Effects of glycosaminoglycan from Mactra veneriformis on the protein C system and expression of relevant factors in human umbilical vein endothelial cells.

The aim of this study was to examine whether glycosaminoglycan (GAG) from Mactra veneriformis had an impact on the protein C (PC) system in rats and expression of relevant factors in human umbilical vein endothelial cells. Isotonic saline, heparin sodium (4 mg/kg), and GAG (1, 4, and 16 mg/kg) were administered to Wistar rats through caudal vein at the total volume of 0.5 ml for each injection, and the anticoagulant blood was prepared. The activities of PC and protein S, and the concentrations of activated protein C inhibitor (APCI) and thrombomodulin were detected according to the kit instructions. The expression levels of tissue factor, tissue factor pathway inhibitor and thrombomodulin genes in human umbilical vein endothelial cells were detected by the reverse transcription polymerase chain reaction method. GAG could significantly reduce the activity of PC (P < 0.05, P < 0.01) and slightly increase the concentration of APCI, and high concentration of GAG could significantly decrease the activity of protein S (P < 0.05) and significantly increase the concentration of thrombomodulin (P < 0.05). GAG could significantly downregulate the expression level of tissue factor gene (P < 0.05, P < 0.01) and significantly upregulate the expression levels of tissue factor pathway inhibitor and thrombomodulin genes (P < 0.05, P < 0.01). GAG showed the inhibitory effect on PC system in vivo. GAG might play an important role in the resistance to extrinsic coagulation pathway.