Changes in Na ⁺ and K ⁺ transport by the kidney when dietary K ⁺ intake is high. + and − symbols indicate increased and decreased transepithelial movement of ions, respectively. Solid lines represent well-established signaling systems for regulating transport under these conditions. Dashed lines represent pathways that regulate transport but have not been shown to be involved in the response to increased K⁺ intake. The net result is that urinary K⁺ excretion is enhanced while Na⁺ excretion remains constant.