fludrocortisone brands

Molecular formula: C21H29FO5

The main endogenous mineralocorticoid, aldosterone, is produced in the zona glomerulosa of the adrenal cortex - it acts on mineralocorticoid receptors in the kidneys to increase sodium reabsorption and potassium excretion, which in turn helps to regulate plasma electrolyte composition and blood pressure. In conditions of adrenal insufficiency, such as Addison’s disease, aldosterone is not produced (or is produced in insufficient quantities) and must be replaced by exogenous mineralocorticoids such as fludrocortisone. Fludrocortisone binding to mineralocorticoid receptors causes alterations to DNA transcription and translation of proteins that result in an increased density of sodium channels on the apical side of renal tubule cells and an increased density of Na⁺-K⁺-ATPase on the basolateral side. These increases in receptor density result in increased plasma sodium concentrations, and thus increased blood pressure, as well as a decreased plasma potassium concentration. Fludrocortisone may also exert a direct effect on plasma sodium levels via action at the Na⁺-H⁺ exchanger found in the apical membrane of renal tubule cells. Fludrocortisone also acts on glucocorticoid receptors, albeit with a much lower affinity - the glucocorticoid potency of fludrocortisone is approximately 5-10 times that of endogenous cortisol, whereas its mineralocorticoid potency is 200-400 times greater. At the cellular level, corticosteroids diffuse across cell membranes and complex with specific cytoplasmic receptors. These complexes then enter the cell nucleus, bind to DNA (chromatin), and stimulate transcription of mRNA (messenger RNA) and subsequent protein synthesis of various enzymes thought to be ultimately responsible for the physiological effects of these hormones. Mineralocorticoids act on the distal tubules to increase potassium excretion, hydrogen ion excretion, and sodium reabsorption and subsequent water retention. Cation transport in other secretory cells is similarly affected; excretion of water and electrolytes by the large intestine and by salivary and sweat glands is also altered, but to a lesser extent.

Source: PubChem (NCBI) · compound 31378