Vimentin-ir in SAMR1 and SAMP8 urethras and its co-localization with cGMP-ir. (A–C) Representative confocal images showing z-stacks of a 2 μm section from the proximal SAMR1 urethra treated with DEA/NO (0.1 mM, 4 min). Vimentin-ir (A, red) and cGMP-ir (B, green) are shown along with the corresponding merged image (C). Note the co-localization of vimentin-ir and cGMP-ir in numerous spindle-shaped ICs, in which vimentin-ir is mainly concentrated at the periphery of the cell and in the cell processes in particular, while cGMP-ir predominantly accumulates in the cytosol. Scale bar = 10 μm. (D) Quantification of vimentin-ir in SAMR1 and SAMP8 urethras. Measurements were taken independently in different regions of the urethral muscular layer (proximal, medial and distal). Hand-drawn fields of whole-mount preparations were selected and the relative area above the intensity threshold was measured (Area %). The values represent the mean ± SE of three to five different fields from four to six different animals: *P < 0.05 versus SAMR1 (anova followed by Student's t-test).