Erythrocyte Deformability in Patients with Cerebrovascular Accidents

Recently, erythrocyte deformability has been observed as one of many factors relating to microcirculation. We have improved on the Reid's filtration technique for the determination of erythrocyte deformability, and measured erythrocyte deformabilities in patients with cerebrovascular accidents (C. V. A.) by this method, as well as erythrocyte 2, 3-DPG and ATP concentrations.Heparinized venous blood was immediately washed once with triethanolamine HCl buffer (pH 7.40, 294mOsm/1)at 0 to 4°C, and made into a hematocrit 40% red cell suspension in the same buffer. Then, erythrocyte deformability was measured after the 30 minutes incubation at 37°C.With reference to aging, there was no significant difference in the deformability index (D. I.) among non-smoking normal subjects. D. I. levels in normal subjects (mean=67.9ys. o.), patients with cerebral thrombosis (m.=64.3ys. o.) and patients with cerebral hemorrhage (m.=69.4ys. o.) were 0.80±0.07, 0.57±0.06 and 0.48±0.06ml⋅RBC/min., respectively. There was statistically a definite difference between normal and C. V. A. groups. A marked reduction in D. I. was observed among patients who suffered from an attack of cerebral thrombosis within one month, but after that the reduced D. I. was improved gradually.On the other hand, there was no difference in erythrocyte 2, 3-DPG levels among C. V. A., but there was a marked increment of erythrocyte ATP contents. Generally it is known that a reduction in erythrocyte ATP induced erythrocyte deformability. Therefore, as our results the mechanism of reduced D. I. in C. V. A. is obscure.These above observations suggest that a reduction of D. I. might be one of the most important factors in the cause of C. V. A. and also develops tissue anoxia.