Systemic administration of histamine reduces reovirus type 2-induced insulitis in suckling DBA/1 mice

Previously we suggested that reovirus type 2 (Reo-2) infection induced autoimmune insulitis, resulting in mild diabetes in suckling mice. The effect of histamine (a lymphocyte function suppressor) on Reo-2-induced insulitis was examined. Systemic histamine administration reduced the development of insulitis and blood glucose elevation. Endogenous interleukin-2 (IL-2) activity by splenic cells and the production of antibodies to pancreatic islet cells were reduced by histamine treatment. In addition, histamine treatment increased cyclic adenosine monophosphate (cAMP) concentrations in the plasma. These results further suggest that the insulitis seen in Reo-2 infection in suckling mice is induced by an immune reaction.