Figure 7.

Inhibition of NKA results in disorganized rod OSs of Xenopus laevis. Xenopus tadpoles (NT) were treated with digoxin, which is a specific inhibitor of NKA. Control animals were treated with 0.1% DMSO and were housed in the same conditions. A, Immunofluorescence labeling of photoreceptor OSs using anti-P/rds after 3 or 7 d of either 3.5 μm digoxin treatment or no treatment (Control). Digoxin-treated retinas had fewer and shorter OS structures compared with control retinas; this effect was exacerbated with longer treatment time (compare 3 and 7 d). B, Immunofluorescence labeling of rod OSs using XAP-2 antibody after 3 or 7 d of digoxin treatment. Treated retinas (digoxin) had shorter and fewer OS structures than untreated retinas (Control). C, Representative immunoblot comparing endogenous rhodopsin levels between digoxin-treated and untreated (Untreated) retinas. Mean rhodopsin signal in untreated retinas was standardized to 1.00 (a.u.). The relative values were 1.00 ± 0.31 (n = 6 animals) for untreated retinas and 0.69 ± 0.14 (n = 6 animals) for digoxin-treated retinas. Molecular weight (MW) marker is in kilodaltons. Scale bars, 10 μm.