Abstract: Abstract Objective: To investigate the possible mechanism of platelet-derived microparticles (PMPs) effecting on vascular endothelial growth factor（VEGF）releasing and its clinical significance in endothelial cells.Methods: Human umbilical vein endothelial cells (HUVECs) CRL-1730 were commonly cultured. Different concentrations of PMPs intervene HUVECs and incubate for different time. We used semi-quantitative reverse transcription polymerase chain reaction techniques to measure VEGF、phosphatidylinositol-3 kinase(PI3K)、extracellular signal-regulated kinase(ERK)and VEGF type II receptor (KDR) mRNA levels. Results: (1)VEGF mRNA level in 0 mg/L group was significantly higher than the 10、30、50、100 PMPs mg/L groups(P<0.05,respectively).In contrast, Flt/KDR mRNA mRNA level in 0 mg/L group was significantly lower than the 10、30、50、100 mg/L PMPs groups(P<0.05,respectively).ERK mRNA level(1.141±0.093) in 50 mg/L PMPs group was significantly higher than that of the 0 mg/L group(0.749±0.205）,P=0.004.PI3K mRNA level(1.344±0.133) in 100mg/L PMPs group was significantly higher than that of the 0 mg/L group(0.999±0.246),P=0.004.(2)Just as the effect of different concentration PMPs on mRNA expression, VEGF mRNA level(0.746±0.179) in 0 hours group was significantly higher than that of the 24 hours intervention group(0.318 ±0.091),P＜0.001.KDR mRNA level in 0 hours group was significantly lower than the 4hours and 24hours groups (P<0.05, respectively).PI3K mRNA level(0.999±0.246) in 0 hours group was significantly lower than that of the 24hours group (2.622±1.213),P=0.004)..Conclusions: PMPs may induce the biological processes of blood vessel and angiogenesis via VEGF receptor and its downstream signal transduction pathways.

Key words: Platelet Activation, Endothelial Cells, Vascular Endothelial Growth Factors 1-Phosphatidylinositol 3-Kinase, Extracellular Signal-Regulated MAP Kinases, Signal Transduction