Gut-kidney kaliuretic signaling: looking forward to feeding.

Preston et al. report urinary potassium excretion in healthy subjects in response to an acute potassium load with or without a meal. The investigators show a rapid kaliuretic response that occurs independently of the serum potassium and plasma aldosterone concentration, and that persists in the presence of a mineralocorticoid receptor blocker. This Commentary puts these data in perspective by reviewing the current understanding of the feedback and feedforward systems that regulate renal potassium excretion.