Figure 2.

Effects of TQ-6 on cytotoxicity, lactate dehydrogenase (LDH) release, ATP-release reaction, relative [Ca²⁺]i mobilization, and surface FITC-P-selectin expression in human platelets. (A) Washed platelets (3.6 × 10⁸ cells/ml) were preincubated with the solvent control (0.5% DMSO) or TQ-6 (100 μM) for 10 min, and subsequently washed two times with Tyrode’s solution, followed by the addition of collagen (1 μg/ml) to trigger platelet aggregation. (B) LDH experiment: platelets were preincubated with TQ-6 (20, 50, and 100 µΜ) for 10 min, and a 10-µl aliquot of supernatant was deposited on a Fuji Dri-Chem slide LDH-PIII as described in “Materials and Methods”. Moreover, washed platelets (3.6 × 10⁸ cells/ml) were preincubated with TQ-6 (0.3 and 0.5 µM) or the solvent control (0.5% DMSO), and 1 μg/ml collagen was then added to stimulate either (C) ATP-release reaction (AU; arbitrary unit) or (D) relative [Ca²⁺]i mobilization (ratio 340/380 nm). (E) Washed platelets (3.6 × 10⁸/ml) were preincubated with TQ-6 (0.3 and 0.5 µM) or the solvent control (0.5% DMSO) and FITC-P-selectin (2 µg/ml) for 3 min, and then stimulated by collagen (1 μg/ml). Profiles in (A) are representative of four independent experiments. Data in (B–E) are presented as means ± standard errors of the means (n = 4). *p < 0.05 and **p < 0.01, compared with the resting control; ^#p < 0.05 and ^##p < 0.01, compared with the 0.5% DMSO-treated group.