Study On Anticoagulant Mechanism Of Glycosaminoglycan From Mactra Veneriformis

Mactra veneriformis belongs to Mollusca, Lamellibranchia,Clams Branch.It has rich protein,unsaturated fatty acids, polysaccharides,vitamins and trace elements. Traditional Chinese medicine theory think that the clam is cold, salty taste,nourishing yin,diuresis,phlegm,soften hardness.It has some functions,such as diabetes,edema, sputum volume. Previous research had shown that glycosaminoglycan from Mactra veneriformis had good anticoagulant effect. However, the anticoagulant mechanism of glycosaminoglycan from Mactra veneriformis is not very clear. In the thesis, the anticoagulant mechanism of glycosaminoglycan from Mactra veneriformis will have been revealed through studying the dependence of anticoagulation activity of glycosaminoglycan on AT-Ⅲ, HC-Ⅱ, and the effect of glycosaminoglycan on several clotting factors and protein C system.The dependence of anticoagulation activity of glycosaminoglycan on AT-Ⅲ, HC-Ⅱ was studied by PT, TT method. It showed that the glycosaminoglycan mainly exerted anticoagulant effect by AT-Ⅲ, other factors might play a rol.When the heparin cofactor II combines the glycosaminoglycan from Mactra veneriformis, the activated of heparin cofactor II might be wekened.The activities of coagulation cofactors Ⅱ、Ⅴ、Ⅶ、Ⅹ、Ⅷ、Ⅸ、Ⅺ、Ⅻ were determined by correcting lack of factor plasma causes extension of coagulation time. The content of fibrinogen was measured using fibrinogen kit.The results showed that the high concentration of glycosaminoglycan could significantly reduce the content of plasma fibrinogen (P<0.05,P<0.01), and low concentration of glycosaminoglycan could reduce the content of plasma fibrinogen, but it was not significantly. Glycosaminoglycan could significantly reduce the activities of Ⅱ、Ⅴ、Ⅶ、Ⅹ、Ⅷ、 Ⅸ、Ⅺ、Ⅻ (P<0.05, P<0.01).The ability that glycosaminoglycan reduced the activities of Ⅸ、Ⅺ、Ⅻ was significantly lower than heparin (P<0.01), and the ability that glycosaminoglycan reduced the activities of Ⅱ、Ⅴ、Ⅶ、Ⅹ、Ⅷ was lower obviously than heparin. But the ability that glycosaminoglycan reduced the activity of Ⅹ was slightly higher than that of heparin. So the anticoagulant ability of heparin was higher than that of glycosaminoglycan.The impact of glycosaminoglycan on recalcification time in rats was studied using the recalcification experiment in vitro, and the calcium ion concentration in mice, rats blood was determined by methyl thymol blue method.The results showed that glycosaminoglycan could lengthen recalcification and coagulation time in rats by shielding the blood Ca2+, and significantly reduce calcium concentration in rats and mice serum, and the strength reducing calcium concentration of blood was stronger significantly than heparin(P<0.05, P<0.01).The effect of glycosaminoglycan on PC, PS, APCI, TM of protein C system using enzyme linked immunosorbent assays method.The results showed that glycosaminoglycan could decreased the concentration of activitied PC, PS and TM, and significantly decreased the concentration of activitied PC, PS in the middle and high concentration glycosaminoglycan groups (P<0.05, P<0.01), and glycosaminoglycan slightly increased the concentration of activitied APCI.