Preservation of mitochondrial respiratory function by coenzyme Q10 in aged rat skeletal muscle.

Pharmacological intervention was investigated into the age-associated decline in mitochondrial function. Rats aged 7 weeks were divided into two groups; the control group (standard diet), and the coenzyme Q10 group (fed with 0.2% coenzyme Q10 diet). Mitochondria from skeletal muscle (psoai major) and cardiac muscle were prepared from rats aged 7, 35, and 55 weeks, and enzymic activities were measured in four complexes of the mitochondrial electron transport chain. Age-associated declines in activities of complexes I and IV of psoai major were significantly mitigated in the coenzyme Q10 group. The activities of complexes I and IV of heart mitochondria did not change significantly throughout the experiment in either group. Moreover, aging up to 55 weeks had no significant effect on activities of complexes II and III in either tissue. It is concluded that intake of a coenzyme Q10 rich diet might retard the normally observed age-associated decline in overall mitochondrial respiratory function in rat skeletal muscle.