And then there were many.

And then there were many

Angiogenesis -- the growth of new blood vessels -- is a necessary part of fetal development, but in the adult it causes problems. New vessels interfere with the functioning of arthritic joints, allow the growth of tumors and interfere with retinal functionl in the eyes of many diabetics.

Clifford A. Barger of Harvard University has found that angiogenesis also occurs within the walls of thickened atherosclerotic arteries, and has proposed that leakage from these new vessels may spark heart attacks (SN: 3/16/85, p. 170).

Scientists have long sought the biological trigger of angiogenesis.

Recently, two competing Harvard University laboratories found apparently different angiogenic proteins (SN: 10/5/85, p. 213), and now another Harvard group, led by Bruce R. Zetter, has found yet another molecule that initiates angiogenesis in fat deposits on the surface of the heart.

If the discovery is confirmed, Zetter says, it will provide another correlation between fat and heart disease, and explain how some currently used drugs fight heart disease.

Zetter and his colleagues failed to find an angiogenic factor in the vessel walls of atherosclerotic arteries. But they did find it in the fat in which the coronary arteries are embedded. The activity of the as-yet uncharacterized factor is blocked by a prostaglandin inhibitor, suggesting that prostaglandin inhibitors may work by preventing new blood vessel formation in coronary artery walls.