Effects and mechanisms of triacetylshikimic acid on platelet adhesion to neutrophils induced by thrombin and reperfusion after focal cerebral ischemia in rats

AIM: To investigate the effect of triacetylshikimic acid (TSA) on the plate let adhesion to neutrophils and P-selectin expression on activated platelet membrane induced by thrombin and reperfusion after focal cerebral ischemia . METHODS: The platelet adhesion to neutrophils was evaluated by rosette as say, and P-selectin expression on platelet membrane was determined by flow cytometry. RESULTS: TSA 10 - 1000 mu mol/L markedly inhibited thrombin(0.4 kU/L)-induced platelet adhesion to neutrophils. The platelet adhesion to ne utrophils induced by a 21-h reperfusion after middle cerebral artery occlus ion for 3 h was also inhibited in a dose-dependent manner by TSA 50 - 200 m g/kg given by ig immediately and at 60 min again after the onset of cerebra l ischemia. TSA was also shown to decrease the P-selectin expression on pla telet surface induced by thrombin in washed platelet and by adenosine dipho sphate (ADP) 5 mu mol/L in whole blood. CONCLUSION: Reperfusion after cereb ral ischemia and thrombin induced platelet adhesion to neutrophils, which c ould be reduced by TSA probably due to its inhibition of P-selectin express ion on activated platelets.