No More Heart Disease Learning How To Prevent Heart Disease
by Dan Hammer
The Real Heart of Cardiovascular Health!
When is comes to taking care of your cardiovascular system little to no attention is given to your endothelial cells. Most all of the attention goes to your heart or your arteries and veins. Yet, more and more research is showing that the health of your heart, arteries, veins and all of your cardiovascular system is dependent upon the health of your endothelial cells. What are Endothelial Cells?
Endothelial cells are the thin layer of cells that line the interior surface of all blood vessels. It is sometimes referred to as the endothelium. It’s important to note that these cells line the entire circulatory system from the heart all the way down to the smallest capillary. When added up, the volume of these endothelial cells would cover the surface area of 8 tennis courts and weigh as much as the liver. That’s amazing since the endothelium is only one cell thick and can’t be seen by the human eye.
Once discovered the endothelium was classified as an inert membrane whose primary function was to keep the blood in the circulatory system and out of the body’s tissues and organs. However, research over the last 25 years has shown that the endothelium is an active, multi-functional organ that plays a vital role in metabolic, immunologic, and cardiovascular health. The endothelial cells ultimately determine the health of your blood vessels and play a major role in preventing cardiovascular disease.
Life Enhancing Functions of the Endothelial Cells!
Because the endothelial cells line every blood vessel they play an important role in the proper function of every organ in your body. This gate-keeping role varies for each organ system. For example, in the brain and retina the endothelial cells are tightly linked together to create a barrier that only allows selective molecules to pass through it. In the liver, spleen and bone marrow, the endothelial cells are loosely linked allowing for cellular trafficking between these intercellular gaps. However, in the kidneys, endocrine glands and intestinal villi, the endothelial cells have a different type of selective permeability to allow for efficient filtering, secretion and absorption based on that organ’s function.
The following is a list of the known functions of the endothelial cells. Each function plays an important role in cardiovascular health and your overall wellness:
Angiogenesis – The formation of new capillaries is called angiogenesis. It is regulated in part by the endothelial cells. This function is extremely important in wound healing. It also plays a significant role in muscle creation and in the heart’s ability to develop collateral vessels. These collateral vessels can help lessen the impact of a blood vessel blockage in the heart by providing alternative routes for blood flow.
Atherosclerosis – For developing countries, atherosclerosis is the most prevalent vascular disease. One of the functions of the endothelium is to facilitate blood flow. It does this by providing a smooth surface that inhibits platelet adhesion and clotting. It also tries to inhibit foreign substances from adhering to its cellular wall which can lead to plaque formations. Large molecules like cholesterol and/or toxic substances like nicotine damage the intercellular junctions between the endothelial cells allowing deposits to build up. This causes the smooth and flexible lining of your blood vessels to become rough and hard.
It is these plaque formations that are at the heart of atherosclerosis or hardening of the arteries. As this process continues over time, the deposits or plaques become larger which narrows the interior of the blood vessel making it harder for blood to pass through. This increases resistance to blood flow which can cause your blood pressure to increase. The following contributing factors can cause the endothelium to lose its ability to prevent these formations: smoking, diabetes, hyperlipidemia, hypertension or high blood pressure, and inflammation. Elevated homocysteine levels have also been associated with premature atherosclerosis.
Atherosclerosis was once thought to be irreversible but new studies clearly show that when the proper biochemical environment is provided the injured endothelium can return to its undamaged state. Proper supplementation with L-arginine, the precursor for Nitric Oxide, has been shown to diminish lesion formation and reverse endothelial dysfunction.
Blood Clotting – The narrowing of your blood vessels also causes blood turbulence that can lead to the formation of blood clots. These blood clots, if large enough or if they pass through too narrow of an opening, can eventually lodge themselves in a blood vessel causing a blockage. When this happens in the heart we call it a heart attack. When it happens in the brain it is called a stroke.
The endothelial cells produce a molecule called Nitric Oxide (NO) which is critical in the proper control of blood pressure. NO also inhibits platelet adhesion, activation, secretion and aggregation, as well as promoting platelet disaggregation. This is extremely important in preventing blood clots in the vascular system that can lead to heart attacks and strokes. It is also a critical factor in sickle cell anemia to help prevent red blood cells from changing, adhering to each other and clinging to the vascular walls. This helps to prevent blockages which cause most of the pain and tissue damage associated with sickle cell anemia.
While using NO to prevent blood clotting, it’s interesting to note that the endothelial cells are also necessary for blood to clot. They synthesize the vitally important molecule called Factor VIII or von Willibrand’s Factor which is essential for blood clotting. Without this molecule a person could bleed to death from a simple scratch.
Blood Pressure– Not only do the endothelial cells provide a dynamically-controlled structural barrier between the circulating blood and surrounding tissues and organs but they also produce signaling molecules that influence vasodilation and vasoconstriction. Vasodilation causes blood vessels to relax allowing for greater blood flow. This reduces blood pressure. Vasoconstriction causes blood vessels to tighten reducing blood flow and causing blood pressure to increase.
It is currently believed that the endothelial cells are the controlling factor in the regulation of blood pressure. They produce both Nitric Oxide (NO) which is the most potent vasodilator and Endothelin-1 the most potent vasoconstrictor. The proper production of NO is fundamental to maintaining normal blood pressures because it maintains basal tone by relaxing the vascular smooth muscle cells.
Specialized Barrier Function – Endothelial cells act as selective filters to regulate the passage of gases, fluid and various molecules across their membranes. This is especially important for the renal system and the brain.
It is also critical to the proper function of your immune system. Your white blood cells or leucocytes are produced in the bone marrow. They travel through the blood stream where the endothelial cells facilitate their passage into your body’s tissue to allow them to destroy foreign agents or antigens. Endothelial Cells Produce Nitric Oxide!
The health of your endothelial cells also plays a vital role in one other critical factor. In fact, the 1998 Nobel Prize in Medicine was awarded to three American researchers who discovered how the endothelial cells produced Nitric Oxide (NO). If you review the five major functions of the endothelium you will note that NO is critically involved in three of the five functions.
Who would have ever thought that an environmental pollutant and an extremely reactive and potentially dangerous free radical could also be the most important signaling molecule in your body! Since its discovery much has been learned about NO. For example:
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