THURSDAY, March 16, 2006 (HealthDay News) -- The toxic chemical sarin, a potential bioterrorism agent, causes devastating, long-term damage to genes controlling memory, mood, thinking, muscle control and numerous other brain functions, U.S. researchers report.
"Our new findings confirm that the duration of sarin exposure can continue for years or even decades after the initial exposure because it alters gene expression of proteins critical to brain function," study senior author and Duke University pharmacologist Dr. Mohamed Abou Donia said in a prepared statement.
In 1995, subway riders in Tokyo were exposed to sarin during a terrorist attack, and many veterans of the Gulf War were exposed to low levels of sarin during the destruction of Iraq's chemical arsenal. That exposure has been linked to cases of chronic fatigue, muscle and joint pain, weakness, loss of concentration, forgetfulness and irritability.
The new findings, published in the March 15 issue of Biochemical Pharmacy, may explain many of the neurological, psychological and physical problems suffered by people who've been exposed to sarin, which is an organophosphate.
The Duke team found that within 15 minutes of a single exposure to sarin, 65 different genes in the brains of rats showed altered expression, with levels of protein production either increasing or decreasing.
"We have witnessed and catalogued the severe symptoms that victims of sarin exposure have experienced, and we have studied the severe damage sarin imposes on brain cells. Now, we have evidence that implicates specific genes that are damaged when one is exposed to sarin," Abou Donia said.
Three months after the rats were exposed to sarin, 38 genes in their brains remained altered. Three months in rats is equivalent to about 20 years in humans. This suggests that the effects of sarin in humans are widespread and long-lasting.
The study results may eventually lead to the development of a blood test for sarin exposure and could help identify potential genes to target to treat people exposed to sarin, the researchers said.
The U.S. Centers for Disease Control and Prevention has more about sarin.