Angiogenesis (angio'gen'esis) -- the growth of new blood vessels -- is an important natural process occurring in the body, both in health and in disease.

Angiogenesis occurs in the healthy body for healing wounds and for restoring blood flow to tissues after injury or insult. In females, angiogenesis also occurs during the monthly reproductive cycle (to rebuild the uterus lining, to mature the egg during ovulation) and during pregnancy (to build the placenta, the circulation between mother and fetus).

The healthy body controls angiogenesis through a series of "on" and "off" switches:

• The main "on" switches are known as angiogenesis-stimulating growth factors

• The main "off switches" are known as angiogenesis inhibitors

When angiogenic growth factors are produced in excess of angiogenesis inhibitors, the balance is tipped in favor of blood vessel growth. When inhibitors are present in excess of stimulators, angiogenesis is stopped. The normal, healthy body maintains a perfect balance of angiogenesis modulators. In general, angiogenesis is "turned off" by the production of more inhibitors than stimulators.

READ MORE

References:
Folkman J. Tumor angiogenesis, in Harrision’s Texbook of Internal Medicine, 15th ed. Braunwald E, Fauci AS, Kasper DL, et al., eds. McGraw-Hill, New York, NY, 2000 pp.132-152

Li W, Talcott K, Zhai A, Kruger E, Li V. The Role of Therapeutic Angiogenesis in Tissue Repair and Regeneration Adv Skin Wound Care 2005;18:491-500