(A) Carnitine-acylcarnitine translocase (CACT)-dependent respiration in rat, interfibrillar cardiac mitochondria at baseline and in the presence of cocaine, cocaethylene, and the cocaine metabolites ecgonine and benzoylecgonine (all 1 mM concentration). Both cocaine and cocaethylene significantly depress respiration (* p < 0.05). All data points plotted with median line.
(B) Representative Dixon plot of cocaine-based inhibition of carnitine-dependent respiration. Cocaine produced a non-competitive inhibition of carnitine-dependent respiration.
(C) Representative Dixon plot of cocaethylene based inhibition of carnitine dependent respiration. Cocaethylene produced a non-competitive inhibition of carnitine dependent respiration.
(D) Inhibitory constants (Ki) of CACT for both cocaine and cocaethylene. All data points plotted with median line.