FIGURE 4.

Accumulation of amorphous electron-dense material and formation of membrane-bound granular inclusions in proximity of triads and mitochondria of MCK-βAPP muscle fibers. Electron-dense bodies of granular electron-dense material were found in MCK-βAPP muscle fibers, often in proximity of triads and mitochondria. Arrows mark the central elements of triads, the T-tubule, whereas the star in A points to an accumulation of electron-dense material, which is not yet as dense and not enclosed in a membrane as those indicated by arrowheads in B and C. Bar, A–C, 0.2 μm.