EFFECT OF ALCOHOL AND ELECTRICAL-STIMULATION ON LEAKAGE OF CREATINE-KINASE FROM ISOLATED FAST AND SLOW MUSCLES OF RAT

Binge drinking of alcohol may lead to acute alcoholic myopathy with rh abdomyolysis, which is characterized by skeletal muscle damage, elevat ed serum creatine kinase (CK), and myoglobinuria. This study was under taken to test whether alcohol acts directly on the skeletal muscles to enhance the leakage of CK, and to assess the influence of fiber-type composition and repetitive contractions of the muscle on the effect of alcohol. After 4 hr of incubation in normal physiological solution at 37 degrees C, mean leakage of CK was 0.7 units/mg from isolated rat e xtensor digitorum longus (EDL), which has more fast-twitch glycolytic muscle fibers, and 1.2 units/mg from the soleus, which has more slow-t witch oxidative muscle fibers. Ethanol at 0.1, 0.2, and 0.5% concentra tions caused significantly greater increase in leakage of CK from sole us than from EDL. In normal physiological solution, electrical stimula tion at 1 Hz for 4 hr increased the leakage of CK by about the same de gree in both EDL and soleus. In the presence of 0.1 and 0.2% ethan of, electrical stimulation markedly potentiated the alcohol-induced leaka ge of CK from both soleus and EDL. These results indicate that alcohol increases the leakage of CK by acting directly on skeletal muscle fib ers, especially of the slow-twitch oxidative type, and that repeated m uscle contractions potentiate the alcohol effect. These studies sugges t that exercise may increase the chances of rhabdomyolysis in the alco holics.