Vascular ageing: the role of oxidative stress.

Vascular ageing can be envisioned as the consequence of the accumulation of reactive oxygen species (ROS) associated with generalized endothelial dysfunction. Oxidative stress arises when the balance between production and removal of ROS favours the pro-oxidation arm. Therefore, ROS have been traditionally considered to be only a toxic by-product of aerobic metabolism. However, it has become apparent that ROS might control many different physiological processes, such as stress response, pathogen defence and systemic signalling. This has lead to the hypothesis that a certain level of ROS is needed physiologically, so much so that an overly increased antioxidant potential might be deleterious for health. Recent evidence has strengthened this notion by correlating cellular response with oxidants and the mechanisms that regulate longevity. Here, we overview current literature on this topic and we will try to convince the reader of the importance of balanced oxidative stress for vascular integrity and healthy ageing.