Figure 5.

Segmental accounting of whole kidney Na⁺ flows (delivery) and fluxes (transport), in hyperkalemia, with tubuloglomerular feedback (TGF) active. Negative transport values correspond to reabsorptive fluxes. The bars correspond to incremental regulatory responses: open bars denote unregulated hyperkalemia (HK + TGF; A2); backslash bars indicate aldosterone (Aldo) action, a doubling of the density of the epithelial Na⁺ channel and Na⁺-K⁺-ATPase in principal cells (HK + TGF + Aldo; B1); forward slash bars adds an 80% reduction in NaCl cotransporter (NCC) density (HK + TGF + Aldo-NCC; B2); and cross-hatched bars add a halving of ammoniagenesis (HK + TGF + Aldo-NCC-Amm; B3). Proximal delivery and reabsorption are available in Table 6 but are not depicted. CD, collecting duct; CNT, connecting tubule; DCT, distal convoluted tubule; LOH, loop of Henle.