Researchers have known for years about a risk of Parkinson's disease. But for the other so-called sporadic cases of the disease, which occur in the opinion of some scientists more commonly in rural areas, there was no explanation. To uncover a possible association, a team led by Tim Greenamyre from Emory University (US state of Georgia) rats injected the low-dose organic pesticide rotenone, classified as relatively harmless, for several weeks. The researchers present the results in the November issue of the journal Nature Neuroscience on Monday.
Greenamyre and colleagues observed a gradual decay of nerve cells in the brain with the transmitter substance dopamine during Rotenone administration in rats. In addition, the animals developed the same microscopic protein deposits in the midbrain substantia nigra known to Alzheimer's patients. The researchers suggest that the pesticide stimulates the production of so-called free radicals, which cause oxidative damage to cells and are suspected to trigger a number of degenerative diseases.
Rotenone is according to the report of the US researchers a preferred pesticide, which also kills fish and is used for the regulation of waters. The study does not prove that rotenone also causes Parkinson's disease in humans, says the team. But she urges caution when dealing with the remedy and also raises the question of whether environmental toxins in general, including pesticides, do not promote long-term certain diseases.dpa display