Pesticide link to Parkinson's

Monday, 6 November, 2000, 00:57 GMT - A commonly used organic pesticide
produced symptoms similar to Parkinson's disease when small amounts were
injected into rats over time.

It adds weight to theories that repeated exposure to low levels of
agrochemicals may also be causing cumulative damage to the human brain.

The pesticide Rotenone, frequently used as an insecticide and as a method
of killing fish, is considered relatively benign compared to many
commercially available chemicals.

But scientists now believe it interferes with cells in the brain which
produce a chemical called dopamine.

Lack of dopamine produces the well-known Parkinsonism symptoms such as
tremor, rigidity and difficulty moving.

The loss of key brain cells is presently irreversible, and worsens over
time, eventually leading to death.

The cause of Parkinson's Disease is largely unknown, with cases appearing
sporadically and apparently at random, leading some scientists to think it
could be caused by long-term exposure to environmental toxins.

Because of the current lack of knowledge about the origins of the illness,
the only acknowledged risk factor is age - the older you are, the more
likely you are to get it. Approximately 1% of people over the age of 65
develop the illness.

To test the chemical link, Dr Tim Greenamyre from the Emory University in
Georgia, US, administered Rotenone intravenously over a period of weeks to
rats.

Not only did the rats develop some of the physical symptoms of Parkinson's,
but scans revealed actual changes in their brains which appear similar to
changes in the brain of a Parkinson's patient.

The research is published in the journal Nature Neuroscience.

The team believes Rotenone may be causing cell components called
mitochondriae to release damaging molecules called free radicals, which go
on to affect the dopamine-producing brain cells.

Professor Adrian Williams, chairman of the medical advisory panel of the
Parkinson's Disease Society, said it was possible that pesticides did cause
Parkinson's in some patients - but the likelihood was it was only a small
minority.

He said it was possible a minority of patients had a genetic make-up which
made them more vulnerable to the effects of pesticides than normal.

He told BBC News Online: "It is unlikely that all cases of Parkinson's are
caused by pesticides, but it may be that one or two in every hundred are.

"It would be wrong to expect that a condition such as Parkinson's is caused
by a single factor."

Professor Williams also warned of the dangers of drawing conclusions based
on experimental research on animals.

Separate research, published in the journal Science, supports the theory
that free-radical damage is behind the development of Parkinson's.

A team from the University of Pennsylvania School of Medicine has
identified a protein which, when damaged by free radicals, could trigger
the onset of Parkinson's.

When the physical brain changes associated with Parkinson's were examined,
a protein, called alpha-synuclein, was found in an altered state there, but
not elsewhere.

This change to the protein could have been caused by free radicals.


Related to this story:
Hope of Parkinson's 'cure' (27 Oct 00 | Health)
Jobs 'linked to Parkinson's' (11 Sep 00 | Health)
Parkinson's disease breakthrough (05 Sep 00 | Health)

Internet links:
Science
Nature Neuroscience
Parkinson's Disease Society

BBC News Online: Health
http://news.bbc.co.uk/low/english/health/newsid_1004000/1004375.stm

janet paterson, an akinetic rigid subtype parkie
53 now /44 dx cd / 43 onset cd /41 dx pd / 37 onset pd
TEL: 613 256 8340 URL: http://www.geocities.com/janet313/
EMAIL: [log in to unmask] SMAIL: POBox 171 Almonte Ontario K0A 1A0 Canada