Figure 2.

Effect of 7-ketocholesterol on ADP-mediated relaxation of rabbit aorta. Graph A shows concentration-response curves to ADP of arteries precontracted with 0.3 μM NE in the presence or in the absence of LNA (0.01 mM) and preincubated for 2 h without (control) or with (7-keto) 90 μg ml⁻¹ of 7-ketocholesterol. Concentration-response curves obtained in the absence of LNA represent the total relaxing response (endothelium-independent plus endothelium-dependent relaxation) of arteries to ADP whereas those obtained in the presence of LNA represent exclusively the endothelium-independent relaxation induced by ADP. Graph B shows calculated endothelium-dependent relaxing response to ADP resulting from the difference between the total relaxation (A-squares) and the endothelium-independent relaxation (A-triangles). Data in Graph B are expressed as delta of % Relaxation. Each point represents the mean±s.e.mean of six distinct experiments. Significantly different from control: ^aP<0.05, ^bP<0.01.