Click on image to view larger version.

Figure 3 (A) The effect of L-NAME, inhibitor of nitric oxide synthesis, on MVO₂ at the highest doses of drug in the LVAD group is shown. N^w-nitro-L-arginine methyl ester attenuated the effect of bradykinin, enalaprilat and amlodipine on oxygen consumption. N^w-nitro-L-arginine methyl ester had no effect on decrease in oxygen consumption in response to diltiazem and nitroglycerin. Striped bar = LVAD-HF; solid bar = +L-NAME. #p < 0.05 from control. (B) Effect of succinate on myocardial oxygen consumption. Succinate, NAD-independent substrate of the electron transport chain, increased MVO₂ in both HF and LVAD-HF groups, and this response was not different between the two groups. Amlo = amlodipine; BK = bradykinin; Dilt = diltiazem; Enal = enalaprilat; HF = heart failure; L-NAME = N^w-nitro-L-arginine methyl ester; LVAD = left ventricular assist device; MVO₂ = myocardial oxygen consumption; NTG = nitroglycerin.