Attenuation of experimental autoimmune encephalomyelitis by Compound 48/80 in Lewis rats.

The appearance of increased levels of histamine in the central nervous system (CNS) concomitant with the development of clinically significant acute experimental autoimmune encephalomyelitis (EAE) in male Lewis rats suggests that CNS-associated mast cells may mediate acute EAE in Lewis rats. We now report that, compared to controls, rats with acute EAE exhibit fewer detectable mast cells in their dura mater and velum interpositum. In addition, intracisternal, but not intraperitoneal administration of Compound 48/80 just prior to the appearance of clinical signs of acute or recurrent EAE in male and female rats, respectively, significantly attenuates the clinical severity of both forms of EAE. These results further support the hypothesis that CNS-associated, but not peripheral mast cells are mediators or modulators of acute and recurrent EAE in Lewis rats.