Effect of the selective mitochondrial KATP channel opener nicorandil on the QT prolongation and myocardial damage induced by amitriptyline in rats

Objectives The aim of this study is to evaluate the protective effect of nicorandil, a selective mitochondrial K-ATP channel opener, on QT prolongation and myocardial damage induced by amitriptyline. Methods The dose of amitriptyline (intraperitoneal, i.p.) that prolong the QT interval was found 75 mg/kg. Rats were randomized into five groups the control group, amitriptyline group, nicorandil (selective mitochondrial K-ATP channel opener, 3 mg/kg i.p.) + amitriptyline group, 5-hdyroxydecanoate (5-HD, selective mitochondrial K-ATP channel blocker, 10 mg/kg i.p.) + amitriptyline group and 5-HD + nicorandil + amitriptyline group. Cardiac parameters, biochemical and histomorphological/immunohistochemical examinations were evaluated. p < 0.05 was accepted as statistically significant. Key findings Amitriptyline caused statistically significant prolongation of QRS duration, QT interval and QTc interval (p < 0.05). It also caused changes in tissue oxidant (increase in malondialdehyde)/anti-oxidant (decrease in glutathione peroxidase) parameters (p < 0.05), myocardial damage and apoptosis (p < 0.01 and p < 0.001). While nicorandil administration prevented amitriptyline-induced QRS, QT, QTc prolongation (p < 0.05), myocardial damage and apoptosis (p < 0.05), it did not affect the changes in oxidative parameters (p > 0.05). Conclusions Our results suggest that nicorandil, a selective mitochondrial K-ATP channel opener, plays a protective role in amitriptyline-induced QT prolongation and myocardial damage. Mitochondrial K-ATP channel opening and anti-apoptotic effects may play a role in the cardioprotective effect of nicorandil.

Automated summary

This study evaluated the protective effect of nicorandil on QT prolongation and myocardial damage induced by amitriptyline. The results showed that nicorandil could prevent the electrophysiological changes and myocardial damage caused by amitriptyline.