sulfate and steroid-3 beta-sulfates in urine samples and assay values for normal subjects are also studied. This simple enzymatic method for detecting the excretion patterns of urinary conjugated steroids may have a diagnostic value for clinical tests.

A reliable radiochromatographic assay technique for hepatic microsomal 16 alpha-hydroxylase activity towards oestrone 3-sulphate. Comparison between pigmented and non-pigmented mature guinea pigs

A reliable procedure for the assay of liver microsomal 16 alpha-hydroxylation of oestrone 3-sulphate has been developed for the guinea pig. It is based on the rapid, quantitative separation of oestradiol and oestriol by Sephadex LH-20 columns after the chemical reduction and enzymic hydrolysis of the incubation products. Microsomal preparations and incubation conditions that optimized 16 alpha-hydroxylation of oestrone 3-sulphate were employed. Under these circumstances, reduction of the substrate at C-17 and hydrolysis of the sulphate were minimized. Conditions were established that yielded reaction linearity with respect to time and microsomal concentration. This hydroxylation had an absolute requirement for NADPH, which could not be satisfied by NADH. Apparent Km values for oestrone 3-sulphate and NADPH, under the conditions used, were 14 microM and 0.17 mM respectively. 16 alpha-Hydroxylase activity was present in the liver microsomal fraction from heavily pigmented, female English Shorthaired guinea pigs. Much lower activity was detected in mature pigmented males and albino females. No activity could be demonstrated in mature, albino males.

Steroid estrogen conjugates in hens' urine II. Identifications of some minor conversion products of intramuscularly injected [4(-14C)]estrone

[4(-14C)]Estrone was injected intramuscularly into two mature laying Rhode Island Red hens. Radioactive steroids and steroid conjugates recovered from the urine on Amberlite XAD-2 columns were fractionated on columns (100 cm) of DEAE-Sephadex A-25 by NaC1 gradients. The presence of the following were confirmed, the figures in brackets indicating average proportions as per cent of total radioactivity recovered after Sephadex column chromatography:-the 3-beta-glucuronides of estrone (10.9) and of estradiol-17alpha plus estradiol-17beta(9.8): the 17-beta-glucuronides of estradiol-17alpha plus estradiol-17beta (2.1); the 3-sulfates of estrone (14.5) and of estradiol-17alpha plus estradiol-17beta(27.4); and the disulfates of estradiol-17alpha plus estradiol-17beta (2.3). The following additional conjugates were identified:-a beta-glucuronide of 16-epiestriol (0.2) and a beta-glucuronide of 16-keto-estradiol-17beta (0.2); the 3-sulfates of 16-epiestriol (1.4), of 17-epiestriol (0.9), of 16,17-epiestriol (0.7), of 16-keto-estradiol-17beta (1.1), and of 2-methoxyestrone (0.7). Some evidence was obtained for the presence of 16,17-epoxy-estratrienol-3-sulfate (1.9).

Separation of estrogen conjugates by high pressure liquid chromatography

High pressure liquid chromatography using a prepacked commercial strong anion exchanger column (mu Partisil 10 SAX, 25 cm x 4.6 mm) was used to separate a mixture of eight estrogen conjugates. Chromatographic conditions using a 0.01 M potassium phosphate or 0.1 M NaCl as solvent in the isocratic mode are described for the separation of estrone glucosiduronate, 17beta-estradiol-3-glucosiduronate, 17beta-estradiol-17-glucosiduronate, estriol-3-glucosiduronate, estriol-16alpha-glucosiduronate, estriol-17-glucosiduronate, estrone sulfate and 17beta-estradiol-3-sulfate. This system gives high resolution of the estrogen conjugates in small eluent volumes in less than 30 min. The advantages of this high pressure liquid chromatographic system over other methods of separation are discussed.

Testosterone metabolites in dog bile

Testosterone-1,2-3H was injected intravenously into a male dog with a bile fistula and bile and urine collected. The radioactivity was excreted preponderantly in bile (52% of the injected dose) in 6 hours; only 12% appeared in the urine. Methods to study the biliary metabolites of testosterone in this and other animals were developed. Satisfactory conjugate patterns were obtained by fractionation on DEAE-Sephadex A-25 columns using two different elution systems. In addition to an unchanged fraction, six different monoglucuronide fractions were separated. No other conjugates were isolated. Lipidex 5000 column chromatography, TLC and paper chromatography were used for the isolation and purification of aglycone metabolites, which were further identified by co-crystallization methods. The biliary metabolites of testosterone were epiandrosterone (3beta-hydroxy-5alpha-androstan-17-one), etiocholanlone (3alpha-hydroxy-5beta-androstan-17-one), 5alpha-androstan-3beta, 17beta-diol, 5beta-androstan-3alpha, 17beta-diol and 5beta-androstan-3beta,17beta-diol.

The metabolism of estrone and estradiol-17beta and their 3-sulfates by female guinea pig liver microsomes

The metabolism, by female guinea pig liver microsomes of estrogen 3-sulfates (estrone-3-sulfate and 17beta-estradiol-3-sulfate) was compared to that of the unconjugated estrogens, estrone and estradiol-17beta. Metabolites identified indicated that 16beta-hydroxylated products (16beta judrpxuestrpme amd 16 epiestriol) arose mainly from the free estrogens while 16alpha-hydroxy steroid sulfates (16alpha hydroxyestrone-3-sulfate and estriol-3-sulfates and estriol-3-sulfate) were predominantly formed from the sulfated estrogens. These results show that the sulfate moiety at position 3 of the steroids directs 16-hydroxylation from the beta to the alpha configuration.

Estrogen metabolism in nonhuman primates. I. In vitro biosynthesis of estrogen glucosiduronates in rhesus monkey liver

Estrone glucosiduronate, 17beta-estradiol-3-glucosiduronate, 17beta-estradiol-17-glucosiduronate and estriol-16alpha-glucosiduronate have been biosynthesized in substantial yield by incubation of radioactive estrone, 17beta-estradiol, estriol and uridine diphosphoglucosiduronic acid with rhesus monkey liver homogenates. The metabolites were characterized by chromatography on Celite and DEAE-Sephadex, enzyme hydrolysis, derivative formation and crystallization to constant specific activity. The percent conversion to 17beta-estradiol-17-glucosiduronate from 17beta-estradiol ranged between 56-71%; from estrone, the conversion was 49-54%. Other metabolites formed from estradiol were estrone glucosiduronate (12-21%) and 17beta-estradiol-3-glucosiduronate(5-12%). The same metabolites derived from estrone accounted for 18-28% and 10-14% respectively. After estriol incubation, more than 90% of the steroid was converted to estriol-16alpha-glucosiduronate with no detectable estriol-3-glucosiduronate. This report represents the first time that 17beta-estradiol-17-glucosiduronate has been reported as a metabolite in the rhesus monkey and this is the only known species which forms 17beta-estradiol-17-glucosiduronate as the predominant metabolite of either estrone or estradiol in vitro. Rhesus monkey liver is similar to the human and baboon in that it metabolizes estriol exclusively to estriol-16-glucosiduronate.

Metabolites of estradiol-17beta in guinea pig uterus late in pregnancy

The metabolism of estradiol-17beta by the guinea pig uterus late in pregnancy was studied in vivo and in vitro. Whole uteri were examined for estrogen metabolites one hour following an intravenous injection of [3H]-estradiol-17beta or uterine sections were examined after incubation for one hour at 37 degrees C in medium containing [3H]-estradiol-17beta. In both instances uterine tissue metabolized estradiol-17beta to five products; estrone, estrone-3-sulfate, 17beta-estradiol-3-sulfate, estrone-3-glucuronide and 17beta-estradiol-3-glucuronide. Of the total radioactive products 11-43% were glucuronides, 17-26% were sulfates and 4-17% was estrone. These results indicate that the guinea pig uterus actively transforms estradiol-17beta into glucuronides and sulfates late in pregnancy.

Isolation, determination of structure and synthesis of the acid-labile conjugate of aldosterone

1. After administration of 600mg of 3H-labelled aldosterone to human volunteers, 57 mg of homogeneous acid-labile conjugate was isolated from the urine and identified as aldosterone 18 beta-D-glucosiduronic acid. 2. Esterification and acetylation of the conjugate gave a tetra-acetate methyl ester, which, by measurement of the optical rotation and nuclear-magnetic-resonance spectrum, was shown to be a beta-glucosiduronate. This tetra-acetate methyl ester was synthesized in approx. 10% yield by the Koenigs-Knorr procedure. 3. Removal of the acetyl and methyl ester groups from the tetra-acetate methyl ester with alkali was accompanied by almost complete isomerization at C-17 to give 17-isoaldosterone 18 beta-D-glucosiduronic acid. 4. To prevent inversion at C-17 during removal of the acetate and ester groups of beta-glucosiduronate (a) the 3,20-disemicarbazone was prepared, (b) the acetate and ester groups were removed from the disemicarbazone by treatment with alkali, and (c) the semicarbazone groups were removed from the product at pH 2.0, and aldosterone 18 beta-D-glucosiduronic acid was obtained in 47% overall yield. 5. In the presence of components used to synthesize beta-glucosiduronate by the Koenigs-Knorr reaction this substance is converted slowly into the alpha-glucosiduronate; this conversion is responsible, in part, for the low yield of beta-glucosiduronate. 6. Two additional conjugates were obtained in the Koenigs-Knorr reaction; a provisional structure was assigned to one substrate. The other substance is a C-18 alpha-glucosiduronate. Removal of the acetyl and ester groups from C-18 alpha-glucosiduronate gave the alpha-glucosiduronic acid in 84% yield and the 17-isoaldosterone alpha-glucosiduronic acid in 12% yield. 7. The rate at which several types of beta-glucuronidase hydrolyse the foregoing steroidal alpha- and beta-glucosiduronic acids is given.

Water-soluble metabolites of the estrogens. Quantitation of C-18 tetrols in rat feces

Several radioactive estrogens possessing one, two and three hydroxyl groups were injected orally (and in the case of estrone sulfate also intraperitoneally) into adult male rats. The rats were either intact or had ligated or cannulated bile ducts. Two unconjugated estrogen tetrols together represented 21 - 87% of the total metabolites in the intact rat. One of the tetrols was 2-hydroxyestriol (estra-1,3,5(10)-triene-2,3,16alpha,17beta-tetrol); the other may be estra-1,3,5(10)-triene-2,3,6xi,17beta-tetrol but this was not confirmed. It is concluded that poly-hydroxylated estrogens represent a very large proportion of the previously unidentified water-soluble metabolites of the estrogens in the adult male rat.

Identifications of radioactive steroid estrogen conjugates in blood plasma of laying hens after intramuscular injection of (4--14C)-estrone

[4--14C] Estrone was injected intramuscularly into six laying hens. Fifty minutes later the hens were exsanguinated. The plasmas were examined for conjugates of radioactive phenolic steroids by recovery on columns of Amberlite XAD-2 or by extraction with tetrahydrofuran followed by chromatography on a column of DEAE-Sephadex A-25 in a gradient of NaCl. The biggest Sephadex chromatographic fraction (50,4% of total) contained about 42% of its radioactivity as estradiol-17alpha-3-sulfate and 18% as estradiol-17beta-3-sulfate and the remaining 40% was identified tentatively as estradiol-17alpha-17-sulfate plus a small proportion of estradiol-17beta-17-sulfate. The second biggest Sephadex chromatographic fraction (12.7% of total) was a mixture of conjugates not further identified. Minor fractions identified comprised estrone-beta-glucuronide (2.8%), estradiol-17alpha-3-beta-glucuronide (2.8%), estradiol-17beta-3-beta-glucuronide (2.3%) and estrone sulfate (6.0%). Evidence was obtained for the presence of small proportions of estradiol-17alpha disulfate and estradiol-17beta disulfate.

Aflatoxin P-1: a new aflatoxin metabolite in monkeys

A new phenolic derivative of aflatoxin B(1), appearing mainly in conjugated form, was identified as the principal urinary metabolite of aflatoxin B(1) in rhesus monkeys. Its identification in human urine might facilitate estimation of aflatoxin exposure in human populations.

Metabolism of arterial plasma estrogens by the splanchnic organs of the dog in vivo

In order to study the splanchnic metabolism of blood-borne estrogens, a constant infusion of estrone-6,7-(3)H was made in a series of dogs, and arteriovenous (A-V) differences at equilibrium were determined for estrone-6,7-(3)H and for its products estradiol-17beta, estrone sulfate, estrone glucosiduronate, and estradiol-17beta glucosiduronate across the splanchnic bed (artery-hepatic vein), the small intestine (artery-superior mesenteric vein), and the spleen (artery-splenic vein). Per cent extractions (100 - [V/A] 100) were calculated. The plasma metabolic clearance rate (MCR) for estrone was measured. Principal findings were as follows: mean MCR was 731 liters/day per m(2), SEM 50. By comparison with estimated hepatic plasma flow and using the observed splanchnic extraction of estrone, 45-71% of estrone metabolism was calculated to be extrasplanchnic. The significant mean per cent extractions were as follows (SEM in parentheses): splanchnic bedestrone 85.9 (1.92), estradiol-17beta 88.11 (3.36), estrone sulfate 27.9 (5.22), estrone glucosiduronate -48.5 (9.33), estradiol-17beta glucosiduronate -33.3 (80.3); small intestine-estrone 45.3 (2.60), estradiol-17beta 46.1 (12.9), estrone glucosiduronate - 30.8 (7.9); spleen-estrone 35 (3.8), estrone glucosiduronate 12 (3.7). These results lead to the following conclusions. Both estrone and estradiol-17beta are nearly completely extracted in one passage through the splanchnic bed. There is net uptake of estrone sulfate and net production of estrone glucosiduronate and of estradiol-17beta glucosiduronate by the splanchnic bed. There is net uptake of estrone and of estradiol-17beta by the intestine, associated with substantial net production of estrone glucosiduronate. There is net uptake of estrone by the spleen and a small but significant net uptake of estrone glucosiduronate.