Computer-assisted analysis of regenerating rabbit retinal pigment epithelium

Abstract

While examining thin sections of regenerating rabbit retinal pigment epithelium (RPE) we observed profound changes in ultrastructure as the cells matured. To assist in studying this problem serial thick sections (0.25 μm) through regenerating RPE cells were studied by highvoltage electron microscopy (HVEM) and a computer program (STERECON) used to generate stereo reconstructions.Tissue was obtained from rabbits that received sodium iodate iv -- which destroys large expanses of RPE and permits examination of regeneration from surviving cells. One-two weeks after iodate administration the rabbits were euthanized, the eyes removed and tissue processed for transmission electron microscopy by routine procedures. Serial sections 0.25 μm thick were mounted on Formvar coated slot grids, stained with uranyl acetate and lead citrate and examined with an AEI EM7 1.2 MV HVEM at 1000 kV. Figure 1 illustrates observations made on six sections through the cell seen in Fig. 2. The cell was photographed at 5000x and printed as a montage at 15,000x.