Association between Testicular Atrophy and Muscular Atrophy after Ethanol Administration

Ethanol produces multiple organ injuries, including liver damage, muscle atrophy, and testicular atrophy. Because androgenic steroid hormones are produced by testicular Leydig cells, ethanol-induced testicular atrophy may affect androgenic steroid hormones and produce an anabolic effect. The aim of the present study was to investigate whether ethanol-induced testicular atrophy affects the increase in protein catabolism and muscular atrophy. Male Sprague-Dawley rats were pair-fed a high-fat, low-protein diet containing ethanol or isocaloric dextrose for 6 weeks. Testicular weight and levels of plasma and testicular testosterone were measured. Urinary 3-methyhistidine was measured as a marker of protein catabolism. The sizes of type I (soleus muscle) and type II (anterior tibial muscle) muscle fibers were analyzed morphometrically. The gastrocnemius was examined with electron microscopy. Testicular atrophy and decreased plasma levels of testosterone were observed in ethanol-fed rats. The urinary 3-methyhistidine/creatinine ratio was higher in ethanol-fed rats than in control rats. The mean diameters of type I and II muscle fibers were less in ethanol-fed rats than in control rats. Electron microscopy showed injury to structures of the gastrocnemius in ethanol-fed rats. These results suggest that ethanol-induced testicular atrophy is associated with an increase in protein catabolism, resulting in muscular atrophy.