EVIDENCE OF FREE-RADICAL DAMAGE IN THE CENTRAL-NERVOUS-SYSTEM OF GUINEA-PIGS AT THE PROLONGED ACUTE AND EARLY RELAPSE STAGES OF CHRONIC RELAPSING EXPERIMENTAL ALLERGIC ENCEPHALOMYELITIS

Central nervous system tissue from guinea-pigs in various stages of ch ronic relapsing experimental allergic encephalomyelitis (CR-EAE) has b een analysed for evidence of free radical damage using the thiobarbitu ric acid test as an indicator of oxidative changes. Levels of thiobarb ituric acid-reactive materials in brain and spinal cord regions from p rolonged acute and early relapse phases of CR-EAE were significantly h igher than in central nervous system tissue from Freund's adjuvant con trol and normal uninoculated animals. In the late relapse phase of CR- EAE, levels of thiobarbituric acid-reactive materials in CNS samples w ere at control values. Fluorescence analysis of central nervous system tissue confirmed evidence of increased free radical damage in prolong ed acute and early relapse stages of CR-EAE. The increased oxidative d amage observed in the central nervous system in CR-EAE is discussed in relation to the role of macrophages and their oxidative burst.