Isotachophoretic evidence for energy-preservating effect of coenzyme Q10 on isolated guinea-pig cardiac muscle.

Effects of coenzyme Q10 (CoQ10) on hypoxia-induced changes in ATP, NAD and NADH levels were studied in the isolated atrial and ventricular muscles of guinea-pigs. Guinea-pigs were pretreated with CoQ10 (60 mg/kg/day, i.p.) or the solvent for 3 consecutive days before initiation of study. The concentrations of ATP, NAD and NADH were determined by isotachophoresis. The concentrations of ATP and NAD contained in the atrial or ventricular muscle decreased with increasing incubation time with hypoxic Tyrode's solution (pO2 not equal to 160 mmHG), but that of NADH increased. However, the ATP and NAD concentrations of atrial and ventricular muscles from CoQ10-pretreated animals tended to be higher than those from solvent-pretreated ones. Moreover, the increase in NADH concentration during hypoxia tended to be less in the CoQ10-pretreated preparation than in the solvent-pretreated one. These results suggest that the pretreatment with CoQ10 leads to the increase in CoQ10 content in mitochondria of heart muscle, thereby permitting the improvement of oxidative phosphorylation in the mitochondria during hypoxia.