Does increased oxidative stress cause hypertension?
Hypertension is associated with increased vascular oxidative stress; however, there is still a debate whether oxidative stress is a cause or a result of hypertension. Animal studies have generally supported the hypothesis that increased blood pressure is associated with increased oxidative stress; however, human studies have been inconsistent. Oxidative stress promotes vascular smooth muscle cell proliferation and hypertrophy and collagen deposition, leading to thickening of the vascular media and narrowing of the vascular lumen. In addition, increased oxidative stress may damage the endothelium and impair endothelium-dependent vascular relaxation and increases vascular contractile activity. All these effects on the vasculature may explain how increased oxidative stress can cause hypertension. Treatment with antioxidants has been suggested to lower oxidative stress and therefore blood pressure. However, to date, clinical studies investigating antioxidant supplements have failed to show any consistent benefit. It is noteworthy that lowering blood pressure with antihypertensive medications is associated with reduced oxidative stress. Therefore, it seems that oxygen stress is not the cause, but rather a consequence, of hypertension.
Grossman
Ehud
E
Internal Medicine D and Hypertension Unit, The Chaim Sheba Medical Center, Tel-Hashomer, 52621 Israel. grosse@post.tau.ac.il
D000818:Animals; D000975:Antioxidants / Q000627:therapeutic use; D001794:Blood Pressure / Q000187:drug effects / Q000502:physiology; D001808:Blood Vessels / Q000503:physiopathology; D004195:Disease Models, Animal; D002149:Energy Intake; D006801:Humans; D006973:Hypertension / Q000188:drug therapy / Q000453:epidemiology* / Q000209:etiology; D009589:Nitrogen Oxides / Q000378:metabolism; D009765:Obesity / Q000209:etiology; D018384:Oxidative Stress / Q000502:physiology*; D010101:Oxygen Consumption; D051381:Rats; D017382:Reactive Oxygen Species / Q000378:metabolism; D014664:Vasodilation
D000975:Antioxidants; D009589:Nitrogen Oxides; D017382:Reactive Oxygen Species