Changes in Plasma Membrane Viscosity and Hemoporphyrin Conformation in Erythrocyte Hemoglobin under the Conditions of Ischemia and Reperfusion of Rat Brain

Abstract

Hypoxia of various origin and localization is accompanied by changes in some physical and chemical properties of erythrocytes: deformability, plasma membrane viscosity, and the oxygen-binding capacity of hemoglobin [1, 4‐6]. Under the conditions of brain ischemia, these properties are studied insufficiently. After postischemic reperfusion (PIR) that restores blood circulation, the oxygen partial pressure in plasma increases, which may stimulate the generation of reactive oxygen species (ROS) and affect the erythrocyte functions. In blood plasma, Cu,Zn-superoxide dismutase (SOD) and ceruloplasmin (CP) are involved in utilization of superoxide anion radical ( ) that triggers ROS formation. In this study, changes in the viscosity of erythrocyte plasma membrane and the e 2 -binding ability of hemoporphyrin of deoxyhemoglobin were studied. SOD activity and CP level were also measured in blood plasma of rats with brain ischemia before and after brain PIR. White outbred male rats weighing 272 ± 11 g were used in experiments. The animals were divided into three groups: the sham-operated rats (the control) ( n = 10), the rats with brain ischemia ( n = 10), and the rats with postischemic brain reperfusion ( n = 7). One day before the experiment, both carotids of the anesthetized animals were underpinned with a fishing line (0.3 mm) that was later withdrawn under skin through the polyethylene tubes into the interscapular region. After one day, a one-stage complete occlusion of both carotids was induced by carotid retraction into the tubes by means of the fishing line; subsequent release of carotids led to PIR. Blood samples (3 ml of blood mixed with heparin, 10 U/ml) were taken from the jugular veins of