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Query: EC:3.1.6.1 (
sulfatase
)
3,205
document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)
To study the effects of dehydroepiandrosterone sulfate (DHA-S) on placental steroid metabolism and maternal steroidal profiles at term, the following in vivo and in vitro experiments were performed. Two hundred mg of DHA-S was given to five pregnant women 30 minutes prior to delivery. After delivery, the placenta was collected and
3 beta-hydroxysteroid dehydrogenase
(3 beta-HSD) and
sulfatase
activity was determined by measuring the rate of conversion of pregnenolone to progesterone and DHA-S to DHA. The amount of C21-delta 4-steroid in the placental tissue was measured by gas chromatography mass spectrometry (GC-MS) and compared with the control groups. The maternal serum concentration of several steroids was also measured by GC-MS before and after the administration of DHA-S. 3 beta-HSD activity in the placentae from the mothers who received DHA-S before delivery was significantly lower than in the controls. On the other hand, no significant change was observed in the activity of
sulfatase
. The serum concentration of progesterone (P) and 20 alpha-dihydro-P (20-P) before DHA-S loading decreased following the administration whereas estradiol (E), DHA, and androstenedione (A) levels increased. To study the direct effect of DHA-S and its related steroids on placental 3 beta-HSD activity, placental tissue samples were incubated with pregnenolone in vitro. Several other steroids were added simultaneously into the medium. It was observed that placental 3 beta-HSD activity was directly inhibited by DHA-S. These results indicate that DHA-S inhibits 3 beta-HSD activity in the placenta and subsequently causes a reduction in P and 20-P.
...
PMID:Effects of DHA-S on placental 3 beta-hydroxysteroid dehydrogenase activity, progesterone and 20 alpha-dihydroprogesterone concentrations in placenta and serum. 214 69
To study the function of the placenta from the viewpoint of placental aging, we measured the activity of various enzymes,
sulfatase
,
3 beta-hydroxysteroid dehydrogenase
+ isomerase (3 beta-HSD) and aromatizing enzyme, which are involved in the synthesis of estrogen in the placenta, as well as placental RNA and DNA levels during gestation. Our results are as follow; Enzymes involved in estrogen synthesis in human placental villi. Sulfatase activity (n mole/flask/10 min) in each trimester was not significantly different (4.10 +/- 0.10 in the first, 3.40 +/- 0.49 in the second and 4.33 +/- 0.67 in the third). 3 beta-HSD activity (n mole/flask/10 min) in each trimester was not significantly different (2.57 +/- 0.55 in the first, 2.70 +/- 0.30 in the second and 2.90 +/- 0.53 in the third). Aromatizing enzyme activity (n mole/flask/30 min) in cytosome fraction in each trimester was not significantly different (1.80 +/- 0.28 in the first, 1.60 +/- 0.28 in the second and 2.40 +/- 0.28 in the third). However, in the total homogenate, it was significantly higher in the third trimester (6.27 +/- 0.25) than in the first (3.83 +/- 0.85) or second (3.40 +/- 0.14). RNA and DNA concentrations in human placental villi. The RNA concentration (mg/g tissue) in each trimester was insignificantly different (2.48 +/- 0.20 in the first, 2.57 +/- 0.58 in the second and 2.63 +/- 0.42 in the third). However, the DNA concentration was significantly higher in the second (2.49 +/- 0.34) and third (2.42 +/- 0.45) trimesters than in the first (1.62 +/- 0.32).(ABSTRACT TRUNCATED AT 250 WORDS)
...
PMID:Growth and function of the placenta--with special reference to various enzymes involved in the biosynthesis of steroids in the human placenta. 242 4
Collagenase-dispersed cells from human chorion laeve were examined on Percoll gradients. The
3 beta-hydroxysteroid dehydrogenase
(a trophoblast marker) and steroid sulfatase activities of the cells were measured and a system was developed to isolate enriched preparations of the trophoblast cells. No cells were found to sediment at Percoll concentrations greater than 50%, and using continuous gradients of Percoll there appeared to be cells with different
3 beta-hydroxysteroid dehydrogenase
(3 beta HSD): steroid sulfatase ratios sedimenting in different regions of the gradient. Cells with a high ratio were found in the denser region of the gradient. Continuous gradients provided inadequate separations of distinct populations of cells, thus to obtain a more reproducible system to isolate cells, discontinuous gradients of Percoll were studied. A discontinuous gradient composed of 5, 20, 40, and 60% Percoll was developed and three bands of cells were found sedimenting at the 20, 40 and 60% interfaces, respectively. The number and appearance of cells at the 20 and 60% interfaces varied from tissue to tissue. In contrast, the cells sedimenting at the 40% interface were less variable, a substantial number was found to be present in every tissue studied, they were similar in appearance to the trophoblast cells and had high 3 beta HSD:
sulfatase
ratios.
...
PMID:Steroid metabolism by cells from human chorion laeve isolated on Percoll gradients. 300 69
The purpose of this study was to develop primary cultures of human chorion laeve cells and examine certain aspects of steroid metabolism during culture. Tissues obtained by elective cesarean section at term (38-40 weeks) were dispersed with collagenase. Cells were isolated on Percoll gradients at the interface between 20% and 40% Percoll and examined in primary culture for up to 1 week. Cultures were carried out in chemically defined media supplemented with 10% or 0.1% fetal calf serum (FCS). The morphological and biochemical properties of the cells were different in the two systems. In 0.1% FCS, cells formed clumps of tissue within 16 h of plating, and there was no cell replication. In contrast, in 10% FCS, the cells formed a carpet of tissue and reached confluence after 5 days in culture, resulting in increased DNA and protein content and thymidine incorporation in the dishes. Three steroidogenic enzymes were studied during culture: alkyl steroid sulfatase,
estrogen sulfatase
and
3 beta-hydroxysteroid dehydrogenase
. The sulfatases had higher activities in 0.1% than in 10% FCS, and their activities decreased markedly during the culture period. In contrast,
3 beta-hydroxysteroid dehydrogenase
activity was higher in 10% FCS than in 0.1% FCS. Activity remained constant during the culture period in 0.1% FCS and increased in 10% FCS. In the latter system this increase resulted in the enzyme maintaining a constant specific activity during culture. These studies describe two viable systems of chorion laeve cells in primary culture, which may be valuable for studying long term and/or subtle effects on various metabolic aspects of this tissue.
...
PMID:Primary culture of cells from human chorion laeve: steroid metabolism and properties of cells grown in defined media supplemented with 0.1% or 10% fetal calf serum. 345 98
Serum 3 beta-hydroxy-5-cholenoic acid (3 beta-OH-delta 5) was analyzed in 100 cases (90 patients with hepatobiliary diseases, 10 normal subjects) and its clinical significance investigated. The measurement of 3 beta-OH-delta 5 was performed by high performance liquid chromatography (HPLC) with immobilized
3 beta-hydroxysteroid dehydrogenase
(3 beta-HSD) as the enzyme column. Esterified 3 beta-OH-delta 5 was measured after enzymatic hydrolysis with
sulfatase
and beta-glucuronidase. 3 beta-OH-delta 5 was hardly detected in normal cases. On the other hand, serum 3 beta-OH-delta 5 levels were remarkably high in cholestatic cases and also high in other cases with high bilirubin levels. The ratio of glycine- to taurine-conjugates (G/T ratio) was effective in discriminating cholestasis from hepatocellular damage such as in cases of acute hepatitis or fulminant hepatitis. More than 90% of the 3 beta-OH-delta 5, which is toxic, was sulfated or glucuronidated, suggesting detoxification by esterified bile acids. Significant increases of taurine-conjugated 3 beta-OH-delta 5 were observed in cases with pruritus, and a relationship between taurine-conjugated and pruritus was presumed. Therefore, analysis of 3 beta-OH-delta 5 is considered to be effective in clarifying the pathogenesis of hepatobiliary diseases.
...
PMID:Clinical evaluation of serum 3 beta-hydroxy-5-cholenoic acid in hepatobiliary diseases. 347 20
We examined whether different cell subpopulations from human fetal membranes and decidua produce steroids (estrone and progesterone) and metabolize prostaglandins (prostaglandin F2 alpha to 13, 14-dihydro-15-keto-prostaglandin F2 alpha and if these changed with labor. Amnion, chorion, and decidua were obtained at elective cesarean section at term or at spontaneous labor. Cells were dispersed with collagenase and separated by density on discontinuous Percoll gradients. At cesarean section there was a major broad band of cells from amnion and chorion. This band contained most of the estrone sulfatase (estrone sulfate to estrone) activity. The
3 beta-hydroxysteroid dehydrogenase
(pregnenolone to progesterone conversion) and prostaglandin F2 alpha metabolizing activities were present in these cells and those that migrated at greater Percoll densities. Amnion and chorion obtained after spontaneous labor had two major bands of cells. Estrone
sulfatase
was present in cells from both hands, whereas progesterone output from pregnenolone and prostaglandin F2 alpha metabolism predominated in the second band of cells with greater density. This pattern was particularly apparent in chorion. Dispersed cells from decidua tended to migrate throughout the gradient. In general, estrone sulfate to estrone conversion predominated in lighter cells whereas progesterone output from pregnenolone and prostaglandin F2 alpha metabolism predominated in cells of greater density. The output of progesterone from pregnenolone was significantly lower in cell preparations from chorion and decidua at spontaneous labor compared with cesarean section. We conclude that human amnion, chorion, and decidua contain distinct cell subpopulations based on Percoll migration and that in the membranes these change between cesarean section and spontaneous labor. Partial separation of estrone sulfatase from
3 beta-hydroxysteroid dehydrogenase
and prostaglandin F2 alpha metabolizing activities has been demonstrated, which raises the possibility of paracrine interactions in vivo.
...
PMID:Steroid synthetic and prostaglandin metabolizing activity is present in different cell populations from human fetal membranes and decidua. 348 Jun 92
Certain steroid metabolic properties of chorion laeve from dichorionic twin pregnancies were examined to determine whether they were present in chorion not contaminated by decidua or serum. In the chorion situated between the two amniotic sacs and not in contact with decidua, aryl
sulfatase
,
3 beta-hydroxysteroid dehydrogenase
, and aromatase activities were found. This indicates that these reactions are present in chorion laeve and were not previously ascribed to this tissue because of decidual contamination. Specific cortisol binding was also present in this area of chorion laeve, which excludes serum contamination. It is suggested that the specific steroid-binding protein in the membranes may be derived from the transcortin-like protein present in amniotic fluid.
...
PMID:Steroid metabolism by human chorion laeve from dichorionic twin pregnancies. 385 88
It is well recognized that in the fetal adrenal cortex,
3 beta-hydroxysteroid dehydrogenase
(3 beta-HSD) activity is lower and in fetal tissues, steroid sulfokinase (SK) is higher than in the adult. In order to clarify a part of the development processes of the adrenal cortex or steroidgenesis in humans, a combined radioimmunoassay (RIA) method to estimate serum 17 alpha-hydroxypregnenolone (17-OH-delta 5 P), 17 alpha-hydroxypregnenolone sulfate (17-OH-delta 5 P-S) and 17 alpha-hydroxyprogesterone (17-OH-delta 4P) was devised. The method consisted of the following procedures: 1) diethyl ether extraction and chromatographic separation of unconjugated steroids (17-OH-delta 5P and 17-OH-delta 4P), 2) enzymatic hydrolysis of 17-OH-delta 5P-S using the residue of diethyl ether extraction for a material, 3) diethyl ether extraction and chromatographic purification of hydrolyzed 17-OH-delta 5P-S, and 4) RIAs for 17-OH-delta 5-P to estimate 17-OH-delta 5P and 17-OH-delta 5P-S concentration, and for 17-OH-delta 4P. Extracted 17-OH-delta 5P was well separated from 17-OH-delta 4P by Sephadex LH-20 microcolumn chromatography, using a benzene/methanol = 95/5 (v/v) solvent as a mobile phase. Several procedures for hydrolysis or solvolysis of 17-OH-delta 5P-S were compared using available tritiated delta 5-3 beta-hydroxysteroids including dehydroepiandrosterone (DHA), DHA sulfate (DHA-S) and 17-OH-delta 5P, and it was found that the most suitable method was an enzymatic hydrolysis by
arylsulfatase
from Helix Pomatia in an appropriate condition in which the percent hydrolysis was 92.9 +/- 1.2 (mean +/- SEM)%. The final percent recoveries were 88.7 +/- 1.2% in 17-OH-delta 4P, 90.7 +/- 1.4% in 17-OH-delta 5P and 78.1 +/- 2.1% in 17-OH-delta 5P-S, respectively. A suitable antiserum and its final dilution titer for RIA of 17-OH-delta 5P (hydrolyzed 17-OH-delta 5P-S also) was 1:12,000 dilution of anti-17-OH-delta 5P-3-succinate-BSA serum. An anti-7-oxo-17-OH-delta 5P-7-carboxymethyloxime-BSA serum was considered to be unsuitable for the measurement of hydrolyzed 17-OH-delta 5-P-S, presumably because of a significant cross-reactivity with a large amount of unknown steroid sulfates simultaneously hydrolyzed.(ABSTRACT TRUNCATED AT 400 WORDS)
...
PMID:[A combined radioimmunoassay method for the determination of 17 alpha-hydroxypregnenolone, 17 alpha-hydroxypregnenolone sulfate and 17 alpha-hydroxyprogesterone in human blood]. 405 6
Using microsomes isolated from term human placentae kinetic analyses of each of the enzymes involved in estrogen synthesis from dehydroepiandrosterone sulfate have been carried out and the following parameters were found:
sulfatase
, Michaelis-Menten constant (Km) = 16,000 +/- 5,000 nM, maximum velocity (Vm) = 2.0 +/- 0.5 nmol X min-1 X mg protein-1;
3 beta-hydroxysteroid dehydrogenase
(3 beta-HSD), Km = 15 +/- 3 nM, Vm = 1.8 +/- 0.4 nmol X min-1 X mg protein-1; aromatase, Km = 14 +/- 4 nM, Vm = 0.12 +/- 0.02 nmol X min-1 X mg protein-1. From these values one can predict that, theoretically, the rate-limiting enzyme in estrogen synthesis from dehydroepiandrosterone sulfate (DS) should change from the
sulfatase
at low concentrations of substrate to the aromatase at higher concentrations. In order to test this hypothesis we developed a system which allowed the formation of estrogens from DS, dehydroepiandrosterone, and androstenedione to be measured and the appropriate intermediates to be isolated. The
sulfatase
was found to be rate limiting at concentrations of DS below 2 microM and the aromatase was found to be rate limiting at higher concentrations. These data may explain why previous perfusion studies of human placentae indicated the
sulfatase
was the rate-limiting enzyme in estrogen synthesis yet in vitro studies found that it was the aromatase. Steroids previously shown to inhibit the 3 beta-HSD were examined for their ability to inhibit the formation of estrogens from DS. Although 3 beta-HSD activity was markedly inhibited this had little effect on the overall conversion of DS to estrogens, until high concentrations of inhibitors were used. The data also underline the importance of studying enzyme systems rather than single enzymes when studying steroid synthesis.
...
PMID:Kinetic studies on the formation of estrogens from dehydroepiandrosterone sulfate by human placental microsomes. 623 32
The importance of the placental 3 beta-steroid sulfatase for placental biosynthesis of estrogens is demonstrated by a case report of a placental
sulfatase
deficiency. The absolute deficiency of this enzyme in our case is demonstrated in vivo by the intravenous dehydroepiandrosterone sulfate loading test and in vitro by placental enzyme tests. Steroid concentrations in serum after injection of dehydroepiandrosterone sulfate (DHEA-S) are compared with those in a group of pregnant women without placental enzyme defects and in a group of nonpregnant women. Placental in vitro tests demonstrate the intact
3 beta-hydroxysteroid dehydrogenase
-delta 4,5 isomerase-aromatase-system in the placenta with
sulfatase
deficiency. The lack of placental hydrolysis results in low concentrations of estrone and estradiol-17 beta in the maternal serum, which are only 5.9% and 12.5%, respectively, of the mean values of the control group. This indicates that more than 90% of estrone and more than 85% of estradiol-17 beta measured in the maternal serum are from DHEA-S as precursor. The remaining concentrations are converted mainly from dehydroepiandrosterone (DHEA), which needs no hydrolysis. Maternal serum concentrations of estriol are under the detection limit of the radioimmunoassay. This is due to the absence of the so called "neutral pathway" and the "phenolic pathway" with 16 alpha-hydroxydehydroepiandrosterone sulfate (16 alpha-OH-DHEA-S) and DHEA-S respectively as precursors. The insignificance of the "placental pathway" for the total biosynthesis of estriol is demonstrated. The placental
sulfatase
seems to have no great importance for the biosynthesis of the C21-steroids.
...
PMID:Placental steroid metabolism in a case of placental sulfatase deficiency. 644 78
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