General Physiology and Biophysics Vol.28, No.1, p.16-23, 2009

The current study was undertaken to investigate the effects of NOx (plasma concentrations of nitrate plus nitrite which are plasma nitric oxide (NO) metabolites) over QT interval and to determine the level of correlation between them in conscious rabbits.

For this purpose, twenty-one New Zealand rabbits (5–7 months old) were used and randomly assigned into the following three groups: control (CG; n = 7, 1 ml isotonic NaCl solution per animal/day), L-arginine (ARG-G; n = 7, L-arginine solution 200 mg/kg/day) and L-NAME (NAME-G; n = 7, L-NAME solution 100 mg/kg/day). Injections were performed intraperitoneally at 9:00 a.m. for 9 days. Blood samples were collected 2 h after the injections on day 1, 5 and 9 and the concentration of plasma NOx was determined using a colorimetric method. ECG was also recorded 2 h after the injection on 1st, 5th and 9th days. The heart rate, QT intervals, corrected QT intervals (QTc) and QT dispersion (QTd), QTc dispersion (QTcd) values were calculated from the ECG recordings.