Treatment of experimental allergic encephalomyelitis with an inhibitor of cathepsin D (pepstatin).

Intraperitoneal administration of pepstatin (2 mg/day for 5 weeks) to Lewis rats subjected to experimental allergic encephalomyelitis (EAE) (induced by guinea pig spinal cord and pertussis vaccine) suppressed the appearance of clinical signs of disease, and reduced the severity and incidence of CNS lesions normally associated with this disease. Administration of pepstatin for shorter periods to Lewis rats, or BSVS mice, or guinea pigs challenged with myelin basic protein delayed, but did not prevent clinical signs of EAE, but was accompanied in all cases by a less severe histopathology.