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

Physical exercise increases metabolic rate, and induces both adaptatio nal biogenesis of mitochondria in skeletal muscle and an increase in a ntioxidant capacity. The onset of experimental anorexia and cachexia c an be delayed by voluntary exercise. As skeletal muscle is the main ta rget for cancer cachexia, we determined the levels of coenzymes Q(9) a nd Q(10) in skeletal muscle from tumour-bearing exercising rats, and c ompared them to those of sedentary tumour-bearers and controls. Both t umour-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 demonstrate d an increase in the levels of both coenzymes (P < 0.05). In cardiac m uscle, the presence of tumour and exercise reduced the levels of coenz ymes below that of sedentary controls. Exercise counteracted the anaem ia in the tumour-bearing host (P < 0.05). In conclusion, the increase in antioxidant capacity in skeletal muscle indicates a defence mechani sm in the tumour-bearing hosts which is augmented by physical exercise .