Potassium effects on blood pressure: is the conjugate anion important?

Potassium salts, often in the form of KCl, have had variable hypotensive effects in experimental animals and man. The chloride anion has recently been implicated as the hypertensive agent in salt-sensitive hypertension. We therefore hypothesized that non-chloride salts of potassium would have superior hypotensive effects to KCl. In randomized, double-blind fashion, we administered placebo, KCl (75 mmol/day) or potassium citrate (75 mmol/day) to 24 normotensive adult males. In these subjects, neither KCl nor potassium citrate affected blood pressure, despite urinary verification of potassium supplement intake. Thus, in these experimental circumstances, neither potassium nor its conjugate anion were of importance in lowering blood pressure.