CREATINE-KINASE RELEASE FROM ISOLATED EDL MUSCLES IN CHRONIC ETHANOL-TREATED RATS

Chronic ethanol abuse has been shown to cause damage to skeletal muscl e in animals and patients as reflected by elevated serum levels of cyt osolic enzymes and histological examination. The present study investi gated the hypothesis that elevated serum creatine kinase levels in eth anol-treated animals vs. sucrose control animals may result from incre ased enzyme release or efflux from muscle. Creatine kinase release was measured from extensor digitorum longus (EDL) muscles isolated from r ats chronically treated for 28 weeks with ethanol and from sucrose fed controls. The in vitro cumulative release of creatine kinase over a 2 -h period was significantly higher in the ethanol-treated animals. Con sistent with an increased release of enzyme into the bath, creatine ki nase levels in muscle homogenates at the end of the incubation period were lower in the ethanol-treated animals. Creatine kinase levels in s erum obtained from trunk blood samples were statistically higher in th e ethanol-treated animals compared to sucrose controls. These findings demonstrate increased enzyme release from fast-twitch skeletal muscle in chronic ethanol-treated rats.