Treatment with EPO improves the peripheral nerve histology.

<p>Sections of sciatic nerves obtained at day 29 after immunization were stained for CD3<b>⁺</b> T lymphocytes in non-treated (A) and EPO-treated animals (B and C). Scale bar = 50 µm. Immunohistochemistry developed with 3,3′-diaminobenzidine as peroxidase substrate. Insets: Higher magnification of stained T cells showing brown DAB staining in close proximity to blue labelled nuclei. Sections of sciatic nerves obtained at day 29 after immunization were also stained for CD68+ macrophages in non-treated (D) and EPO-treated animals (E and F). Scale bar = 50 µm. Quantitative analysis of d 15 and d 29 revealed the difference in the number of CD3+ T cells (G) and CD68<b>⁺</b> macrophages (H). Brachial plexus from control EAN rats (I and J) and EPO treated EAN rats following the therapeutic paradigm (K) were dissected at day 29 and epoxin embedded. Ultrathin sections (80 nm) were stained with toluol blue and analyzed in an electron microscope. Stars: demyelinated axons, number symbols: axon degeneration, arrowheads: remyelinated axons. In control treated EAN rats the nerves have more demyelinated fibres without remyelination (I) and axon degeneration (J). Remyelinated fibres were more frequent in peripheral nerves from EPO treated animals (K). Bars = 5 µm. Quantitative analysis of the percentage of degenerated (L) and demyelinated (M) axons of the plexus nerve in the different groups. preven: preventive; therap: therapeutic. Asterisks indicate significance (mean ± SEM, * p<0.05; *** p<0.001); student's <i>t</i> test.