"You have this kind of balance, but with aging there is this shift," said Gioscia-Ryan, who works in Professor Douglas Seals' Integrative Physiology of Aging Laboratory at CU-Boulder. "There become way more reactive oxygen species than your antioxidant defenses can handle."
That phenomenon, known as oxidative stress, occurs when the cells of older adults begin to produce too much superoxide and other reactive oxygen species. Mitochondria are a major source of superoxide in aging cells. The increased superoxide not only interacts with nitric oxide and the endothelium, but can also attack the mitochondria themselves. The damaged mitochondria become increasingly dysfunctional, producing even more reactive oxygen species and creating an undesirable cycle.
Past studies have looked at whether taking antioxidant supplements long term could improve vascular function in patients with cardiovascular disease by restoring balance to the levels of superoxide, but they've largely shown that the strategy isn't effective.
This new study differs because it uses an antioxidant that specifically targets mitochondria. Biochemists manufactured MitoQ by adding a molecule to ubiquinone (also known as coenzyme Q10), a naturally occurring antioxidant. The additional molecule makes the ubiquinone become concentrated in mitochondria.
"The question is, 'Why aren't we all just taking a bunch of vitamin C?" Gioscia-Ryan said. "Scientists think that, taken orally, antioxidants like vitamin C aren't getting to the places where the reactive oxygen species are being made. MitoQ basically tracks right to the mitochondria."
The findings of the study indicate that the strategy of specifically targeting the mitochond
|Contact: Rachel Gioscia-Ryan|
University of Colorado at Boulder