Effect Of Anticoagulation And Antiplatelet Aggregation On Hemodynamic Disturbances Induced By Global Cerebral Ischemia/Reperfusion In Rats

【Objectives】Whether patients benefit from anticoagulation or antiplatelet aggregation when subjected to global ischemia associated with accidents is controversial. So, in this study we assessed the effect of anticoagulation and antiplatelet aggregation on hemodynamic disturbances induced by global ischemia.[Methods]Twenty-minute global ischemia was induced by four-vessel occlusion in rats. Enoxaparin (1.5mg/kg, i.v.), a low molecular weight heparin, was administered 4 min before or after 20-min ischemia, and aspirin (40 mg/kg, i.p.) was administered twice,18 h and 1.5 h before 20-min ischemia. Parietal cortical cerebral blood flow was measured in real time with a laser Doppler flowmeter, and coagulation times of APTT and PT were measured.【Results】Three phenomena of hemodynamic disturbance,no-reflow, several minutes of hyperperfusion,and several hours of hypoperfusion, were detected after 20-min global ischemia. No significant differences of PT values were observed, in contrast, the APTT values were shortened markedly by 20-min ischemia, which indicated the activation of endogenous coagulation system. While the shorten of APTT was prevented greatly by enoxaparin administered before ischemia both in nonischemic and ischemic rats.No-reflow was partly mitigated by administration of enoxaparin or aspirin before ischemia.Hypoperfusion was almost fully blocked by aspirin, and the hypoperfusion value was increased and hypoperfusion duration was shortened by enoxaparin administered 4 minutes before or after ischemia.[Conclusion]These results indicated enoxaparin and aspirin have protective effects against cerebral hemodynamic disturbances after global ischemia in rats. So, in the clinic, patients may benefit from routine aspirin administration or from administration of low molecular weight heparin.