Steroidogenic enzymes definition

role regulat ion     steroidogenic enzyme     enzyme level     steroidogenic cell     normal physiological fluctuation     steroidogenlc enzyme     adrenal cortex     cell-specific expression     final part     hormonal signal     parallel change     steroid oxidoreductase     major type     basal expression     steroidogenlc enzyme varies     cell specific expression     gene expression     major physiological variation     selective activation     trophic hormonal stimulation     steroid output     cytochrome p450     steroidogenic capacity     uring tissue     cell differentiation     steroid hormone biosynthesis     biosynthesis ofspecific steroid     steroidogenic p450s     specific steroid     quantitative capacity     relative role    

The pattern of steroid synthesis in the placenta is complicated by the fact that the placenta is an ‘incomplete endocrine gland’: it lacks the key enzymes required to synthesise the full range of steroid hormones. Most notably, the placenta does not express the CYP17A enzyme necessary to convert progestogens to androgens. As a consequence, for the placenta to synthesise estrogens, it has to work in concert with the fetal adrenal gland and maternal liver, with steroids passing back and forth between the placenta, fetal and maternal circulations. Importantly, 16 α -hydroxyandrostenedione secreted from the fetal zone of the fetal adrenal cortex can, in the placenta, be aromatised to estriol, a unique steroid that is synthesised only by the placenta and that can be used as a surrogate marker to assess the functional status of the fetal adrenal gland.

Steroidogenic enzymes definition

steroidogenic enzymes definition


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