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1.
Specific 21-deoxycortisol (21-DF) antiserum was raised in New Zealand white rabbits using a 21-DF-3,20-oxime-bovine serum albumin complex. Plasma radioimmunoassay of 21-DF was developed and used together with a radioimmunoassay of 17-hydroxyprogesterone (17-OH-P) for diagnosis of patients with 21-hydroxylase deficiency of congenital and postpubertal forms. The assays were performed in plasma extracts after isolation by paper chromatography. The response of plasma 21-DF and 17-OH-P to i.v. ACTH (25 IU) was studied in 15 adult controls and compared to 8 women with the late onset form of 21-hydroxylase deficiency and 23 women with idiopathic hirsutism. Normal 21-DF values for women were 6.9 +/- 3.6 ng/dl and for men 9.71 +/- 2.73 ng/dl. Newborn children (age: 3-10 days) had a value of 8.3 +/- 4.8 ng/dl. These values are definitely lower than the lowest value ever published. This is possibly due to the specificity of the antibody. During the menstrual cycle the 21-DF values did not change. The baseline and post-stimulated concentrations of hormone were similar in controls and women with hirsutism but were significantly higher in women with the late onset form of 21-hydroxylase deficiency. In the congenital form of 21-hydroxylase deficiency the 21-DF values (baseline) were high. In general, the 21-DF and 17-OH-P values have shown parallel changes. However, one case of 21-hydroxylase deficiency with elevated 21-DF but normal 17-OH-P was observed. The use of 21-DF for the diagnosis of 21-hydroxylase deficiency is suggested.  相似文献   

2.
The concentration of 17-OH-progesterone was determined in second trimester amniotic fluid collected from 58 pregnancies at risk for fetal 21-hydroxylase deficiency. The prediction was incorrect in 1 male nonsalt-loser who had an increased plasma 17-OH-progesterone concentration at 3 months of age. All 11 infants predicted to be affected were salt-losers. The adrenals from 2 affected fetuses available for study were significantly enlarged in comparison with adrenal size in 84 normal fetuses from 15 to 26 weeks' gestation. Amniotic fluid steroid analysis reliably predicts the fetus with 21-hydroxylase deficiency most at risk in early infancy. There is no evidence from this study to indicate that ACTH is not the main trophic factor for fetal adrenal growth and steroidogenesis.  相似文献   

3.
The ACTH test is important when hirsutism occurs in women with a slight 21-hydroxylase deficiency, and normal basal 17-OH Progesterone (17-OH-P/plasma levels). Extensive hormonal assays: LH, FSH, Prolactin, 17 beta-estradiol (E2), Estrone, 17OH-P, Androstenedione, Testosterone, Cortisol (C), Dehydroepiandrosterone-S (DEA-S) were carried out in 36 hirsute women. 13 of these presented hormone levels as found in polycystic ovary syndrome (PCOS), 6 women presented a slight 21-hydroxylase deficiency (increased plasma 17-OH-P and decreased C after ACTH test with significant, p less than 0.01, increase of 17-OH-P/C and 17 women presented idiopathic hirsutism (IH). The hormonal pattern, in the basal condition, is not different in IH or in slight 21-hydroxylase deficiency. The ACTH test is able to differentiate between IH and adrenal hirsutism.  相似文献   

4.
17-hydroxyprogesterone (17-OH-P) was measured in various populations by radioimmunoassay, using a highly specific antibody produce in the rabbit. Dynamic tests were performed with ACTH, dexamethasone and estroprogestative drugs and the role played by the adrenals and the ovaries in 17-OH-P production could be assessed. 17-OH-P determination is of interest in that, it allows the diagnosis of 21-hydroxylase deficiency, where values above 10 ng/ml are often found. Associated with the measure of testosterone and delta 4-androstenedione, it is also useful in the management of the disease. In the mild form of congenital adrenal hyperplasia with late revelation of the symptoms, determination of 17-OH-P following ACTH stimulation allows of relative diagnosis.  相似文献   

5.
Serum concentrations of 17-hydroxypregnenolone, 17-hydroxypregnenolone sulfate and 17-hydroxyprogesterone were measured simultaneously in patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency, using a combined radioimmunoassay method. All these precursor steroids were found to be markedly elevated in the sera of untreated patients with a salt-losing form of the disease, whereas, in untreated patients with a simple virilizing form, only the concentration of unconjugated steroids was increased and the 17-hydroxypregnenolone sulfate concentration remained within the normal range. Among the patients with a salt-losing form under maintenance therapy, these steroids were all still significantly increased in those on insufficient control, whereas only 17-hydroxyprogesterone was significantly but slightly increased in those on adequate control. Although the mechanism whereby the serum 17-hydroxypregnenolone sulfate concentration is not increased in the untreated simple virilizers is unknown, both a milder degree of 21-hydroxylase deficiency and a role of 17-hydroxypregnenolone sulfate in adrenal steroid production as a kind of supplier are suggested as possible explanations, especially in the neonatal period and early infancy. Thus, this study showed the serum concentrations of 17-hydroxypregnenolone and its sulfate together with 17-hydroxyprogesterone in patients with 21-hydroxylase deficiency in various conditions.  相似文献   

6.
Basic and clinical aspects of congenital adrenal hyperplasia   总被引:1,自引:0,他引:1  
Defective steroid 21-hydroxylation is the most common of the biochemical defects causing hyperplasia of the adrenal cortex. The genetic mode of transmission of all enzyme abnormalities seen in cortisol biosynthesis is autosomal recessive. Steroid 21-hydroxylase deficiency has three currently accepted forms: the simple virilizing and salt-wasting variants of the classical deficiency, and the nonclassical (attenuated) form, which shows a wide clinical range of effects and whose characterization emerged from co-ordinated hormonal testing and family studies. More recent molecular genetic studies have started to identify specific mutations altering 21-hydroxylase activity. Defects in the other enzymes occur more rarely and are less well known, although initial work with abnormal 11 beta-hydroxylase and 3 beta-hydroxylase indicates that allelic gene defects may be correlated with different clinical phenotypes seen for these disorders also. The gene for the enzyme steroid 21-hydroxylase, a cytochrome P-450, is situated within the major histocompatibility complex on the p arm of human chromosome 6, proximal to the HLA-B antigen locus. Linkage disequilibria between certain B and DR alleles and classical and nonclassical 21-hydroxylase deficiency permit the use of HLA genotyping in conjunction with hormonal evaluation for diagnosis of this disorder and for identification of carrier haplotypes in population studies. Test programs have shown the feasibility of neonatal screening for 21-hydroxylase deficiency by blood-spot hormonal assay for elevated 17-hydroxyprogesterone. Prenatal detection of disease currently depends on HLA serotyping of cultured aminocytes jointly with measurement of amniotic 17-hydroxyprogesterone (13-18 week gestation); molecular genetic techniques with more specific nuclear probes will improve the specificity of this test and will in addition permit even earlier definitive fetal genotyping by chorionic villus biopsy (6-10 week gestation).  相似文献   

7.
Summary The possible genetic linkage between HLA and neuraminidase deficiency was studied in a female patient with combined abnormalities of the infantile form of sialidosis type II and congenital adrenal hyperplasia caused by 21-hydroxylase deficiency, and six members of her family. Her parents were consanguineous. The patient has the homozygous HLA haplotypes, TS-1, Cw3, DRw9. Four of the tested family members, including a distant male relative with congenital adrenal hyperplasia, were heterozygous of this HLA complex, and the neuraminidase activities in their skin fibroblasts and/or lymphocytes showed values between those of the patient and controls (25–48%), suggesting a carrier state of sialidosis. This indicates that the neuraminidase deficiency gene, similar to the 21-hydroxylase deficiency gene, is closely linked to the HLA genotype and is located on chromosome 6.  相似文献   

8.
The feasibility and accuracy of gene-specific molecular genetic diagnosis for congenital adrenal hyperplasia due to 21-hydroxylase deficiency was studied in a group of 24 pregnancies at 25% risk of carrying an affected fetus. Chorionic villus sampling was performed at 9–10 weeks' gestation. Southern analysis and polymerase chain reaction, followed by allele-specific hybridization for a panel of nine known mutations, were performed for each family. Mutations were identified in 95% of chromosomes examined; the molecular diagnosis was accurate in 96% of infants as confirmed by postnatal examination. The most common mutation identified was an A-to-G transition at base 656 in the second intron, the result of an apparent gene conversion. In one family, there had been a de novo mutation in intron 2, which was detected in the proband, but not in the mother or in the fetus. We conclude that first trimester prenatal diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency is feasible and accurate employing CYP21-specific probes.  相似文献   

9.
Congenital adrenal hyperplasia: update on prenatal diagnosis and treatment   总被引:1,自引:0,他引:1  
The diagnostic term congenital adrenal hyperplasia (CAH) applies to a family of inherited disorders of steroidogenesis caused by an abnormality in one of the five enzymatic steps necessary in the conversion of cholesterol to cortisol. The enzyme defects are translated as autosomal recessive traits, with the enzyme deficient in more than 90% of CAH cases being 21-hydroxylase. In the classical forms of CAH (simple virilizing and salt wasting), owing to 21-hydroxylase deficiency (21-OHD), androgen excess causes external genital ambiguity in newborn females and progressive postnatal virilization in males and females. Non-classical 21-OHD (NC21OHD) refers to the condition in which partial deficiencies of 21-hydroxylation produce less extreme hyperandrogenemia and milder symptoms. Females do not demonstrate genital ambiguity at birth.

The gene for adrenal 21-hydroxylase, CYP21, is located on chromosome 6p in the area of HLA genes. Specific mutations may be correlated with a given degree of enzymatic compromise and the clinical form of 21-OHD. NC21OHD patients are predicted to have mild mutations on both alleles or one severe and one mild mutation of the 21-OH locus (compound heterozygote). In most cases the mutation groups represent one diagnosis (e.g., Del/Del with SW CAH), however we have found several non-correlations of genotype to phenotype. Non-classical and classical patients were found within the same mutation group. Phenotypic variability within each mutation group has important implications for prenatal diagnosis and treatment.

Prenatal treatment of 21-OHD with dexamethasone has been utilized for a decade. An algorithm has been developed for prenatal diagnosis and treatment, which, when followed closely, has been safe for both the mother and the fetus, and has been effective in preventing ambiguous genitalia in the affected female newborn. This is an instance of an inborn metabolic error successfully treated prenatally.

Since 1986, prenatal diagnosis and treatment of congenital adrenal hyperplasia due to 21-hydroxylase deficiency (21-OHD) has been carried out in 403 pregnancies in The New York Hospital–Cornell Medical Center. In 280, diagnoses were made by amniocentesis, while 123 were diagnosed using chorionic villus sampling. Of the 403 pregnancies evaluated, 84 babies were affected with classical 21-OHD. Of these, 52 were females, 36 of whom were treated prenatally with dexamethasone. Dexamethasone administered at or before 10 weeks of gestation (23 affected female fetuses) was effective in reducing virilization. Thirteen cases had affected female sibs (Prader stages 1–4); 6 of these fetuses were born with entirely normal female genitalia, while 6 were significantly less virilized (Prader stages 1–2) than their sibs, and one was Prader stage 3. Eight newborns had male sibs; 4 were born with normal genitalia, 3 were Prader stages 1–2, and 3 were born Prader stages 3–4. No significant or enduring side effects were noted in either the mothers or the fetuses, indicating that dexamethasone treatment is safe. Prenatally treated newborns did not differ in weight, length, or head circumference from untreated, unaffected newborns.

Based on our experience, proper prenatal diagnosis and treatment of 21-OHD is effective in significantly reducing or eliminating virilization in the newborn female. This spares the affected female the consequences of genital ambiguity of genital surgery, sex misassignment, and gender confusion.  相似文献   


10.
A comparative study of adrenal morphology between normal fetuses and those with anencephaly or congenital adrenal hyperplasia (CAH) was performed in order to examine the hypothesis that fetal adrenal mass and structure are adrenocorticotrophin (ACTH)-dependent throughout gestation. Combined adrenal weight in 102 normal fetuses was used to establish a reference range for the gestational ages of 15-27 weeks. During this period, mean adrenal weight showed a 6-fold linear increase. In 38 anencephalic fetuses of similar gestation age, adrenal weight was below the normal range and did not show a rise. Three fetuses with CAH (18, 22 and 30 weeks gestation) had adrenal weights considerably above the normal range. Adrenal cortical thickness was significantly increased in CAH fetuses, largely as a consequence of cell hypertrophy, whereas decreased cortical thickness in the anencephalic group represented cellular hypoplasia. Conspicuous secretory granules in the cytoplasm was the electron-micrographic feature of the adrenal gland in the 22-week fetus with CAH. These observations are consistent with close dependency of fetal adrenal growth and development upon fetal pituitary function from an early age, mediated primarily through ACTH.  相似文献   

11.
OBJECTIVES: A rapid and convenient approach for the detection of the most common CYP21 gene mutations in patients with congenital adrenal hyperplasia (CAH) with classical forms of 21-hydroxylase deficiency was used. In addition, a new semiquantitative strategy for the detection of del8-bp was designed. These procedures were used for prenatal diagnosis and genotype-phenotype correlation in northeastern Iran. Design: Molecular analysis of the CYP21 gene for the detection of the 9 most common mutations (CYP21gene deletion, P30L, i2g, del-8bp, I172N, E6 cluster, V281L, Q318X and R356W) was performed on 30 CAH patients and for prenatal diagnosis in 2 cases. METHODS: Restriction fragment length polymorphism, amplification-created restriction sites, allele-specific polymerase chain reaction (PCR) and semiquantitative PCR were performed. RESULTS: We characterized 90% of the CAH chromosomes. The most frequent mutations in the CYP21 gene were del-CYP21 (25%), I172N (22%) and i2g (15%). Unlike in other ethnic groups, there was no R356W mutation, however, a higher rate of del-8bp (10%) was found in our population. Wealso found 6 complex alleles in our patients. For 2 families prenatal CYP21 gene analysis resulted in the diagnosis of healthy fetuses and termination of dexamethasone treatment in the 15th week of gestation. Genotype-phenotype correlation was observed. The rate of homozygosity (50%) was greater than the predicted values due to the higher rate of parental consanguinity in our population. CONCLUSIONS: These molecular procedures proved to be sensitive and rapid for the detection of the most common mutations of the CYP21 gene and prenatal diagnosis. Increased 17-hydroxyprogesterone, found in neonatal CAH screening, can be confirmed by these mutation analyses.  相似文献   

12.
Summary The possibility of using TaqI restriction fragment length polymorphism (RFLP) analysis of the HLA-B locus and the HLA-DR-DQ subregions, flanking the 21-hydroxylase genes, for predicting disease in siblings of children with 21-hydroxylase deficiency was analyzed in 12 nuclear families with at least one affected child and a total of 18 at-risk off-spring. As part of the study allelic TaqI HLA-B RFLP patterns were determined in homozygous cell lines and families. The frequencies of individuals homozygous for TaqI allelic patterns of the different investigated HLA loci, each locus alone and in various combinations, were determined in 100 random controls. In all 12 families it was possible to make correct genetic diagnosis by the use of only one restriction enzyme, TaqI, and two locus-specific HLA cDNA probes, HLA-B and -DRB. In all families four haplotypes were obtained. Thus, affected siblings as well as carriers could be identified. Seven of the eight sibling pairs concordant for 21-hydroxylase deficiency had pairwise identical TaqI HLA-B-DRB-DQA-DQB haplotypes. The last disease-concordant sibling pair had inherited different haplotypes from their mother, who had nonclassical 21-hydroxylase deficiency. None of the ten healthy children shared both haplotypes with their affected sibling(s). Early prenatal suppression of the fetal adrenal cortex with fluorinated corticosteroids can prevent virilization of female fetuses with 21-hydroxylase deficiency. In most cases RFLP analysis of the 21-hydroxylase genes is not informative enough for prenatal diagnosis. Our results from the present retrospective family study indicate that TaqI HLA-B and -DRB RFP analysis will be a valuable tool for first trimester assessment of 21-hydroxylase deficiency. TagI HLA-B and -DRB RFLP analysis can be performed on DNA from chorionic villi biopsies obtained in the 8th week of pregnancy. Supplemented with sex determination, early withdrawal of prophylactic steroid therapy will thus be feasible when the mother carries a male or an unaffected female fetus.  相似文献   

13.
《Endocrine practice》2015,21(4):383-389
Objective: The American Association of Clinical Endocrinologists Adrenal Scientific Committee has developed a series of articles to update members on the genetics of adrenal diseases.Methods: Case presentation, discussion of literature, table, and bullet point conclusions.Results: The congenital adrenal hyperplasia (CAH) syndromes are autosomal recessive defects in cortisol biosynthesis. The phenotype of each CAH patient depends on the defective enzyme and the severity of the defect. Clinical manifestations derive from both failure to synthesize hormones distal to the enzymatic block, as well as consequences from cortisol precursor accumulation proximal to the block, often with diversion to other biologically active steroids. The most common form of CAH is 21-hydroxylase deficiency, which occurs in the classic form in 1 in 16,000 newborns and in a milder or nonclassic form in at least 1 in 1,000 people.Conclusion: This article reviews the various forms of CAH and pitfalls in the diagnosis and treatment of these conditions.Abbreviations: 11OHD = 11-hydroxylase deficiency 17OHD = 17-hydroxylase deficiency 17OHP = 17-hydroxyprogesterone 21OHD = 21-hydroxylase deficiency 3βHSD = 3β-hydroxysteroid dehydrogenase CAH = congenital adrenal hyperplasia CST = cosyntropin stimulation test CYP17A1 = cytochrome P450 17A1 (steroid 17-hydroxylase/17,20-lyase) DHEAS = dehydroepiandrosterone sulfate DSD = disorder of sex development LCAH = lipoid congenital adrenal hyperplasia NBS = newborn screening NCAH = nonclassic CAH PCOS = polycystic ovary syndrome PORD = P450-oxidoreductase deficiency  相似文献   

14.
Steroid 21-hydroxylase is a key enzyme of glucocorticoid and mineralocorticoid biosynthesis in the adrenal gland that belongs to the family of microsomal cytochrome P450. The steroid 21-hydroxylase deficiency is the most frequent cause of the congenital adrenal hyperplasia. The human steroid 21-hydroxylase (CYP21 A) and its mutant variant (C 169R) found previously in patient with the classical congenital adrenal hyperplasia were synthesized for the first time in the insect cell lines Sf9 and Hi5 infected by recombinant baculoviruses. Under optimal conditions the level of CYP21A2 production in insect cells achieves 28% of the total microsomal protein. C169R mutation does not effect the synthesis of CYP21 A2 in insect cells and does not prevent the incorporation of the enzyme into the membranes of endoplasmic reticulum. Functional analysis of the mutant enzyme in vitro suggested the virtually complete lack of catalytic activity towards two substrates - progesterone and 17-hydroxyprogesterone.  相似文献   

15.
It is not clear if an increase in intra-adrenal cortisol is required to mediate the actions of adrenocorticotropic hormone (ACTH) on adrenal growth and steroidogenesis during the prepartum stimulation of the fetal pituitary-adrenal axis. We infused metyrapone, a competitive inhibitor of cortisol biosynthesis, into fetal sheep between 125 and 140 days of gestation (term = 147 +/- 3 days) and measured fetal plasma cortisol, 11-desoxycortisol, and ACTH; pituitary pro-opiomelanocortin mRNA and adrenal expression of ACTH receptor (melanocortin type 2 receptor), steroidogenic acute regulatory protein (StAR), 11beta-hydroxysteroid dehydrogenase type 2 (11betaHSD2), cytochrome P450 cholesterol side-chain cleavage (CYP11A1), cytochrome P450 17-hydroxylase (CYP17), 3beta-hydroxysteroid dehydrogenase, and cytochrome P450 21-hydroxylase mRNA; and StAR protein in the fetal adrenal gland. Plasma ACTH and 11-desoxycortisol concentrations were higher (P < 0.05), whereas plasma cortisol concentrations were not significantly different in metyrapone- compared with vehicle-infused fetuses. The ratio of plasma cortisol to ACTH concentrations was higher (P < 0.0001) between 136 and 140 days than between 120 and 135 days of gestation in both metyrapone- and vehicle-infused fetuses. The combined adrenal weight and adrenocortical thickness were greater (P < 0.001), and cell density was lower (P < 0.01), in the zona fasciculata of adrenals from the metyrapone-infused group. Adrenal StAR mRNA expression was lower (P < 0.05), whereas the levels of mature StAR protein (30 kDa) were higher (P < 0.05), in the metyrapone-infused fetuses. In addition, adrenal mRNA expression of 11betaHSD2, CYP11A1, and CYP17 were higher (P < 0.05) in the metyrapone-infused fetuses. Thus, metyrapone administration may represent a unique model that allows the investigation of dissociation of the relative actions of ACTH and cortisol on fetal adrenal steroidogenesis and growth during late gestation.  相似文献   

16.
Summary The urinary excretion of steroids was studied in 8 parents of children with congenital adrenal hyperplasia due to 21-hydroxylase deficiency of the simple virilizing and of the salt-losing type. Eight parents of normal children served as controls. 24-hour urines before and after the injection of 40 IU of ACTH were fractionated using gas liquid chromatography on glass capillary columns.Before stimulation no excretion of pregnanetriolone was detected in heterozygous and in normal parents. Following ACTH only heterozygotes showed an excretion of pregnanetriolone in the urine. This averaged 289 g per 24 h.Employing gas liquid chromatography on glass capillary columns heterozygous carriers of congenital adrenal hyperplasia due to 21-hydroxylase deficiency may reliably be detected by their increased urinary excretion of pregnanetriolone following ACTH.Supported by Deutsche Forschungsgemeinschaft, SFB 87, Project C3.Presented in part at the Annual Meeting of the European Society for Paediatric Research, Budapest, August 21st–24th, 1975.  相似文献   

17.
The authors report the case of a 29-year-old man with bilateral testicular adrenal-like tumors in a context of congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency. Inadequate suppression of ACTH secretion is a dominant etiological factor in the development of testicular masses in CAH. Destruction of the testicular tubules by the adrenal rests and longstanding suppression of the pituitary-gonadal axis can lead to infertility. The presence of testicular adrenal rests must be investigated in any man with CAH due to 21-hydroxylase deficiency and infertility. Similarly, it is important to investigate possible 21-hydroxylase deficiency in patients with bilateral testicular tumors.  相似文献   

18.
Plasma levels of dehydroepiandrosterone-sulfate (DHEA-S), dehydroepiandrosterone (DHEA), delta 4-androstenedione (delta 4), testosterone and 17 alpha-OH-progesterone (17-OH-P) were studied in 58 samples collected in 18 patients with congenital adrenal hyperplasia due to 21-hydroxylase deficiency, during long-term ambulatory treatment with hydrocortisone. At each visit the patients were classified as being either in good control (GC) or in poor control (PC), based on well-defined clinical, auxological and biochemical criteria. The results were analyzed in relation to the degree of control and to chronological age (CA), bone age (BA), body surface (BS) and pubertal development. The most clear distinction between the children with GC and those with PC is found for DHEA-S (p less than 0.001 for BA). The majority of the DHEA-S values in the children with GC are closely grouped and significantly below the normal limits for CA, BA, BS and pubertal stage (p less than 0.001). In contrast, the PC children have wide-spread values, most of them being within or above the normal limits. The difference between GC and PC is also significant for testosterone (p less than 0.01) and delta 4 (p less than 0.05), but not for DHEA. Of the five steroids studied, DHEA-S is the most specific, whereas testosterone is the most sensitive and especially useful in girls and in prepubertal boys. delta 4 and 17-OH-P are almost as sensitive as DHEA-S, but they are less specific. DHEA is the less valid criterium.  相似文献   

19.
Late-onset adrenal hyperplasia in north Indian hirsute women   总被引:1,自引:0,他引:1  
The occurrence of late-onset congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency was studied in 60 consecutive hirsute women by means of adrenocorticotrophin (ACTH)-stimulated serum 17-hydroxyprogesterone (17-OHP) levels. Five (8.3%) women had an exaggerated response (ACTH-stimulated 17-OHP 3,160 +/- 560 ng/dl). All of them had regular periods and 3 were virilized. The other 2 were indistinguishable from those with idiopathic hirsutism or polycystic ovarian disease.  相似文献   

20.
C H Shackleton  J Homoki  N F Taylor 《Steroids》1987,49(4-5):295-311
21-Hydroxypregnenolone and its metabolite 5-pregnene-3 beta, 20 alpha 21-triol have been measured in the sulfate fraction of neonatal urine. These two steroids are the major two 21-hydroxylated 5-pregnenes produced by neonates and are almost exclusively excreted as disulfates. The excretions of these steroids by normal infants and infants with 21-hydroxylase deficiency were compared. In addition to measurement of the absolute excretion, the excretion relative to the total 3 beta-hydroxy-5-ene output was also determined. The results show that 21-hydroxypregnenolone excretion is highly elevated in 21-hydroxylase deficiency (affected, mean 887 micrograms/24 h, range 453-1431 micrograms/24 h; normal, mean 117 micrograms/24 h, range 17-263 micrograms/24 h), but when compared to excretion of other delta 5 steroids the excretion is slightly low [(21-hydroxypregnenolone + 5-pregnene-3 beta, 20 alpha, 21-triol)/total 3-beta-hydroxy-5-ene steroids, 2.9% affected; 3.6% normal]. This difference was not statistically significant. There is thus no evidence that the 21-hydroxylase acting on pregnenolone is deficient in congenital adrenal hyperplasia. The explanation of the normal activity of "pregnenolone 21-hydroxylase," although not clearly defined, is probably associated with two recent findings by other workers: (a) that the human fetus has an active 21-hydroxylase distinct from the adrenal enzyme and (b) that a 21-hydroxylase structurally very different from the adrenal enzyme, with high activity towards pregnenolone (but no activity towards 17-hydroxyprogesterone), has been isolated from rabbit hepatic microsomes.  相似文献   

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