Treatment of experimental allergic neuritis with nedocromil sodium.

Peripheral nervous system mast cells degranulate early in the development of experimental allergic neuritis (EAN). This degranulation is associated with the release of vasoactive amines, chemoattractants and myelinolytic proteases which could provide a focus for inflammatory demyelination. To further assess the importance of mast cell degranulation in the development of EAN, we have treated Lewis rats inoculated with peripheral nervous system myelin and complete Freund's adjuvant, with nedocromil sodium, an anti-inflammatory drug with mast cell stabilizing properties. Treatment with nedocromil sodium (100-150 mg/kg), 3 times daily, starting on day 7 post-inoculation, significantly decreases the incidence and the severity of the disease. Histological examination of sciatic nerves confirms the absence of subclinical disease in successfully treated animals. The possible mode of action of the drug is discussed.