Oxidative Stress and Endothelial Dysfunction during Sepsis

Abstract

The endothelium is an active tissue that plays a pivotal role in maintaining cardiovascular homeostasis. The endothelium ensures the quality of both the global and microcirculation. It forms an interface between blood and tissues. The human body contains approximately 10¹³ endothelial cells, an area of 4000 to 7000 m². This size is one of the reasons why endothelium must be considered an organ. Physiological functions of endothelial cells are: 1) to control vascular tone and blood flow by a local balance between vasodilators (paracrine release of diffusible vasodilator mediators, such as nitric oxide [NO], prostacyclin) and vasopressors (endothelin-1 [ET-1]); 2) to keep blood in a fluid state by preventing thrombosis; 3) to control the exchange of fluid and macromolecules between the blood and the tissues; and 4) to control the local balance between pro- and anti-inflammatory mediators.