Tetramethylpyrazine Protects against Hydrogen Peroxide-Provoked Endothelial Dysfunction in Isolated Rat Aortic Rings: Implications for Antioxidant Therapy of Vascular Diseases

Table 2

Effects of catalase, apocynin, and DPI on H₂O₂-provoked endothelial dysfunction in isolated rat aortic rings.

Treatment	pD2	(%)
Control	7.22 ± 0.07	5.32 ± 2.93	4
H2O2 (200 M)	4.63 ± 0.25*	59.88 ± 6.44*	6
Catalase (20000 U/mL) + H2O2	6.10 ± 0.07^#	26.11 ± 6.34^#	4
Apocynin (10 M) + H2O2	6.51 ± 0.13^#	27.31 ± 10.51^#	4
DPI (10 nM) + H2O2	6.33 ± 0.09^#	16.88 ± 8.82^#	4

Data represent the mean ± the SEM of 4–6 independent experiments ( versus control; versus H₂O₂).
DPI: diphenyleneiodonium; : maximal response; H₂O₂: hydrogen peroxide; pD₂: negative logarithm of the EC₅₀; SEM: standard error of the mean.