Figure 2.

Effects of catalase (1000 U ml⁻¹), superoxide dismutase (SOD, 150 U ml⁻¹), and dimethylsulphoxide (DMSO, 5 mM), on the biphasic response to H₂O₂ (10^–3 M) in PHE-precontracted MA of SHR (without TP receptor antagonist). Endothelium was removed in all the arteries. Contraction (upward bars) and the following relaxation response (downward bars) were expressed as a percentage of PHE-precontraction. Results (mean±s.e.) were from four to six rats. Catalase almost eliminated the H₂O₂ response, while SOD or DMSO had no effects. ^**P<0.01 compared with control.