Fall in antioxidant reserve (AR) in coronary sinus blood following angioplasty

Since coronary angioptasty is associated with acute ischemia during angioplasty and reperfusion thereafter, it is probable that is causes the formation of increased amounts of reactive oxygen species (ROS). We, therefore, measured ROS generation by mononuclcar cells (MNC) prepared from sequential coronary sinus (CS) blood samples obtained from an indwelling catheter (0 minutes, during, 3, 20, and 60 minutes after angioplasty and also antioxidant reserve in the same samples. ROS generation was assayed by chemiluminescence generated wtih luminol following stimulation of MNC by fMLP. AR was measured by the delay (lag) in appearance of chemiluminescence (CL) generated by 2,2'-azobis-(2-amidinopropane) dihydrochloride (AAPH) and luminol; at pH 7.4 at 37°C. AAPH generates peroxyl radicals which with luminol generate CL. ROS generation by MNC did not increase significantly but antioxidant reserve (AR) fell significantly; post angioplasty (ANOVA F=5.16;.p<0.001). AR in the basal CS blood was significantly greater man those in the peripheral venous (PV)blood (p<0.05). The fall in AR may contribute to diminished bioavailability of nitric oxide (NO) as well as an increased availability of Superoxide (O₂) radical which is a vasoconstrictor and may synergize the effect of NO tack in causing vasoconstriction following angiopiasty.