Changes of asymmetric dimethylarginine,nitric oxide,tetrahydrobiopterin,and oxidative stress in patients with acute myocardial infarction by medical treatments

Abstract

The relationship among the nitric oxide synthase (NOS) inhibitor [asymmetric dimethylarginine (ADMA)], NOS cofactor [tetrahydrobiopterin (BH₄)], and superoxide anion in the patients with acute myocardial infarction (AMI) is still unknown. This study sought to assess the NOS inhibitor and cofactor with oxidative stress in AMI patients (n=9) during initial administration and 4 weeks after medical treatments. We measured plasma NOS inhibitor and cofactor (ADMA and BH₄) by HPLC and plasma oxidized-LDL by ELISA. Blood samples from age-matched healthy volunteers (n=9) were taken for comparison. In AMI, plasma ADMA, oxidized-BH₄ (BH₂+biopterin) and oxidized-LDL significantly increased (P<0.0001, P<0.01 and P<0.05 vs. healthy volunteers) and plasma BH₄, plasma nitrate and L-arginine/ADMA significantly decreased compared with healthy volunteers (P<0.0001, P<0.05 and P<0.005 vs. healthy volunteers). Medical treatments improved plasma ADMA, nitrate, BH₄ and oxidized-LDL. In conclusion, ADMA increased, and NO and BH₄ decreased with oxidative stress in AMI, and these mediators improved in AMI patients with medical treatments. These findings indicated that inhibition of NOS with oxidative stress plays a crucial role in endothelial dysfunction in patients with AMI.