Peroxynitrite in reperfusion arrhythmias and its whole blood chemiluminescence results.

The aims of the present study were to investigate the effects of exogenous peroxynitrite (ONOO(-)) on reperfusion arrhythmias in anaesthetized rats, and to detect endogenous and exogenous ONOO(-)-induced chemiluminescence (CL) signals in rat whole blood, which was collected during baseline and in the first minute of reperfusion. ONOO(-) infusion in ischemia/reperfusion (I/R) applied groups caused significant decreases in mean arterial pressure (MAP) and heart rate (HR). Ventricular fibrillation (VF) incidences in the vehicle, ONOO(-), and dec-ONOO(-) infused groups were 63, 100, and 20%, respectively. In control group CL signal was 136+/-34mV during the resting period and was increased to 336+/-57mV with reperfusion. Also, the effects of SOD+CAT, L-NAME and urate were investigated. Ventricular tachycardia (VT) incidence was decreased significantly in SOD+CAT and urate; VF incidence was decreased significantly in SOD+CAT applied groups. CL signals were inhibited with SOD+CAT, L-NAME, and urate. Exogenous ONOO(-) infusion during I/R was also investigated. CL signal in exogenously ONOO(-) infused group is increased 423% during reperfusion. Only urate infused group VF incidence was decreased significantly. CL signals of ONOO(-) infused groups were inhibited by SOD+CAT, L-NAME, and urate. Based on the results of the current study, ONOO(-) seems to be one of the key mediators of reperfusion arrhythmias in anaesthetized rats.