Reactive Oxygen Molecules in the Kidney

Abstract

Reactive oxygen species (ROS) are produced as a normal consequence of aerobic respiration, as a response to immunologic stimulation, and as a by-product of many oxidationreduction reactions in living organisms. The kidney is a site of significant aerobic metabolism. In its role of maintaining fluid and electrolyte homeostasis, the kidney accounts for 10% of whole body oxygen consumption while making up less than 1% of total body mass1. Circulating immune elements (including neutrophils, monocytes, immune complexes) and activated intrinsic glomerular cells (macrophages, mesangial cells) are involved in a majority of glomerulonephritides2. ROS can mediate some of the glomerular damage. The arachidonic acid cascade, responsible for both vasodilator and vasoconstrictor substances essential to normal renal function, is both initiated by and a source of ROS3. However, the production of ROS is, under most circumstances, balanced by intrinsic antioxidant defenses4. Understanding the relationship between ROS production and antioxidant defenses will clarify the role of ROS in renal disease.