Angiogenesis refers to the body’s ability to grow and develop new blood vessels. This is a normal process, which helps us to recover from illnesses, grow when we are children, and keep the supply of oxygen to tissues at a desirable level. It is particularly helpful when we have any type of wound, like a cut or scrape, a puncture, or a surgical wound. When the body is healthy, angiogenesis occurs, helping restore the skin to health. Women also go throw a normal angiogenesis cycle each month during their reproductive years; new blood vessels are key to forming the uterine lining that is shed monthly during menstruation.
The body has angiogenesis growth factors and inhibitors, and the process could be compared to turning a switch on and off. The on switch communicates that new blood vessels are needed, and growth factor chemicals in the body exceed inhibitors. When inhibitor chemicals in the body exceed growth factors, the process of angiogenesis is switched off.
In certain diseases, angiogenesis may occur too often or not enough. For instance, cancer can create too many blood vessels to develop, which feed cancer tissue and help it to metastasize. At the same time abnormal tissue is being nurtured, healthy tissue may be dying. Often, diseased cells are coded to produce more blood vessels, and important research in this area is attempting to find ways to turn this process off. Other diseases where too many blood vessels can actually lead to tissue death include those like diabetes, macular degeneration and rheumatoid arthritis.
Other illnesses work in the reverse, inhibiting the development of new blood vessels. Most forms of heart disease for instance, significantly reduce the chemical compounds that would stimulate new blood vessels to grow and replace diseased ones. In instances of stroke, failure of angiogenesis to occur can result in significant tissue death in the brain, which then may affect function. Here again, medical researchers need to find out a way to flip the switch to “on” to help those with insufficiency of new blood vessel growth.
Thus far, the Food and Drug Administration (FDA), has seven cancer therapy treatments considered antiangiogenic, and some encouraging results have been obtained from using these to treat colorectal cancer, neck cancer, breast cancer, and pancreatic cancer. Long-term studies on the effectiveness of these drugs will help reveal more about their benefits and possible problems. There are several angiogenic drugs (meant to stimulate blood vessel growth) that are being studied as possibly useful in the treatment of heart disease. The FDA has not yet approved these.
Some scientists liken our growing understanding of angiogenesis to the development of antibiotics, and suggest that this area of study may provide cures for thousands of diseases, since many diseases either accelerate or inhibit new blood vessel growth. They argue the process is a common factor to most diseases and may lead us to much better ways to manage disease in the future.