Q. What depletes the nitric oxide in the smooth muscles of the blood vessels?
Nitric oxide is the most potent dilator, or you might say relaxant of smooth muscle, that the body makes. This is a product of the endothelial cells of the intima (a one cell lining of the most interior part of a blood vessel wall.) It is a very neat system to keep blood pressure down and to protect the heart against a heart attack. When the oxygen level in a muscle drops the nitric oxide kicks in to dilate the arteries to feed the muscle more blood, and hence more oxygen.
There are many causes of endothelial dysfunction, that will ultimately in some way or another impair nitric oxide production or function. Dr. Esselstyn has listed these inhibitors of endothelial function and entities that prevent relaxation and dilation of the blood vessels. Anything that makes the blood sticky: Any animal product such as cheese, meat, and milk due to the animal fat and protein. Too much sugar, too much oil, including vegetable oil, olive oil, and shortening. Even though these oils may not contain cholesterol and are polyunsaturated, the fat itself impairs endothelial function by making the blood vessels sticky. Also anything that constricts the blood vessels will work against nitric oxide including caffeine, tobacco smoke, and chocolate, to name just a few. Hope this helps.