Vasodilation is the dilation (widening) of the blood vessels, which reduces the blood pressure (pressure the heart needs to apply to supply blood throughout the body). Substances which cause vasodilatation are known as Vasodilators. The primary function of vasodilators is to increase blood flow in the body to tissues or region that needs it the most. This often happens when a specific region or tissue is not receiving enough glucose, lipids or other nutrients. Vasodilators acts on the lining of the blood vessels in turn relaxing the blood vessels and reducing the blood pressure.
Controlling high blood pressure is very important because it puts lot of pressure on the heart and the arteries, which can lead severe damage over a period of time. High blood pressure increases the risk of heart attack, heart failure, stroke, and kidney failure. Vasodilators usually are prescribed in combination with other types of blood pressure drugs.
Few vasodilators used Nitroglycerin, Alprostadil, Minoxidil and Nesiritide.
Importance of nitric oxide (no) as a vasodilator
Nitric oxide is a gaseous cell signaling (signals that’s controls basic cellular activities and cell actions) molecule of great physiological importance in the human body. It is a strong vasodilator which directly acts on the blood vessels and reduces the blood pressure. Nitric oxide is produced in the body from essential amino acid L-arginine. The enzyme nitric oxide synthase (an enzyme produced by the cells lining the blood vessels) helps in the production of the nitric oxide from arginine and nitrates.
We find high concentrations of nitrates in beets, spinach, and other leafy vegetables. The nitrates in these foods get converted to nitrites by the action of the saliva on the foods. The gastric acid in the stomach converts he nitrites into nitric oxide. Nitric acid being a vasodilator then acts on the blood vessels and relaxes them in turn reducing the blood pressure. Some foods rich in nitrates include spinach, beetroot, celery, iceberg lettuce, carrots, parsley, cabbage, radishes, collard greens, etc.
Importance of flavonoids as a vasodilator
Flavanoids are secondary plant metabolites (secondary metabolites are compounds produced in chemical reactions occurring in plants) which also have a selective vasodilating effect on the blood vessels. Flavonoids play a very important role in enhancing the activity of the NO synthase enzyme. This enzyme speeds up the production of nitric oxide. Hence, foods like spinach, kale, broccoli, dark chocolate and hawthorn rich in flavonoids improves vasodilation by increasing the production of nitric oxide.
Vitamin C and Garlic – Vitamin C is known to increase the production of NO in the body. Foods rich in Vitamin C include citrus fruits, tomatoes, bell peppers, berries, kiwi, etc. Garlic contains a compound known as Quercetin. Quercetin is a flavonoid which increases NO levels in the body. Foods rich in quercetin include onions, garlic, apples, grapes and red wine.
Importance of L-arginine as a vasodilator
As mentioned earlier, endogenous NO is produced from the amino acid L-arginine (essential amino acid). Research suggests that foods rich in amino acid may enhance the production of nitric acid and in turn reducing blood pressure. Few examples of foods rich in amino acid include fish, chicken, eggs, milk, cheese and different kinds of nuts like walnuts, cashews and almonds. At times, L- arginine is taken as a dietary supplement by athletes in to get more stamina and energy.
Intake of foods rich in nitrates, flavonoids and L-arginine does not interfere with our normal daily medication. Natural vasodilators cannot replace our routine medication unless specified by the medical practitioner.