Fig. 6.

Estrogen receptor agonists, DPN and G-1, exhibited time-dependent effects on cell surface abundance of αENaC in L2 cells. Using cell surface biotinylation, we examined the cell surface abundance of αENaC in L2 cells treated with vehicle, 2 nM DPN, or 10 nM G-1 for 30 min (acute) or 24 h (chronic). A: representative blots for the acute experiments are shown. Densitometry was performed to detect relative differences in cleavage products of αENaC at the cell surface (n = 4). B: data for the relative density of the 95-kDa band are shown as means ± SE with vehicle set to 1. G-1 significantly increased the intensity of the 95-kDa band at the apical membrane. C: representative blots for the chronic experiments are shown. Densitometry was performed to detect relative differences in cleavage products of αENaC at the cell surface (n = 4–5). D: data for the relative density of the 60-kDa band are shown as means ± SE with vehicle set to 1. DPN significantly increased apical membrane abundance of the 60-kDa band after 24 h. Differences were analyzed by one-sided z-test. *P < 0.05 vs. vehicle.