Key Event Title
|Level of Biological Organization|
Key Event Components
Key Event Overview
AOPs Including This Key Event
|AOP Name||Role of event in AOP|
|Cyp17A1 inhibition leads to undescended testes in mammals||KeyEvent|
Key Event Description
17-OH-progesterone is the direct precursor of androstenedione, a reduction in its synthesis results in a decrease in androstenedione levels. Androstenedione is defined as an obligatory intermediate in sex steroid biosynthesis being the precursor of steroid hormones like testosterone and estradiol. 12
How It Is Measured or Detected
Competitive immunoenzymatic colorimetric methods (ELISA) for quantitative determination of 17-OH-progesterone and androstenedione concentration in serum or plasma are available.
Progesterone and androstenedione synthesis can be monitored using radiolabeled steroid precursor in association with High Performance Liquid Chromatography (HPLC). During synthesis, steroids will incorporate the radioactive label which can be afterwards, used for quantification. First of all, HPLC combined with internal standards can be used for steroids collection, fractionation and identification. Once separated from the other steroids, progesterone and androstenedione can be finally quantified using liquid scintillation spectrometry.
Domain of Applicability
1 Miller Walter L. (1988) Molecular Biology of Steroid Hormone Synthesis. Endocrine Reviews, 9(3): 295-318. https://doi.org/10.1210/edrv-9-3-295
2 Liu Y., Yao ZX., and Papadopoulos V. (2005) Cytochrome P450 17α Hydroxylase/17,20 Lyase (CYP17) Function in Cholesterol Biosynthesis: Identification of Squalene Monooxygenase (Epoxidase) Activity Associated with CYP17 in Leydig Cells. Molecular Endocrinology, 19(7): 1918-1931 https://doi.org/10.1210/me.2004-0271