Kasatkina L. Exocytosis and glutamate transport by high-affinity Na+-dependent transporters in platelets

Object: exocytosis and active glutamate transport in platelets. Aim: to investigate biochemical mechanisms of regulation of active glutamate transport and exocytosis in platelets. Methods: preparative biochemistry, spectrofluorimetry, flow cytometry, confocal laser scanning microscopy, photon correlation spectroscopy, spectrophotometry, methods of statistical analysis. It was shown that depolarization of the platelet plasma membrane caused a decrease in the initial velocity of high-affinity Na+-dependent glutamate uptake. In contrast to isolated brain nerve terminals, unstimulated and transporter-mediated glutamate release were not registered in platelets. It was shown that degranulation during platelet activation is the only way of glutamate release from platelets. A decrease in membrane cholesterol content evoked dissipation of proton gradient of platelet secretory granules and attenuated glutamate accumulation.