To explore whetber The immune response of the inner ear could induce heat shock protein 70 (hsp70) in tile guinea pig cochlea, we established a model of autoimmune inner eat" disease (AIED) by systemically immunizing guinea pigs with homologous crude inner ear antigen (CIEAg).The immunized cochleas and normal control cochleas were examined for the expression of hsp70 by immunohistochemical analysis and in situ hybridization. It was found that 10 of 28 ears showed significant increases in hearing thresholds after the animals had been sensitized with CIEAg, and 67.9% of the ears from the immunized animals had modiolar vasculitis. The hsp70-1ike proteins were basically expressed in the normal cochleas, but dramatically increased expressions of hsp70 (perhaps also including hsp70-1ike molecules) and its messenger RNA were observed in the cochleas of the AIED models. The restltS suggest that the immune response of the inner ear induced the expression of hsp70 in The guinea pig cochleas.