FYI - Bt Risk Negligible?

Martha Rosett Lutz lutzrun at
Thu Dec 6 23:36:56 EST 2001

Dr. Koehn wrote:

"I equate long term exposure to BT corn pollen and Roundup ready Soybeans to
smoking. Smoking takes some time to make you sick or more likely, to kill

Target site and mode of action need to be determined to analyze toxicity of
any sobstance.

One primary toxin in tobacco is nicotine--

1)  Nicotine is an acetylcholine agonist, and as such is a powerful
neurotoxin with a human LD50 of around 1 mg per kg.  Sub-acute exposure can
cause chronic effects due to inappropriate stimulation of neuromuscular
junctions (i.e. high blood pressure, and similar effect).  Acute exposure
can cause death via paralysis of the respiratory muscles.  (Target site is
the acetylcholine receptor.)

2)  Nicotine is metabolized in the human body to a substance known as NNK,
which is directly mutagenic (causes replication errors in DNA).  Therefore
it may act to initiate cancer.  (Target site is DNA.)

3)  Nicotine has been shown experimentally to inhibit apoptosis, which
means it can promote the development of neoplasms into clinical cancer, and
it can also interfere with chemotherapeutic agents whose primary
anti-cancer mechanism is via induction of apoptosis.  (Target site includes
cells of the immune system that mediate apoptosis.)

I'm not sufficiently familiar with Bt toxin to evaluate its similarity to
the above target sites and modes of action.  Can anyone provide evidence
that Bt toxin and nicotine have comparable target sites and modes of

Thanks for the assistance!

In Stride,
Martha Rosett Lutz


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