A situation may arise where a person takes in a large amount of sodium and potassium. The result is that potassium must be excreted while not reabsorbing sodium. The stimulus for aldosterone production is a high potassium. Angiotensin II levels will be low because of the sodium load. The reabsorption of bicarbonate in the proximal tubule is reduced by the potassium load and the reabsorption of chloride in the cortical collecting duct is also reduced leading to the development of the electrical gradient which enhances potassium excretion.