Source: Emory University Health Sciences CenterPrint this pageDate: 2003-11-10
URL: http://www.sciencedaily.com/releases/2003/11/031110054609.htm
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very important experiment - every cell of our body is powered by the mitochondria it contains - with this mitochondria in each cell containing more genes than does the human genome within the same cell! If the mitrochondria is weakened, then effectively our immune system also loses strength.
Several Commonly Used Pesticides Are Toxic To Mitochondria In Laboratory
Experiments
Scientists at Emory University School of Medicine have found in laboratory experiments
that several commonly used pesticides are just as toxic or even more toxic to
the mitochondria of cells than the pesticide rotenone, which already has been
implicated in the development of Parkinson's disease. The Emory neurologists,
led by Tim Greenamyre, MD, PhD and Todd B. Sherer, PhD, will present the results
of their comparative research with pesticides at the Society for Neuroscience
meeting in New Orleans on Saturday, Nov. 8.
Parkinson's disease, which is one of the most common neurodegenerative diseases,
has been associated abnormalities of mitochondria, which are the "power
plants" that provide all cells with energy. Rotenone and many other pesticides
are known to damage the mitochondria by inhibiting a mitochondrial enzyme called
complex I. In earlier experiments, Dr. Greenamyre and his colleagues found that
chronic treatment with low levels of rotenone caused gradual degeneration of
the dopamine neurons in rats, and reproduced many of the features of Parkinsonism.
In the new study, the Emory scientists exposed human neuroblastoma cells to
the pesticides rotenone, pyridaben, fenazaquin, and fenpyroximate, all of which
inhibit complex I. Pyridaben was by far the most potent toxic compound, followed
by rotenone and fenpyroximate, with fenazaquin being the least toxic. Pyridaben
was also more potent than rotenone in producing "free radicals" and
oxidative damage to the cells, both of which are thought to be important in
causing Parkinson's disease.
"These results show that commonly used pesticides are toxic to cells, and
may cause the kinds of cellular damage that lead to diseases such as Parkinson's,"
Dr. Sherer says. "Although our study does not prove that any particular
pesticide causes Parkinson's, it does lead to more questions about the safety
of chronic exposure to these environmental agents and certainly warrants additional
research." Last year Emory created a new Emory Collaborative Center for
Parkinson's Disease Environmental Research through a grant of more than $6.5
million from the National Institute of Environmental Health Sciences.
"For quite a while scientists have believed that environmental factors,
including pesticides, may be important in causing Parkinson's disease,"
Dr. Greenamyre says. "We are continuing our research to determine exactly
how these exposures cause nerve cell damage and death."
Other Emory scientists involved in the research study were Gary W. Miller, PhD,
associate professor in Emory's Rollins School of Public Health, and neurologists
Alexander Panov, PhD and Jason Richardson, PhD.
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This story has been adapted from a news release issued by Emory University Health
Sciences Center.
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