PLATELET ACTIVATION AND ERYTHROCYTE AGGREGATION RATE IN PATIENTS WITHCEREBRAL INFARCTION

We measured the platelet activation and the rate of erythrocyte aggreg ation simultaneously employing venous blood from 31 patients with cere bral infarction during the acute phase (less than 7 days after onset) and 73 patients with cerebral infarction during the chronic phase (mor e than 1 month after onset.). The degree of platelet activation was es timated from the levels of plasma beta-thromboglobulin (BTG), platelet factor 4 (PF4), and thrombospondin (TSP). The erythrocyte aggregation rate was examined using the whole-blood erythrocyte aggregometer deve loped by us (Am. J. Physiol. 251, H1205-H1210, 1986) with concomitant measurement of the fibrinogen concentration. The mean values of the er ythrocyte aggregation rate, plasma BTG, PF4, TSP and fibrinogen concen tration at the acute phase of cerebral infarction were statistically s ignificantly (P<0.05) higher than those at the chronic phase of cerebr al infarction or in the control group, Multiple regression analysis re vealed that fibrinogen, BTG and TSP were main factors contributing to the enhanced erythrocyte aggregation rate at the acute phase of cerebr al infarction, but fibrinogen was the sole contributing factor at the chronic phase of cerebral infarction. We conclude that the platelet ac tivation, erythrocyte aggregation rate and fibrinogen concentration we re closely correlated with each other in patients with cerebral infarc tion during the acute phase.