AIM: To explore the effct of splenic lymphocytes from oral inr mune tolerance rats on NF-KB p65 actMty in glomerular mesangial cells. METHODS: 10 female Wistar rats with 6-8 weeks of age were divided randomly into two groups, 5 rats for each group. The rats of one group were given through intragastric feeding with 2 mL FxlA antigen to induce oral inr mune tolerance, and the rats of the other group only with PBS (as control group). Two weeks later, the rats were sacrficed, and then their spleens were excised and lymphocytes were sey arated routinely for antigerrspecific lymphocytes reaction. The cukure supernatants of splenic lymphocytes from oral immune tolerance rats were prepared. The L-10 level in the super natants was detected by sandwich FLISA. After the cultured mesangial cells were stimulated with high dose of insulin, the culture supernatants of rat's splenic lymphocytes were added to insulin-treated mesangial cells. Twentyfour hours later, the NF KB p65 actMty in mesangial cells was detected by immunohisto-chemical staining and sandwich ELISA. RESULTS: As com- pared with control group, the proWeration reaction of splenic lymphocytes from oralimmune tolerance rats was inhibited obvr ously, and lL-10 level in splenic lymphocyte culture supernatants from the tolerance rats rose markedly (P<0.01). NF-KB p65 actMty induced by insulin in me sangial cells wa s inhibited by cul-ture superatants of splenic lymphocytes from oralimmune toter ance rats (P<0.05). CONCLUSION: NF-KB p65 actMty in mesangial cells may be inhibited by lL-10 secreted by splenic lymphocytes from the oral immune tolerance rats.