COENZYMES Q(9) AND Q(10) IN SKELETAL AND CARDIAC-MUSCLE IN TUMOR-BEARING EXERCISING RATS

Physical exercise increases metabolic rate, and induces both adaptational biogenesis of mitochondria in skeletal muscle and an increase in antioxidant capacity. The onset of experimental anorexia and cachexia can be delayed by voluntary exercise. As skeletal muscle is the main target for cancer cachexia, we determined the levels of coenzymes Q(9) and Q(10) in skeletal muscle from tumour-bearing exercising rats, and compared them to those of sedentary tumour-bearers and controls. Both tumour-bearing groups had increased levels of coenzymes Q(9) and Q(10) in the anterior tibial muscle (P < 0.05 for exercised animals). In the soleus muscle, only the tumour-bearing exercising animals demonstrated an increase in the levels of both coenzymes (P < 0.05). In cardiac muscle, the presence of tumour and exercise reduced the levels of coenzymes below that of sedentary controls. Exercise counteracted the anaemia in the tumour-bearing host (P < 0.05). In conclusion, the increase in antioxidant capacity in skeletal muscle indicates a defence mechanism in the tumour-bearing hosts which is augmented by physical exercise.