Effects of exogenous ubidecarenone on cardiac action potential and activation time in hypoxic, glucose-free solution. Possible antiarrhythmic action of ubidecarenone.
Effects of ubidecarenone (coenzyme Q10, CoQ10, E-0216) on the cardiac action potential depressed by the superfusion with hypoxic, glucose-free solution (modified Tyrode solution) and on the activation time (ACT) altered by the same means were investigated. In the control specimens, the action potential duration (APD) was markedly shortened and action potential amplitude (AMP) reduced. The maximum rate of rise of phase zero Vmax) and the resting membrane potential (RMP) were slightly affected. Superfusion with exogenous CoQ10 significantly reversed the depressed APD and AMP, and tended to increase RMP and Vmax. Moreover, the ACT which, in the control, was slightly shortened until after the 10th min of superfusion became progressively longer. It was slightly prolonged during the first 10 min, and from the 12th to the 15th min was slightly shortened by treatment with CoQ10. These results suggest that CoQ10 could evoke an antiarrhythmic action in cardiac cells in depressed metabolic conditions.
Tsutsumi
T
T
Division of Cardiology, Showa University Fujigaoka Hospital, Yokohama, Japan.
Sekiya
S
S
Okazaki
O
O
Harumi
K
K
D000200:Action Potentials / Q000187:drug effects; D000818:Animals; D000889:Anti-Arrhythmia Agents; D003067:Coenzymes; D005947:Glucose / Q000502:physiology; D006168:Guinea Pigs; D006321:Heart / Q000187:drug effects* / Q000502:physiology / Q000503:physiopathology; D066298:In Vitro Techniques; D010100:Oxygen / Q000502:physiology; D013997:Time Factors; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000633:toxicity
D000889:Anti-Arrhythmia Agents; D003067:Coenzymes; D014451:Ubiquinone; C024989:coenzyme Q10; D005947:Glucose; D010100:Oxygen