Td 88239

All experimental procedures were approved by the University of Pittsburgh Institutional Animal Care and Use Committee. All methods were performed in accordance with the relevant guidelines and regulations. Female Sprague-Dawley rats (250–300 g; Envigo) were used throughout. Rats were housed under 12 h light/12 h dark cycle and fed a regular diet, a low K⁺ (LK) diet (0.0015–0.003% w/w K⁺ content, Envigo TD.88239) or a control K⁺ diet (1.0% w/w K⁺ content, Envigo TD.88238) ad libitum with free access to water. Animals were randomized to blinded treatment and control groups. The stage of the estrous cycle was not monitored. Rats were euthanized by CO₂ inhalation, followed by a thoracotomy.

Normal Na⁺, K⁺‐deficient diets (TD.88239, 15–30 ppm [0.0015%–0.003%] K⁺, 0.3% Na⁺, and 0.45% Cl⁻, 0.06% Ca²⁺) and high Na⁺, 0.04% K⁺ diets (TD.210231 0.04% K⁺, 2.36% Na⁺, 3.65% Cl⁻ 0.1%, Ca²⁺) diets were purchased from Envigo. Animals were treated for 3 weeks. Contents are also listed in Table 1.