Skeletal muscle lipid peroxidation and differential messenger rna expression in cocaine and/or ethanol treated rodents

Cocaine (C) and ethanol (EtOH) abuse has been shown to damage skeletal muscle. It is hypothesized that C and/or EtOH cause skeletal muscle damage via the formation of free radicals leading to lipid peroxidation. The present study investigated the combined effects of C and EtOH on skeletal muscle lipid peroxidation using thiobarbituric acid reactive substance's (TBARS), total glutathione levels and protein expression using differential messenger RNA expression. Male Harlan Sprague Dawley rats (280 - 300 g) were injected IP for Days 1-15 with either normal saline (NS), EtOH (2.2 g/kg), C (15 mg/kg) or C+EtOH. All animals received C and EtOH on Day 16, followed by the appropriate treatment group for Days 17-19, EtOH on Day 20 and sacrificed on Day 21. There was no statistically significant treatment effect in the basa! or stimulated TBARS in either the gastrocnemius or anterior tibialis muscles. Likewise, total glutathione levels were not statistically lower in the gastrocnemius or tibialis anterior muscles in the C and/or EtOH animals compared to normal saline. In contrast, a initial survey using PCR-based differential messenger RNA expression assays in rodent extensor digitorum longus (EDL) muscles identified the presence and/or absence of distinct bands in animals treated with C/EtOH or C compared to those treated with NS and EtOH. Supported by NIDA RO3 DA09602 (GAB) and ABMRF Grant (JP).