Effects of thermal trauma on dog erythrocyte ATPase and shape

Studies have been carried out on dog erythrocytes to determine the effects of heating to 57 degrees C on membrane ATPase and erythrocyte shape. The results of these studies showed that after heating the blood there was approximately a 30 per cent decrease in membrane ATPase and an alteration of erythrocyte shape from biconcave to spherical. Additional studies of the effects of addition of arachidonic acid to erythrocyte-membrane homogenates demonstrated that this substance produced a dose-related inhibition of ATPase. If the additions were made to membranes from blood which had previously been heated, the effects of arachidonic acid and heat were additive. Addition of the hydroxyl-radical scavenger catalase to the blood before heating prevented the observed decrease in ATPase and prevented the change in shape to spherical. These results confirm the previous findings of Bessis that heat will cause a change in the erythrocyte shape from biconcave to spherical and suggest that the mechanism responsible for this change is an alteration in membrane ATPase. The observation that a similar response can be produced by arachidonic acid suggests that metabolism of this substance may generate agents which are capable of inhibiting erythrocyte membrane ATPase. The observation that catalase will prevent the ATPase inhibition and the change in erythrocyte shape suggests that hydroxyl-free radicals play an important part in this thermal trauma-induced response.