Inducing Effect of PKA Inhibitor at Different Concentrations on Platelet Apoptosis and Its Mechanism

OBJECTIVE To investigate the inducing effect of PKA inhibitor H89 of different concentrations on platelet apoptosis and its mechanism. METHODS Platelets were isolated from peripheral venous blood of healthy volunteers. Different concentrations gradient PKA inhibitor H89 were co-incubated with washing platelets, and the effects of PKA inhibitor H89 at different concentrations on platelet mitochondrial membrane potential, phosphatidylserine and reactive oxygen species(ROS) were determined by ELISA and flow cytometry. RESULTS Different concentration of PKA inhibitor H89 could induce the depolarization of mitochondrial membrane potential and PS exposure of platelet. However, high concentration(100 μmol/L) PKA inhibitor H89 could induce the production of ROS in platelets, but medium and low concentrations did not induce the production of ROS in platelets. And several ROS inhibitors could inhibit the apoptosis induced by high concentration PKA inhibitor H89. CONCLUSION High concentration H89 can induce platelet apoptosis, however the mechanism of platelet apoptosis caused by H89 of high concentration is different from H89 at medium and low concentrations.