Pseudohypoaldosteronism
When Pseudohypoaldosteronism is a group of genetic defects in functioning aldosterone secretion the clinical picture of a hypoaldosteronism trigger. The dominant form of type I is a loss of function of the mineralocorticoid receptor , while the recessive form is a defect in the ENaC ( epithelial sodium channel ). A Pseudohypoaldosteronism of type II is the absence of a functional Wnk-lysine kinase .
Both forms of 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 connecting tubule and collecting tube of the kidney . Insufficient ENaC activity in these segments leads to increased sodium excretion in the urine , which would actually correspond to the clinical picture of hypoaldosteronism . Aldosterone , which should normally stimulate the incorporation of ENaC into the apical plasma membrane , is present in normal to increased concentrations, but cannot work due to the mutations. The increased sodium excretion results in increased fluid loss, which causes severe hypovolemia . The decreased sodium reabsorption in the main cells of the collecting tube causes the loss of the electrochemical gradient, which in turn reduces the secretion of potassium and hydrogen and thus causes hyperkalemia and acidosis .
In type II hyperkalemia and acidosis also occur, but instead of a drop in blood pressure, hypertension occurs . Since the NaCl cotransporter is not inhibited here , it absorbs sodium and chloride ions to a large extent , and water follows osmotically .
Individual evidence
- ↑ Marshal S. Runge, Cam Patterson: Principles of Molecular Medicine , 2nd edition, pp. 613 ff., Humana Press, New York 2006
- ↑ Jian Xie, Leonard Craig, Melanie H. Cobb, Chou-Long Huang: Role of with-no-lysine [K] kinases in the pathogenesis of Gordon's syndrome . In: Pediatric Nephrology , 2006, 21: pp. 1231-1236, PMID 16683163
