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

Table 1

Effects of TMP, losartan, and vitamin E on H₂O₂-provoked endothelial dysfunction in isolated rat aortic rings.

Treatment	pD2	(%)
Control	7.20 ± 0.12	6.97 ± 3.32	4
H2O2 (200 M)	6.40 ± 0.23*	57.86 ± 8.24*	6
TMP (100 M) + H2O2	7.05 ± 0.22^#	16.59 ± 9.15^#	5
TMP (1 M) + H2O2	7.29 ± 0.17^#	23.31 ± 9.69^#	5
TMP (10 nM) + H2O2	7.07 ± 0.15^#	30.38 ± 11.25	5
Losartan (1 M) + H2O2	7.02 ± 0.17^#	28.36 ± 8.15^#	5
Vitamin E (100 M) + H2O2	6.94 ± 0.37	57.23 ± 11.97	5

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