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Aldosterone is the primary of several endogenous members of the class of mineralocorticoids in humans. [citation needed] Deoxycorticosterone is another important member of this class. Aldosterone tends to promote Na + and water retention, and lower plasma K + concentration by the following mechanisms:
Testosterone is converted to 5-DHT by 5alpha-reductase, usually with in the target tissues of 5-DHT because of the need for high concentrations of 5-dht to produce the physiological effects. Aldosterone: mineralocorticoid: adrenal cortex (zona glomerulosa) MR: Increase blood volume by reabsorption of sodium in kidneys (primarily)
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.
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).
The innermost layer of the cortex, the zona reticularis, produces androgens that are converted to fully functional sex hormones in the gonads and other target organs. [4] The production of steroid hormones is called steroidogenesis, and involves a number of reactions and processes that take place in cortical cells. [5]
In the adrenal cortex, angiotensin II acts to cause the release of aldosterone. Aldosterone acts on the tubules (e.g., the distal convoluted tubules and the cortical collecting ducts) in the kidneys, causing them to reabsorb more sodium and water from the urine. This increases blood volume and, therefore, increases blood pressure.
The enzyme aldosterone synthase (also known as CYP11B2) acts in this location [3] [4] The expression of neuron-specific proteins in the zona glomerulosa cells of human adrenocortical tissues has been predicted and reported by several authors [5] [6] [7] and it was suggested that the expression of proteins like the neuronal cell adhesion ...
These enzymes are nearly identical (they share 11β-hydroxylation and 18-hydroxylation functions), but aldosterone synthase is also able to perform an 18-oxidation. Moreover, aldosterone synthase is found within the zona glomerulosa at the outer edge of the adrenal cortex; 11β-hydroxylase is found in the zona fasciculata and zona glomerulosa.