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Updated: Sep 15, 2026
Platelet Adhesion and Aggregation Under Flow using Microfluidic Flow Cells
Published on: October 27, 2009
Inhibitory effects of sodium quercetin monosulfate on pig platelet aggregation induced by thrombin
1Institute of Medical Biochemistry, Guangdong Medical College, Zhanjiang, China.
Aim:
To study the inhibitory effects of sodium quercetin monosulfate (SQMS) on pig platelet aggregation induced by thrombin.
Methods:
Platelet aggregation was analyzed by turbidimetry. Cytosolic free calcium concentration ([Ca2+]i) was determined by Fura-2 fluorescence. Activity of protein kinase C (PKC) was assayed by incubating PKC with histone III S and [gamma-32 P] ATP. The cytoskeletal proteins were precipitated by Triton X-100 and separated by SDS-PAGE.
Results:
SQMS inhibited the platelet aggregation induced by thrombin 500 U.L-1 with IC50 132 (50-347) mumol.L-1. SQMS inhibited Ca2+ influx in blood platelets induced by thrombin 500 U.L-1 in the presence of extracellular Ca2+ 1 mmol.L-1 with IC50 20 (9-46) mumol.L-1; SQMS inhibited the internal Ca2+ release in the absence of extracellular Ca2+. SQMS also decreased [Ca2+]i level in quiescent blood platelets. SQMS (10-160 mumol.L-1) inhibited the activity of cytosolic PKC from blood platelets in a concentration-dependent manner, but had no effect on membrane PKC. SQMS (20-80 mumol.L-1) inhibited the actin polymerization induced by thrombin 500 U.L-1 inblood platelets in a concentration-dependent manner.
Conclusion:
SQMS inhibited pig platelet aggregation induced by thrombin and its mechanism might be due to its inhibitions of Ca2+ influx, internal Ca2- release, PKC activity, and actin polymerization.
