Effects and mechanisms of triacetylshikimic acid on platelet adhesion to neutrophils induced by thrombin and reperfusion after focal cerebral ischemia in rats
Abstract
Aim: To investigate the effect of triacetylshikimic acid (TSA) on the platelet 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 assay, and P-selectin expression on platelet membrane was determined by flow cytometry.
Results: TSA 10 - 1000 micromol/L markedly inhibited thrombin(0.4 kU/L)-induced platelet adhesion to neutrophils. The platelet adhesion to neutrophils induced by a 21-h reperfusion after middle cerebral artery occlusion for 3 h was also inhibited in a dose-dependent manner by TSA 50 - 200 mg/kg given by ig immediately and at 60 min again after the onset of cerebral ischemia. TSA was also shown to decrease the P-selectin expression on platelet surface induced by thrombin in washed platelet and by adenosine diphosphate (ADP) 5 micromol/L in whole blood.
Conclusion: Reperfusion after cerebral ischemia and thrombin induced platelet adhesion to neutrophils, which could be reduced by TSA probably due to its inhibition of P-selectin expression on activated platelets.
Keywords:
Methods: The platelet adhesion to neutrophils was evaluated by rosette assay, and P-selectin expression on platelet membrane was determined by flow cytometry.
Results: TSA 10 - 1000 micromol/L markedly inhibited thrombin(0.4 kU/L)-induced platelet adhesion to neutrophils. The platelet adhesion to neutrophils induced by a 21-h reperfusion after middle cerebral artery occlusion for 3 h was also inhibited in a dose-dependent manner by TSA 50 - 200 mg/kg given by ig immediately and at 60 min again after the onset of cerebral ischemia. TSA was also shown to decrease the P-selectin expression on platelet surface induced by thrombin in washed platelet and by adenosine diphosphate (ADP) 5 micromol/L in whole blood.
Conclusion: Reperfusion after cerebral ischemia and thrombin induced platelet adhesion to neutrophils, which could be reduced by TSA probably due to its inhibition of P-selectin expression on activated platelets.