What is Cerebrovascular Disease (CVD)?
So, what is this cerebrovascular disease that is killing millions worldwide?
Cerebrovascular refers to the blood vessels (arteries) that supply blood to the brain, and cerebrovascular disease, in simple terms, refers to an abnormality of the brain due to a disruption in this blood supply in some way. This causes the brain cells to be deprived of oxygen as the blood is responsible for carrying oxygen to all of our body cells. The brain cells will then die or be damaged under this condition.
The most common type of cerebrovascular disease is stroke, also known as cerebrovascular accident. Stroke is caused by either a clogged blood vessel in the brain, or when the blood vessel in the brain bursts or leaks. Other CVD include: transient ischemic attack (TIA), multi-infarct (arteriosclerotic) dementia and reversible ischemic neurologic deficit (RIND).
Roles of Nitric Oxide (NO)
Nitroglycerin and related vasodilating compounds increase the diameter of a blood vessel, and were found to act to release nitric oxide, an endothelium-derived relaxing factor (EDRF). Endothelium cells are cells that line the blood vessels and prevents the interaction of blood cells with the vessel walls.
The discovery of the role of nitric oxide in the human body was made by Robert F. Furchgott (hD), Louis J. Ignarro (PhD) and Ferid Murad (MD, PhD). This is one of the most important progress made in the study of cardiovascular medicine and the three were awarded the Nobel Prize in Medicine in 1998.
Nitric Oxide is a small gaseous, signaling molecule in the cardiovascular system produced by healthy endothelial cells. Signaling molecules have the function of producing another substance, the second messenger. The second messenger transmit messages along signal pathways between cells.
When NO enters a cell, it activates an enzyme called guanylate cyclase, which produces the second messenger, cyclic GMP. This second messenger relaxes and dilates the blood vessels.
So how do nitric oxide prevent strokes and cerebrovascular diseases? Nitric oxide lowers blood pressure, a high risk factor for both stroke and heart attack. By relaxing and dilating the blood vessels, it promotes healthy blood circulation to the brain and heart. It also causes coronary arteries to widen to increase blood flow to the heart.
Other roles of NO includes keeping arteries flexible, reverses arterial plaque and suppresses atherosclerosis. By preventing platelets and white blood cells from sticking to the vessel wall, NO can prevent atherosclerosis. Atherosclerosis is the accumulation of deposits of fatty wax like materials, cholesterol, calcium, waste products, and other substances along the insides of the arteries.
In addition, nitric oxide can reduce the production of free radicals, which causes blood vessels to age rapidly, and suppress abnormal growth of vascular muscle cells to prevent blood vessels from thickening.