Effect of enoxaparin and aspirin on hemodynamic disturbances after global cerebral ischemia in rats.
OBJECTIVE
Whether patients benefit from anticoagulation or anti-platelet agents when subjected to global ischemia is controversial. In this study we assessed the effect of enoxaparin and aspirin on hemodynamic disturbances following global ischemia in rats.


METHODS
Twenty-minute global ischemia was induced by four-vessel occlusion in Sprague-Dawley rats. Enoxaparin (1.5 mg/kg, i.v.) was administered 4 min before or after ischemia, and aspirin (40 mg/kg, i.p.) was administered twice, 18 and 1.5 h before ischemia. Parietal cortical cerebral blood flow was measured in real time with a laser Doppler flowmeter, and activated partial thromboplastin time (APTT) and prothrombin time (PT) were measured. Three phenomena of hemodynamic disturbance: no-reflow, hyperperfusion, and hypoperfusion, were assessed after 20-min global ischemia.


RESULTS
No significant differences in PT values were found; in contrast, the APTT values were shortened markedly by 20-min ischemia, which indicated activation of the endogenous coagulation system. The shortened APTT was markedly prevented by enoxaparin administered before ischemia. 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 min before or after ischemia.


CONCLUSIONS
These results indicate that enoxaparin and aspirin have protective effects against cerebral hemodynamic disturbances induced by global ischemia in rats.
Xu
LuoYi
L
Department of Neurology, the First Affiliated Hospital, Zhejiang University School of Medicine, 89 Qingchun Road, Hangzhou 310003, China.
Wang
JingYe
J
Pan
Jie
J
Sun
LiNa
L
Xia
Qiang
Q
Luo
BenYan
B
D000818:Animals; D000925:Anticoagulants / Q000627:therapeutic use*; D001241:Aspirin / Q000627:therapeutic use*; D002545:Brain Ischemia / Q000097:blood / Q000188:drug therapy / Q000503:physiopathology*; D002560:Cerebrovascular Circulation / Q000187:drug effects*; D017984:Enoxaparin / Q000627:therapeutic use*; D006439:Hemodynamics / Q000187:drug effects; D017078:Laser-Doppler Flowmetry; D008297:Male; D010314:Partial Thromboplastin Time; D010975:Platelet Aggregation Inhibitors / Q000627:therapeutic use*; D011517:Prothrombin Time; D051381:Rats; D017207:Rats, Sprague-Dawley
D000925:Anticoagulants; D017984:Enoxaparin; D010975:Platelet Aggregation Inhibitors; D001241:Aspirin