Abstract:
The aim of this study was to examine the effects of glycosaminoglycan (GAG) from Urechis unicinctus on the
P2Y1 receptor pathway and expression of related factors in rat platelets. The concentration of calcium ion (Ca2+) in rat
platelets was determined by double wavelength Fura-2 fluorescence spectrophotometry, and the concentrations of
inositol trisphosphate (IP3) and glycoprotein IIb/IIIa (GPIIb/IIIa) in rat platelets were measured using the enzymatic
immunoassay method. The phosphorylation levels of phospholipase C (PLC), phospholipase A2 (PLA2), protein kinase C
(PKC), and p38 mitogen-activated protein kinase (p38MAPK) were also detected by Western blot. It was found that the
GAG from U. unicinctus significantly reduced the Ca2+ and IP3 levels in rat platelets (p<0.05, p<0.01). Moreover,
medium and high concentrations of GAG significantly reduced the concentration of the platelet membrane GPIIb/IIIa in
rats (p<0.05, p<0.01). The phosphorylation levels of PLC, PLA2, PKC and p38MAPK in rat platelets were also inhibited
by GAG and P2Y1 receptor blocker MRS2179 (p<0.05, p<0.01). However, the degree of inhibition of GAG was lower
than that of MRS2179. The results laid a foundation for further utilization of the glycosaminoglycan.
