WEDNESDAY, March 24, 2004 (HealthDayNews) -- American scientists have identified a molecule that appears to play a critical role in the potentially fatal brain swelling caused by high doses of lead.
They report their discovery in this week's online edition of the Annals of Neurology.
The researchers also identified a drug that prevents the swelling in an animal model of lead poisoning.
"Our findings are in rodents and need to be confirmed in humans," senior author Dr. John Laterra, a professor in the departments of neurology, neuroscience and oncology at Johns Hopkins University School of Medicine and the Kennedy Krieger Research Institute, says in a prepared statement.
If these findings are confirmed in humans, that would warrant further research to determine whether the same molecule, called vascular endothelial growth factor (VEGF), plays a role in cognitive problems seen in children who experience smaller, more gradual exposures to lead.
In this study, young rats who ingested high concentrations of lead accumulated the metal in their brains. This accumulation was accompanied by significant edema, as well as increases in VEGF.
Laterra and his colleagues also found a drug that blocked the ability of VEGF to effect molecular changes inside cells prevented edema in the rats with the high doses of lead.
"It is possible that VEGF pathway inhibitors. . . could be used to prevent the development of brain swelling in children acutely intoxicated with lead. It is also possible that other, more subtle, cognitive aspects of low-level lead toxicity are caused by changes in VEGF levels," Laterra says.
Flakes of, and dust containing, old lead-based paints pose a threat to small children.
The U.S. National Institute of Environmental Health Sciences has more about the dangers of lead.