Aldosteron und Niere – eine komplexe Interaktion

Aldosterone is a hormone with a dual effect on the kidneys. On the one hand, it is part of a regulatory system for maintaining the sodium (= volume) balance; on the other hand, it is jointly responsible for the stability of the potassium balance and the acid–base balance. Disorders of the aldosterone system are therefore characterized by reduced or increased S‑potassium levels and hypo- or hypertension. Aldosterone acts at the so-called aldosterone-sensitive section of the distal tubule of the nephron, where it activates various ion transporters that promote sodium reabsorption and potassium secretion. What is more difficult to understand is that increased aldosterone activity does not always lead to hypokalemia (aldosterone paradox) and that disturbances of (aldosterone-dependent) ion transporters in the distal tubule of the kidney lead to seemingly paradoxical situations in which the extent of aldosterone secretion in the adrenal gland does not match the expected aldosterone effect (pseudo-hypo-/hyperaldosteronism). This can be due to rare monogenetic diseases, but also to acquired causes. The main interactions between aldosterone and the distal tubule section of the kidney are explained using three case studies.