Comparative study on the effect of acetylcarnitine and carnitine on experimental hypoxic heart failure and their interactions with strophanthin K

Experiments on Langendorff's guinea pig heart showed that, when 0.1M acart (acetylcarnitine) or cart (carnitine) was given at 1 ml/min for 5 min, both prevented heart failure from hypoxia. The beneficial effects of acart were more powerful than those of cart.In isolated rabbit right atria, when acart or cart (0.05 ml of 0.04 M) was followed by strophanthin K (3.75 μg), acart+strophanthin K increased significantly contraction amplitude, but cart+strophanthin K didnot. Acart or cart (0.1 ml of 0.04 M)were found to significantly shorten the duration of rhythm disorder-induced by strophanthin K (50 μg). The duration of rhythm-disorder in the former (1.17±0.44 min) was significantly shorter than that in the latter (2.67±0.33 min).LD_(50) of acart and cart in mice were 1228 mg/kg and 974 mg/kg, respectively.It is concluded that acart was more effective and less toxic than cart in the treatment of heart failure.