Potassium preserves endothelial function and enhances aortic compliance in Dahl rats

Abstract

It has recently been proposed that in rat models of genetic hypertension, supplemental dietary potassium preserves release of endothelium-derived relaxing factor independently of its capacity to either attenuate hypertension or increase plasma potassium. To test this hypothesis in Dahl salt-sensitive rats given sodium chloride (4%) for 3 weeks, we supplemented dietary potassium (2.1%) with either KCl (n=16) or KHCO3 (n=16). Compared with unsupplemented rats (n=16), rats supplemented with either potassium salt had a lower mean arterial pressure and a greater release of endothelium-derived relaxing factor, as assessed from acetylcholine-induced relaxation of precontracted aortic rings. However, the maximum relaxation response to acetylcholine correlated inversely with blood pressure (r=-.82, P <001) groups but also in unsupplemented rats (r=-,86, P