Fig. 7.

Effect of the NADPH oxidase inhibitor apocynin on bradykinin-mediated dilation of arterioles. Apocynin did not significantly alter bradykinin-mediated dilation in nonoccluded (A) or collateral-dependent (B) arterioles of sedentary pigs. Apocynin significantly attenuated dilation in nonoccluded (C) and collateral-dependent (D) arterioles of exercise-trained pigs. In the presence of apocynin, IC₅₀ values revealed that sensitivity to bradykinin was not altered in arterioles from the nonoccluded and collateral-dependent regions of sedentary pigs (A and B, insets). Apocynin significantly reduced sensitivity to bradykinin in arterioles from the nonoccluded and collateral-dependent regions of exercise-trained pigs (C and D, insets). Values are means ± SE of number of animals in parentheses. *P ≤ 0.05.