8 results match your criteria: "C-17 Hydroxylase Deficiency"
An insect-specific P450 oxidative decarbonylase for cuticular hydrocarbon biosynthesis.
Proc Natl Acad Sci U S A
September 2012
Department of Biochemistry and Molecular Biology, University of Nevada, Reno, NV 89557, USA.
Article Synopsis
- * Researchers discovered that a P450 enzyme (CYP4G family) in insects transforms aldehydes into hydrocarbons, which is crucial for their survival and prevents desiccation.
- * This enzymatic process differs from that in cyanobacteria, and the CYP4G enzymes have been vital for insect evolution, enabling them to thrive on land.
Other conceivable renditions of some of the oxidative processes used in the biosynthesis of steroid hormones.
J Steroid Biochem Mol Biol
September 2006
Department of Obstetrics and Gynecology, Institute for Health Sciences, St. Luke's-Roosevelt Hospital Center, 432 West 58 Street, New York, NY 10019, USA.
Article Synopsis
- The generally accepted version (GAV) of steroid hormone biosynthesis is based on artificial lab experiments and may not accurately reflect what happens in living organisms (in vivo), relying on untested assumptions that create uncertainty.
- This text proposes alternative processes in steroid hormone production, suggesting that cytochrome P-450 enzymes introduce dioxygen into precursors to create reactive oxygen species instead of stable hydroxylated compounds as traditionally thought.
- The new model implies specific oxygenated species act as intermediates for producing different hormones, which may help in understanding genetic enzyme deficiencies related to adrenal and ovarian function.
Ablation of the otcC gene encoding a post-polyketide hydroxylase from the oxytetracyline biosynthetic pathway in Streptomyces rimosus results in novel polyketides with altered chain length.
J Biol Chem
November 2005
Department of Bioscience, University of Strathclyde, Glasgow, Scotland, UK.
Article Synopsis
- * A genetic modification in S. rimosus, which disrupted the otcC gene, led to the production of a novel polyketide, showing that otcC is crucial for synthesizing the correct length of OTC.
- * A mutant version of otcC was created and tested, revealing that while it couldn't function on its own, incorporating it back into the S. rimosus chromosome restored the production of the 19-carbon backbone necessary for OTC synthesis, highlighting its importance in the
Disorders of steroid 17 alpha-hydroxylase deficiency.
Endocrinol Metab Clin North Am
June 1994
Department of Medicine, Escola Paulista de Medicina, São Paulo, Brazil.
The human P450c17 alpha gene (CYP17) is a single copy gene located in chromosome 10, consisting of 8 exons and 7 introns. 17 alpha-Hydroxylase/17,20-lyase deficiency is one of two hypertensive forms of congenital adrenal hyperplasia and is inherited as an autosomal recessive trait; although rare, it probably exists with twice the frequency of the 11 beta-hydroxylase deficiency. Deficient 17 alpha-hydroxylation of pregnenolone and progesterone and subsequent deficiency of the cleavage of the C-17,20 carbon bond result in the absence of sex hormone formation in both the adrenal glands and the gonads, causing hypogonadism and male pseudohermaphroditism.
View Article and Find Full Text PDFPituitary-ovarian responses to nafarelin testing in the polycystic ovary syndrome.
N Engl J Med
March 1989
Department of Obstetrics/Gynecology, University of Chicago Pritzker School of Medicine, IL.
Article Synopsis
- The study examined responses to the hormone nafarelin in patients with polycystic ovary syndrome (PCOS) compared to normal men and women.
- Women with PCOS showed an abnormal hormonal response pattern, specifically higher luteinizing hormone and lower follicle-stimulating hormone reactions relative to normal women.
- Results indicate that women with PCOS have masculinized responses to hormone stimulation, suggesting abnormalities in ovarian hormonal regulation.
Effects of tocopherol depletion on the regional differences in adrenal microsomal lipid peroxidation and steroid metabolism.
Endocrinology
August 1988
Department of Biomedical Sciences, University of Illinois College of Medicine, Rockford 61107.
Article Synopsis
- * Depleting alpha-tocopherol through diet increased LP in the outer zone while having little impact in the inner zone, indicating that tocopherol is crucial for maintaining zonal differences in LP.
- * Additionally, a deficiency in tocopherol reduced the activity of steroid-synthesizing enzymes in the outer zone, suggesting that alpha-tocopherol helps safeguard these enzymes from oxidative damage and affects how the adrenal cortex functions.
Reduced activity of androgen biosynthesis in the testes of rats with analbuminemia.
J Steroid Biochem
April 1986
Article Synopsis
- Steroid metabolism in Nagase Analbuminemia Rats (NAR) shows lower total testosterone levels compared to normal rats, despite similar levels of free testosterone, luteinizing hormone (LH), and follicle-stimulating hormone (FSH).
- The rate at which testosterone is cleared from the plasma and its half-life are relatively similar between NAR and normal rats, suggesting that differences in testosterone levels are not due to elimination speed.
- Enzyme activity tests indicate that NAR rats have significantly reduced testosterone synthesis capabilities in the testes, contributing to their lower serum testosterone concentrations.
Article Synopsis
- A patient's steroid metabolic profile was examined using gas chromatography and mass spectrometry to identify a potential blockage in steroid production.
- The analysis indicated a blockage specifically at the 17 alpha-hydroxylase step, as no steroids with a hydroxy group at C-17 were detected.
- The use of advanced gas chromatography-mass spectrometry provided clearer diagnostic results compared to traditional methods, and the findings were compared with normal cases and other instances of 17 alpha-hydroxylase blockage.