FIGURE 4.

Effects of acute exposure to 1.0 mM tBHP on membrane protein was investigated by SDS polyacrylamide gel electrophoresis. 1, control untreated erythrocytes; 2, erythrocytes treated with tBHP (1.0 mM); 3, erythrocytes pretreated with 0.1 μM verapamil before exposure to tBHP (1.0 mM); 4, erythrocytes pretreated with 1.0 μM verapamil before exposure to tBHP (1.0 mM). Treatment with 1.0 mM tBHP caused degradation of membrane protein corresponding to spectrin (band 1, 2), band 3, band 4.2 and band 4.5 associated with the new appearance of the low-molecular-weight broadband as indicated by N. Degradation of band 3 known as membrane protein exchanging anions (Cl^– and HCO₃^–) and regulating cellular volume may contribute to tBHP-induced erythrocyte swelling. Although verapamil is a possible antioxidative agent, pretreatment with verapamil did not show any apparent protective effects [cited from Okamoto et al. (2004) with permission].