Fig. 3.

Complement activation by CS in the fluid phase. Platelet-poor plasma (PPP) was incubated with increasing concentrations of chondroitin sulfate (CS) for 30 min at 37 °C, and the generation of C3a (A) and sC5b-9 (B) in PPP (diamonds), without additives and in the presence of 10 mm EDTA (triangles) or 10 mm Mg²⁺-EGTA (squares), was measured by enzyme-linked immunosorbent assay (ELISA). CS (25 μg mL⁻¹) and supernatants from isolated and thrombin receptor-activating peptide-activated platelets (PS) were treated with 5 U of chondroitinase ABC (CSE) for 5 h at 37 °C, and then incubated with PPP for 30 min at 37 °C (white bars). In the same experiments, CS and PS were incubated in PPP in the absence (black bars) or presence (gray bars) of 10 mm Mg²⁺-EGTA. The generation of C3a (C) and sC5b-9 (D) was analyzed by ELISA. Data are mean ± SEM (n = 3). AU, arbitrary units.