ROS in the aging male: Model diseases with ROS-related pathophysiology

The aging process is a complex biological phenomenon that can be attributed to several mechanisms. ROS (reactive oxygen species) activity is widely considered one of them, as it is associated with extensive damage in a variety of cells. For example, the gradual decrease in fertility often accompanying aging males can be traced back to oxidative stress, since ROS are released throughout life from the mitochondrial respiratory chain. Cumulative intracellular damage as a result of the increased ROS concentration affects all tissues that perform aerobic metabolism and, owing to blood circulation, anaerobic tissues as well. Naturally, other mechanisms such as cell inflammation and lack or incapacity of antioxidant enzymes also contribute to the variety of systematic distortions that characterize aging. Finally, the particularly elevated number of adult men that show, among others, a gradual deterioration in reproductive functions suggests a central role of ROS generation in senescence in general and male aging, in particular. (C) 2009 Elsevier Inc. All rights reserved.