[Endothelium and reactive forms of oxygen]

Recent experimental findings suggest that we should now consider some diseases as "endotheliopathies" and some others as "ROS-pathies". The presented review summarizes our knowledge on the role of endothelium and reactive oxygen species (ROS) in physiological processes and diseases. The vascular endothelium provides vital and responsive infrastructure of vessels for the circulation of blood and homeostasis of all organs. Due to its exposure to mechanical, chemical and biological factors, including ROS and the nature of its responses to these insults, it is involved in a wide variety of disease processes. Oxidative stress occurs also in many human diseases. Our understanding of the role played by the endothelium and ROS in disease pathology are still insufficient. To determine if endothelial and ROS-induced changes in hypertension, atherosclerosis, ischemia/reperfusion etc. are the primary cause of specific diseases or merely secondary effects remains to be clarified in several areas from inflammatory processes to cardiovascular diseases. Protection of the endothelium and antioxidant therapy represents a potential successful therapeutic approach in different diseases. In the near future the endothelial and free radical research will surely clarify many of our still unanswered questions.