Early changes in the Schwann cells in experimental allergic neuritis.
Experimental allergic neuritis (EAN) was induced in guinea-pigs by intradermal injection of rabbit peripheral nerve emulsified in Freund's adjuvant. Both sciatic nerves were obtained between 12--24 hr after clinical symptoms were evident. Several fascicles from each nerve were isolated for histochemical studies with NADH-diaphorase (NADH) and acid phosphatase (AP) applied to teased nerve fibres. Small pieces were processed for electron microscopy, and a fascicle was teased after staining with osmium tetroxide. In isolated nerve fibres stained with histochemical techniques myelin lesions of segmental character were found closely related to inflammatory cells; Schwann cell cytoplasm in contact with mononuclear cells showing a heavy enzymatic activity (NADH and AP). Under polarized light, the underliying myelin showed focal loss of birefringence. Some electron-microscopic pictures suggested active myelin breakdown by mononuclear cells. The possibility of primary Schwann cell damage by mononuclear cells with subsequent demyelination is discussed.
D000135:Acid Phosphatase / Q000378:metabolism; D000818:Animals; D008058:Dihydrolipoamide Dehydrogenase / Q000378:metabolism; D005260:Female; D006168:Guinea Pigs; D006651:Histocytochemistry; D006967:Hypersensitivity / Q000201:enzymology / Q000473:pathology*; D009443:Neuritis / Q000201:enzymology / Q000473:pathology*; D012583:Schwann Cells / Q000201:enzymology / Q000648:ultrastructure*
D008058:Dihydrolipoamide Dehydrogenase; D000135:Acid Phosphatase