Pseudohypoaldosteronism

When Pseudohypoaldosteronism is a group of genetic defects that cause the clinical picture of a hypoaldosteronism in functioning aldosterone secretion. In the dominant form of type I there is a loss of function of the mineralocorticoid receptor in the recessive form of a defect of the ENaC ( epithelial sodium channel). To a pseudohypoaldosteronism type II is the absence of a functional Wnk -lysine kinase.

Both forms of the type I Pseudohypoaldosteronism result in a reduction in the activity of ENaC ( Epithelial sodium channel ), which plays an important role in sodium reabsorption in the collecting duct and Verbindungstubulus kidney. Due to insufficient ENaC activity in these segments, there is an increased urinary sodium excretion, which would actually match the symptoms of hypoaldosteronism. Aldosterone, which would normally stimulate the incorporation of ENaC in the apical plasma membrane, is normal to an increased concentration exists, but can not function due to the mutations. The increased sodium excretion results in increased fluid loss of what a severe hypovolemia causes. The reabsorption of sodium decreased in the principal cells of the collecting tube causes the loss of the electro- chemical gradient, which in turn reduces the secretion of potassium and hydrogen, thus causing hyperkalemia and acidosis.

Although In type II also occur hyperkalemia and acidosis, but it comes instead of a drop in blood pressure for hypertension. Because here obviates the inhibition of the NaCl cotransporter, this takes on a large scale sodium and chloride ions, water follows osmotically.