Bioenergetic effect of liposomal coenzyme Q₁₀ on myocardial ischemia reperfusion injury

The antioxidant and bioenergetic effects of CoQ₁₀ are well known but its clinical utility is limited by the requirement for enteral administration. A newly developed liposomal CoQ₁₀ (CoQ) is water soluble and capable of intravenous administration. The purpose of this study is to determine the mechanism by which acute administration CoQ protects myocardium from reperfusion (Rp) injury. Rats were pretreated with CoQ 10 mg/kg i.v. 30 min prior to the experiment. Control rats were pretreated with liposome only. Hearts were excised and subjected to equilibration, 25 min of normothermic ischemia and 40 min of Rp on a Langendorff apparatus. At end Rp, CoQ hearts recovered 74 ± 5% of their DP vs. 50 ± 9% in control (p < 0.05). Aerobic efficiency was maintained (0.66 ± 0.02 vs. control, 0.5 ± 0.04, p < 0.003) and CoQ hearts lost less CK activity vs. control (p < 0.02). PCr and ATP were higher than control (p < 0.05, 0.02, respectively). Results show that i.v. CoQ improves recovery of function, aerobic efficiency, CK activity, and recovery of PCr and ATP after Rp. This suggests that acute administration of liposomal CoQ improves myocardial tolerance to I/R via its role as an antioxidant as well as improving oxygen utilization and high energy phosphate production.