Search results
Results from the WOW.Com Content Network
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]
The HPA axis also interacts with the immune system through increased secretion of ACTH at the presence of certain molecules of the inflammatory response. [4] Mineralocorticoid secretion is regulated mainly by the renin–angiotensin–aldosterone system (RAAS), the concentration of potassium, and to a lesser extent the concentration of ACTH. [4]
In the adrenal glands, it is likely involved in the paracrine regulation of aldosterone secretion; in the heart and vasculature, it may be involved in remodeling or vascular tone; and in the brain, where it is largely independent of the circulatory RAS, it may be involved in local blood pressure regulation.
The opposite mechanism is called transrepression. The hormone receptor without ligand binding interacts with heat shock proteins and prevents the transcription of targeted genes. Aldosterone and cortisol (a glucosteroid ) have similar affinity for the mineralocorticoid receptor; however, glucocorticoids circulate at roughly 100 times the level ...
Secretion is typically regulated by the hypothalamus which secretes corticotropin-releasing hormone (CRH) to the pituitary gland, stimulating the pituitary to secrete adrenocorticotropic hormone (ACTH). ACTH then travels to the adrenal glands and induces the release of cortisol into the bloodstream. [7] In Cushing's syndrome, this process ...
Schematic of the HPA axis (CRH, corticotropin-releasing hormone; ACTH, adrenocorticotropic hormone) Hypothalamus, pituitary gland, and adrenal cortex The hypothalamic–pituitary–adrenal axis (HPA axis or HTPA axis) is a complex set of direct influences and feedback interactions among three components: the hypothalamus (a part of the brain located below the thalamus), the pituitary gland (a ...
It selectively stimulates secretion of aldosterone. The secretion of aldosterone has a diurnal rhythm. Control of aldosterone release from the adrenal cortex: [citation needed] The role of the renin–angiotensin system: Angiotensin is involved in regulating aldosterone and is the core regulator. Angiotensin II acts synergistically with potassium.