FIGURE 9.
(A–C) Electron micrographs made using fast conventional fixation and silver enhancement show the distribution of 11-nm particles in permeabilized ventricular myocytes. Representative micrographs show the distribution of the nanoparticles before (A) and after (B and C) partial ablation of the cytoskeleton (20 min pretreatment with 40 μM cytochalasin D). (D) Graphs representing the density of nanoparticles (3–21 nm) in intact ventricular cells before (gray) and after (dark gray, only for particles ≥11 nm) 20 min of pretreatment with 40 μM cytochalasin D (n = 26–308). Asterisks indicate data that are statistically different from the corresponding control (P < 0.001). M, mitochondrion; Z, Z line. Arrows indicate T-tubules and blue ovals show nanoparticles located deeper inside the ultrathin section, which therefore have smaller diameters after silver enhancement.