Effects of prednisone on experimental allergic encephalomyelitis rats

Objective To investigate the effects of prednisone(PRD) on experimental allergic encephalomyelitis(EAE) and the mechanism.Methods Lewis rats were injected with mixture of guinea pig spinal extracts and Freund's adjuvant(FA) to induce EAE.PRD(5 mg/kg) was orally given ten days after the injection.The clinical manifestation of rats,their peripheral blood lymphocytes CD3~(+),CD4~(+),CD8~(+) and NK subsets,and pathology changes of brain and spinal were studied on day 26.Results In model CD3~(+) ratio is 63.2%,CD4~(+)ratio 46.8%,CD8~(+)ratio 17.4% and NK ratio 10.2%.In PRD CD3~(+) ratio is 69.5%,CD4~(+)ratio 51.8%,CD8~(+)ratio 18.1% and NK ratio 5.3%.PRD obviously decreased the clinical scores of EAE rats and peripheral blood NK ratio,increased CD3~(+) and CD4~(+)ratio,inhibited brain inflammatory reaction and demyelination.However,PRD didn't affect peripheral blood lymphocytes CD8~(+) and CD4~(+)/CD8~(+)ratio.Conclusions PRD is effective in the treatment of EAE rats,and the therapeutic mechanism may be contributed to the decrease of the peripheral blood NK ratio and increase CD3~(+) and CD4~(+)ratio.