Abstract: The effect and mechanism of glycosaminoglycan from Urechis unicinctus on platelet aggregation in rats were studied.The maximum aggregation percentage of platelets in rats was determined using turbidimetric method,and calcium ion concentration in rat platelets was determined using Fura-2 dual wavelength fluorescence method,and laser scanning confocal microscope was used to detect the level of calcium in rat platelets;Concentrations of rat platelets cAMP,plasma TXB₂, 6-keto prostaglandin F1α and platelet glycoprotein (GPIIb/IIIa) were determined with enzyme linked immunosorbent assay.The results showed that glycosaminoglycan from Urechis unicinctus could significantly reduce maximum aggregation rate in rat platelets (P<0.01),significantly reduce calcium ion concentration in platelets (P<0.01),significantly increase cAMP concentration in rat platelets (P<0.01),significantly decrease the concentration of TXB₂ in plasma (P<0.05),significantly increase 6 keto prostaglandin F1α concentration in rat plasma (P<0.01),and significantly decrease the concentration of platelet glycoprotein (P<0.05).The mechanism of anti-platelet aggregation in rat of glycosaminoglycan from U.unicinctus was preliminarily revealed in this study,which laid a scientific basis for the further utilization of the glycosaminoglycan.

Key words: Urechis unicinctus, glycosaminoglycan, antiplatelet aggregation effect