促血管生长蛋白质会加速动脉硬化的危险
【摘要】有研究指出：一项旨在通过刺激新血管再生从而促进血流量的实验结果显示，促血管生长蛋白质会加速动脉硬化的危险。【全文】Vessel-building protein may worsen atherosclerosisBy Merritt McKinneyNEW YORK, Mar 30 (Reuters Health) - An experimental therapy that aims to improve blood flow to the heart by stimulating the growth of new blood vessels may clog the arteries, researchers report.Mice and rabbits treated with a protein called vascular endothelial growth factor (VEGF) experienced substantial increases in atherosclerosis, the build-up of fatty plaques in arteries that can lead to a heart attack."We need to be very cautious about the widespread use of VEGF," the study's first author, Dr. Francesca Celletti of the World Health Organization in Geneva, Switzerland, told Reuters Health. "We have observed increased rates of atherosclerosis...in two different species. As for the effect in humans...we simply do not know yet. The point now is that we are going to have to look."VEGF stimulates the growth of new blood vessels. Recent research has focused on whether treatment with the protein or other similar growth factors may restore blood flow in people with blocked heart arteries, particularly those who are not good candidates for other types of artery-clearing treatment.Previous research has raised concerns about potential side effects of the treatment, including inappropriate growth of blood vessels, which may be harmful to people at high risk for conditions like cancer and diabetic retinopathy.Concerned that the formation of new blood vessels might also accelerate the growth of fatty plaques, Celletti's team tested a low dose of VEGF in mice that were prone to developing a condition similar to atherosclerosis.Writing in the April issue of the journal Nature Medicine, the researchers report that after mice received a single injection of VEGF, plaques were 4 to 14 times larger than before treatment. Celletti and her colleagues also detected signs that the plaques were becoming less stable, suggesting that they might be more likely to break free and clog arteries.The investigators achieved similar results when they tested VEGF in rabbits.Even though the findings occurred in animals, not people, Celletti and her colleagues call for further research into the effects of VEGF on plaques.The findings are "interesting," according to Dr. Valentin Fuster of Mount Sinai School of Medicine in New York, a past president of the American Heart Association, but "it's difficult to be certain of the implications," since the research was performed in animals, not humans, he said.The report "in no way" should discourage further study of VEGF in humans, Fuster told Reuters Health in an interview. However, he noted that researchers studying VEGF should pay close attention to whether similar effects do occur in humans.More than 800 people have been treated with VEGF or similar agents so far, and the rate of heart attacks or other heart problems has not been higher than expected 18 months or longer after treatment, according to Dr. J. Anthony Ware of the Albert Einstein College of Medicine in New York. This suggests that if VEGF increases plaques, the effect may by too small to cause serious problems, he notes in an editorial that accompanies the study.But in her comments to Reuters Health, Celletti pointed out that too little time has passed and too few patients have received VEGF therapy to be certain that the treatment does not lead to a dangerous increases in plaque."People previously didn't notice the fourfold increased rates of plaque formation in the two species we examined either," she said.But Celletti said that she and her colleagues might have found some ways around the problem. "In fact, we have developed alternative strategies to locally block the pro-atherosclerotic effect of VEGF," she said.Although Celletti cautioned that the results are preliminary, she said that they are "very promising." She and her colleagues are in the process of publishing the results of this research.SOURCE: Nature Medicine 2001;7:403-404, 425-429., http://www.100md.com