Platelets apoptosis in rats after global brain ischemia
Aim. Stroke is one of the most common causes of disability and mortality worldwide. Multiple experimental models of stroke have focused on monitoring of platelet apoptosis. However, studies on and detection of platelet apoptosis in rats with ischemic stroke are very scarce. We investigated platelet apoptosis in rats with global brain ischemia using flow cytometry. Methods. Experiments were carried out on healthy, adult Wistar male rats weighing 300-350 g. The rats were divided into the following 2 groups: intact rats and rats with global brain ischemia. Global brain ischemia was induced by two-vessel (2-VO) carotid occlusion in combination with hypotension. Systemic blood pressure was reduced by 40-45 mm Hg by inducing haemorrhage. Platelets were isolated by gel filtration on Sepharose 2B. For evaluation of phosphatidylserine (PS) externalization, platelets were incubated with Annexin V-PE and analyzed on FACSCalibur (BD Biosciences). Mitochondrial membrane potential (DY) was measured during platelets apoptosis using JC-1, a mitochondrial membrane potential indicator. Platelets were analyzed by flow cytometry immediately after the incubation. Results. PS externalization on platelets was significantly greater after global brain ischemia (53.45 ± 4.21%) than in the control group (5.27 ± 2.40%). Pronounced depolarization of mitochondrial membrane potential (DYm) confirmed this finding. In the rat group with experimental brain ischemia, almost 40% (35.24 ± 5.21%) of platelets were depolarized. Conclusion. Our results provide insight into mechanisms involved in platelet apoptosis during ischemic stroke and can be used in further development of new therapeutic strategies.