Chronic Alcohol Consumption In Female Mice Yields Strain Dependent Differences In Muscle Atrophy

Abstract

Differences in alcohol preference between mouse strains is well known, yet there are no reports of whether alcohol non-preferring mice experience alcoholic myopathy. PURPOSE: To determine whether the intake and response to chronic alcohol feeding differs between alcohol preferring (C57BL/6) and non-preferring (CD2F1) mice. METHODS: Female C57BL/6 (n=16) and CD2F1 (n=6) mice aged 12-weeks-old were acclimated to a liquid diet (1 wk) prior to randomization into either a control (CON) or alcohol (EtOH) treatment group: B6-CON, B6-EtOH, CD2-CON, and CD2-EtOH. Alcohol was incorporated into the diet and daily consumption of EtOH was assessed relative to body weight. After 7 weeks the gastrocnemius (GAS), tibialis anterior (TA), and quadriceps (QUAD) muscles were excised, weighed and are expressed relative to body weight. Blood was collected from the vena cava and separated into plasma for blood EtOH concentration at time of sacrifice (BAC). The spleen and heart were also removed and weighed. Data were analyzed via 2-way ANOVA for variables across time, and unpaired t-tests were used to detect differences within each strain. RESULTS: A group x time interaction was observed for EtOH consumed (F=3.010, p<0.001), where B6-EtOH consumed a greater amount of EtOH compared to CD2-EtOH weeks 3-7 (p≤0.038). However, at time of sacrifice, no differences were observed for BAC between the strains (p=0.22). Alcohol intake reduced GAS weight similarly in both strains (B6: -9.67 ± 4.15%; p=0.037; CD2: -12.07 ± 3.19%; p=0.019), and muscle weights also did not differ between strains following alcohol intake (p=0.06). QUAD weight was also reduced by alcohol consumption in the CD2 mice (-17.68 ± 4.56%; p=0.02), while no significant atrophy was observed in the B6 mice. Conversely, B6 mice had a significant reduction in heart weight following chronic alcohol intake (p=0.014; -13.03 ± 4.58%), while the CD mice showed no effect. Finally, alcohol feeding did not alter spleen weight or TA weight in either strain (p>0.05). CONCLUSION: The non-alcohol preferring CD2F1 mice experienced a greater loss of muscle mass in response to chronic alcohol feeding, despite consistently consuming a lower dose of alcohol. Future work will be needed to determine what molecular pathways contributed to the enhanced catabolic effect of alcohol in this strain of mice.