PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Hydroxyprogesterones”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 541 records · Page 30Linked to original sources
PubMed1971

Studies on an extract of rat testicular microsomal fraction that catalyses the transformation of progesterone into 17-hydroxyprogesterone and androgens.

The supernatant obtained by centrifugation of Triton N-101-treated freeze-dried rat testicular microsomal fraction at 105000g(av.) for 2h transformed progesterone into testosterone via 17-hydroxypregn-4-ene-3,20-dione and androst-4-ene-3,17-dione. Hydroxylation at C-17 of 3beta-hydroxypregn-5-en-20-one and deoxycorticosterone was not observed. Non-haem iron protein, cytochrome P-450 and material with NADPH dehydrogenase activity were precipitated by 40% saturation of the supernatant with ammonium sulphate; however, it was not possible to establish the participation of these substances in the 17alpha-hydroxylase and side-chain-cleavage activities also present in the precipitate. The results of gel-filtration chromatography indicated that the Triton N-101 extract consisted primarily of a suspension of small particles of microsomes and that the progesterone 17-hydroxylase and the 17-hydroxypregn-4-ene-3,20-dione side-chain-cleavage enzyme were not in true solution.

Androgens↗
PubMed2000

Influence of different genotypes on 17-hydroxyprogesterone levels in patients with nonclassical congenital adrenal hyperplasia due to 21-hydroxylase deficiency.

OBJECTIVE: The diagnosis of the nonclassical form of 21-hydroxylase (NC-21OH) deficiency, established before molecular studies, is based on basal 17OH-progesterone (17OH-P) values > 15 nmol/l or ACTH-stimulated 17OH-P values > 30 nmol/l. This disease is caused by mutations in the structural gene that can be grouped into three categories: A, B and C, according to the predicted level of enzymatic activity. So, the genotype of the nonclassical form is a combination of mutations that cause moderate impairment of enzymatic activity in one allele and mutations which cause total (A), severe (B: 3%) or moderate (C: 20-60%) impairment of enzymatic activity in the other allele. DESIGN: We analysed the influence of the different genotypes on 17OH-P levels in 58 patients with the nonclassical form of 21OH deficiency. RESULTS: After screening for 18 mutations through Southern blotting, allele-specific polymerase chain reaction (PCR) and enzyme restriction, mutations were identified in 73% of the alleles. Patients with mutations identified in both alleles were divided into groups A/C (n = 18), B/C (n = 3) and C/C (n = 15). The basal and ACTH-stimulated 17OH-P levels in patients with A/C genotype ranged from 1.2 to 153 and 72-363 nmol/l, and in C/C genotype ranged from 0.9 to 72 and 51-363 nmol/l, respectively (P < 0.05 for stimulated levels). The lowest value of ACTH-stimulated 17OH-P levels in fully genotyped patients was 51 nmol/l. Patients with the A/C genotype presented androgen excess symptoms earlier than patients with the C/C genotype. CONCLUSIONS: These data suggest an influence of genotype on phenotype and on 17OH-P levels. The high frequency of unidentified mutant alleles in nonclassical 21-hydroxylase deficiency suggests that ACTH-stimulated values of 17OH-P between 30 and 51 nmol/l have overestimated this diagnosis. Genotyping more patients with nonclassical 21-hydroxylase deficiency will help to redefine the cut-off value for ACTH-stimulated 17OH-P for correct diagnosis of this disease.

17-alpha-Hydroxyprogesterone↗
PubMed1996

The use of electrochemistry for the synthesis of 17 alpha-hydroxyprogesterone by a fusion protein containing P450c17.

A method has been developed for the commercial application of the unique oxygen chemistry catalyzed by various cytochrome P450s. This is illustrated here for the synthesis of hydroxylated steroids. This method requires the preparation of large amounts of enzymatically functional P450 proteins that can serve as catalysts and a technique for providing electrons at an economically acceptable cost. To generate large amounts of enzymatically active recombinant P450s we have engineered the cDNAs for various P450s, including bovine adrenal P450c17, by linking them to a modified cDNA for rat NADPH-P450 reductase and placing them in the plasmid pCWori+. Transformation of E. coli results in the high level expression of an enzymatically active protein that can be easily purified by affinity chromatography. Incubation of the purified enzyme with steroid in a reaction vessel containing a platinum electrode and a Ag/AgCl electrode couple poised at -650 mV, together with the electromotively active redox mediator, cobalt sepulchrate, results in the 17 alpha-hydroxylation of progesterone at rates as high as 25 nmoles of progesterone hydroxylated/min/nmole of P450. Thus, high concentrations of hydroxylated steroids can be produced with incubation conditions of hours duration without the use of costly NADPH. Similar experiments have been carried out for the generation of the 6 beta-hydroxylation product of testosterone (using a fusion protein containing human P450 3A4). It is apparent that this method is applicable to many other P450 catalyzed reactions for the synthesis of large amounts of hydroxylated steroid metabolites. The electrochemical system is also applicable to drug discovery studies for the characterization of drug metabolites.

17-alpha-Hydroxyprogesterone↗