Apparent mineralocorticoid excess syndrome Apparent mineralocorticoid excess syndrome Apparent mineralocorticoid excess (AME) is an autosomal recessive disorder causing hypertension (high blood pressure) and hypokalemia (abnormally low levels of potassium). It was found by Dr Maria I. New at Weil Cornell Hospital in New York City. It results from mutations in the "HSD11B2" gene, which encodes the kidney isozyme of 11β-hydroxysteroid dehydrogenase type 2. In an unaffected individual, this isozyme inactivates circulating cortisol to the less active metabolite cortisone. The inactivating mutation leads to elevated local concentrations of cortisol in the aldosterone sensitive tissues like the kidney. Cortisol at high concentrations can cross-react and activate
Subcommissural organ neuronal cell bodies within the subcommissural organ, although the specialized cells receive some innervation from outside neurons. Ependymal cells secrete high molecular mass glycoproteins into the cerebrospinal fluid, in which the bulk of them condense to form a filamentous structure named Reissner’s fiber. The subcommissural organ/Reissner’s fiber complex is thought to be involved in the reabsorption and circulation of the cerebrospinal fluid, and with functions related to electrolyte and water balance. One of the proteins secreted by the subcommissural organ, and which is present in Reissner’s fiber, is spondin. SCO-spondin is a “giant” (5000 amino acids) glycoprotein (thrombospondin superfamily) found