Figure 5.

Kinetics of ENaC processing during salt repletion. Mice were fed a low-Na⁺ diet for 1 week. At time 0 they were offered a high- Na⁺ diet as well as saline drinking water. A. Western blot of kidney microsomes at different times after the initiation of the Na⁺ repletion trial. Each lane was loaded with 60 μg of protein from a different animal. Blots were stained for γENaC. B. Abundance of cleaved and full-length forms of γENaC at different times after the initiation of Na⁺ repletion, normalized to values at t = 0. Data for the cleaved form were fit with the equation:

$\mathrm{A}\left(\mathrm{t}\right)=1-\mathrm{B}•(1–\mathrm{e}\mathrm{x}\mathrm{p}(-\mathrm{t}/\mathrm{\tau }\left)\right)$ with B = 0.8 and τ = 5.2 hours.

Data for the full-length form were fit with the equation

$\mathrm{A}\left(\mathrm{t}\right)=1+(\mathrm{A}\mathrm{m}\mathrm{a}\mathrm{x}–1)•(1-\mathrm{e}\mathrm{x}\mathrm{p}(\mathrm{t}/\mathrm{\tau }\left)\right)$ with A_max = 5.0 and τ = 23 hours.

All mice were male.