Increased generation of superoxide in erythrocytes infected with Babesia gibsoni

The present study was conducted to clarify the mechanism underlying the oxi dative process in erythrocytes infected with Babesia gibsoni. The parasite B. gibsoni was cultured together with erythrocytes from normal dogs for 7 d ays. When parasitemia reached 12.0-13.4% at Day 7, the production of supero xide in erythrocytes was significantly higher in the parasitized culture th an in the control culture (p < 0.005). The concentration of thiobarbituric acid reactive substances (TBARS) in erythrocytes in parasitized culture was also significantly increased compared with the control culture (p < 0.005) . indicating that lipid peroxidation was greater in infected erythrocytes t han in non-infected cells. In addition, the rates of superoxide generation in the blood of B. gibsoni-infected dogs were also significantly higher tha n in non-infected dogs (p < 0.001). These results indicate that superoxide anions are increased in erythrocytes parasitized with B. gibsoni. and sugge st that oxidative damage, due to lipid peroxidation, might be caused in hos t erythrocytes by the parasite.