Search results
Results from the WOW.Com Content Network
Aldosterone synthase, also called steroid 18-hydroxylase, corticosterone 18-monooxygenase or P450C18, is a steroid hydroxylase cytochrome P450 enzyme involved in the biosynthesis of the mineralocorticoid aldosterone and other steroids. The enzyme catalyzes sequential hydroxylations of the steroid angular methyl group at C18 after initial 11β ...
18-Hydroxylase (aldosterone synthase) – mineralocorticoid synthesis; 21-Hydroxylase – corticosteroid synthesis; Cytochrome P450 (CYP1, 2, 3) – estrogen metabolism; Hydroxysteroid dehydrogenases (and ketosteroid reductases) 3α-Hydroxysteroid dehydrogenase – androgen, progestogen, and neurosteroid synthesis and metabolism
The outermost layer, the zona glomerulosa is the main site for the production of aldosterone, a mineralocorticoid. The synthesis and secretion of aldosterone are mainly regulated by the renin–angiotensin–aldosterone system. The zona glomerulosa cells express a specific enzyme aldosterone synthase (also known as CYP11B2).
Aldosterone stimulates Na + and water reabsorption from the gut, salivary and sweat glands in exchange for K +. Aldosterone stimulates secretion of H + via the H+/ATPase in the intercalated cells of the cortical collecting tubules; Aldosterone upregulates expression of NCC in the distal convoluted tubule chronically and its activity acutely. [18]
Aldosterone and cortisol (a glucosteroid) have similar affinity for the mineralocorticoid receptor; however, glucocorticoids circulate at roughly 100 times the level of mineralocorticoids. An enzyme exists in mineralocorticoid target tissues to prevent overstimulation by glucocorticoids.
Steroid 21-hydroxylase is a protein that in humans is encoded by the CYP21A2 gene.The protein is an enzyme that hydroxylates steroids at the C21 position on the molecule. [10] [11] Naming conventions for enzymes are based on the substrate acted upon and the chemical process performed.
However, mouse zona glomerulosa cells within adrenal slices spontaneously generate membrane potential oscillations of low periodicity; this innate electrical excitability of these cells provides a platform for the production of a recurrent Ca 2+ channels signal that can be controlled by angiotensin II and extracellular potassium, the 2 major ...
3β-Hydroxysteroid dehydrogenase/Δ 5-4 isomerase (3β-HSD) (EC 1.1.1.145) is an enzyme that catalyzes the biosynthesis of the steroid progesterone from pregnenolone, 17α-hydroxyprogesterone from 17α-hydroxypregnenolone, and androstenedione from dehydroepiandrosterone (DHEA) in the adrenal gland.