Objective: To observe the changes in the activity of platelet glycoprotein (GP) IIb/IIIa receptor following the occurrence of no-reflow after myocardial reperfusion, to explore the measures for clinical management of this condition.
Methods: Nine canine models of no-reflow following myocardial ischemia verified by reperfusion myocardial contrast echocardiography were used in this investigation. The peripheral venous blood (PVB) and sinus venous blood (SVB) were sampled before myocardial reperfusion (after a 3-hour myocardial ischemia) and after a 3-hour reperfusion for determinating GP IIb/IIIa receptor activities by means of enzyme-linked immunosorbent assay (ELISA).
Results: The activity of platelet GP IIb/IIIa of PVB, either in 3-hour ischemic group or in 3-hour reperfusion group, was elevated significantly (P < 0.001), suggesting platelet activation. Elevated platelet GP IIb/IIIa receptor activity in SVB occurred only in 3-hour ischemic group, and the 3-hour reperfusion group (P < 0.001) and the no-reflow group had significantly decreased activities, which was more obvious in the latter group (P < 0.01). The findings signified the consumption of the platelet GP IIb/IIIa receptors in the myocardial microcirculation and the presence of platelet aggregation.
Conclusions: Myocardial ischemia may activate the platelets to express GP IIb/IIIa receptors through stress response mechanism and damage the endothelia of the microvasculature to incur adhesion and aggregation of the platelets within the microcirculation, which may be one of the pathogeneses for myocardial no-reflow phenomenon.