Our body is endowed with the unique ability to grow new blood vessels. You can see this process in real time, such as after you break your knee. After an injury the normal blood supply is affected: there is a lack of oxygen (hypoxia) in the injured area. This lack of oxygen triggers the growth of new blood vessels. Cells lining the vessel walls (endothelial cells) respond to hypoxia by producing vascular endothelial growth factor (VEGF).
VEGF promotes the growth and function of blood vessels. And this is just the tip of the iceberg: it not only helps in the formation of new blood vessels, but also plays a critical role in protecting the brain and activating glucose transport.
The concept of VEGF includes a whole group of proteins with very diverse properties. The first to be discovered was VEGF-A, which is currently the best studied. It was followed by the discoveries of VEGF-B, C, D, E and F.
The VEGF-A protein is not only the most studied, but also the most abundant. It exists in different forms, which differ in different amounts of amino acids. In this material, we will focus specifically on VEGF-A.
The VEGF-A protein is the most common form.
Hypoxia as a driver of growth
Hypoxia provides the strongest impetus for vascular growth. It doesn't matter whether the lack of oxygen is localized or occurs throughout the body, for example on a trip to the mountains. As soon as the tissue cells no longer receive enough oxygen, the hypoxia-inducible factor (HIF) is activated, which stimulates growth via the vascular endothelial growth factor VEGF.
The existing capillary network is transformed first. Those areas that previously remained passive are connected to the functioning of the network. The regeneration of the lateral branches of the arteries, the blood supply of which is limited, takes place. Under the influence of hypoxia the layer of muscle tissue strengthens and the diameter of muscle fibers increases.
In the case of a long trip to the mountains or during hypoxic-hyperoxic training, small capillaries grow in the inner wall of the arteries. Under the influence of VEGF, individual endothelial cells detach from the tissue layer and use it to form small tubular outgrowths. They gradually elongate and connect at the base. In this way a healthy capillary network grows and is incorporated into the process of blood circulation.
Because hypoxic training has a complex effect, capillary density increases throughout the body, but primarily in the damaged tissue areas.
VEGF and heart function
VEGF protects the coronary arteries of the heart. It improves their function and widens the vasculature by incorporating small vessels into it. This dense vasculature of the coronary arteries provides the best protection for the heart.
In patients with cardiovascular disease, the physician may recommend that patients improve the blood supply, for example, with interval hypoxic training. After therapy, blood flow to the heart muscle continues despite vascular calcification, and painful angina comes less frequently. The condition of the vessels also determines how the patient can survive a heart attack, as well as the likelihood of a second heart attack.
VEGF and brain function
VEGF is present in all parts of the brain. The highest concentration of this protein is found in the hypothalamus, the main center for controlling brain activity.
In addition to providing for growth and function, VEGF is also present in the brain.
While many positive effects of VEGF on the body are already known, there is still much to learn about this powerful factor. But one thing is certain: VEGF plays a vital role in human adaptation and regeneration mechanisms.