Hyperaldosteronism (excessive aldosterone release) can be caused by many disease states including tumours in the adrenal gland. By now, we should be familiar with how this will affect sodium balance and blood pressure, but how would hyperaldosteronism affect potassium levels and why? Select one potassium effect (a or b) and one cause (c-f).
- The patient will become hyperkalemic
- The patient will become hypokalemic
- Aldosterone increases sodium reabsorption in the proximal tubule. Increased sodium reabsorption increases water reabsorption, which then establishes a concentration gradient to increase potassium reabsorption.
- Aldosterone increases sodium reabsorption in the collecting duct. Increased sodium reabsorption increases water reabsorption, which then establishes a concentration gradient to increase potassium reabsorption.
- Aldosterone increases sodium reabsorption in the collecting duct by increasing expression of EnaCs, sodium/potassium exchangers, and sodium/hydrogen exchangers on the luminal membrane. Thus as sodium reabsorption increases, potassium secretion increases.
- An increase in sodium reabsorption reduces activity of the sodium/potassium pump. This increases ECF potassium concentrations, increasing potassium clearance.