# Frog Poison Crosses Globe



## imgreen (Dec 20, 2006)

After more than a decade of work, a California researcher thinks he has
solved the 40-year mystery of where poisonous South American frogs get
their deadly neurotoxin — and surprisingly, the lead came from birds in
New Guinea.

The poison has been used for centuries by indigenous Colombians to coat
the points of their tiny blow darts, allowing them to bring down large
prey — as well as humans — with relative ease.

Called batrachotoxin — from the Greek batrachos , or frog — the lethal
agent is 10 times as deadly as the tetrodotoxin from the puffer fish.
Simply handling the frogs that secrete it from their skin can be fatal.

Ornithologist John P. Dumbacher of the California Academy of Sciences in
San Francisco and his colleagues reported this week in the Proceedings of
the National Academy of Sciences that the ultimate source of the poison
was most likely little-studied beetles in the Melyridae family.

The discovery is of more than academic interest, because batrachotoxin is
widely used in studying the function of sodium channels — gates in the
cellular membrane that are implicated in a variety of diseases, including
multiple sclerosis.

Those who work with the toxin must get it from the National Institutes of
Health, which collected a small supply 25 years ago. That supply is
running out, and researchers cannot collect more in Colombia because of
political turmoil there. The discovery could lead to new ways to collect
the useful poison.

Dumbacher got a lead in 1992, when he heard from people in New Guinea
about a bird called a pitohui that caused numbing or burning sensations
when eaten. He ultimately found batrachotoxin in five species of pitohui.

Elders in the tiny New Guinea village of Herowana told team members about
a beetle they called nanisani that produced numbing or tingling sensations
when touched.

Samples of the beetles, of the Choresine genus of the Melyridae family,
were collected for the scientists, who analyzed them and found the toxin.
They also found the remains of the beetles in the birds' stomachs.

Significantly, Melyridae beetles are also found in Colombia.

Dumbacher cautioned that the team was not sure that the beetles produced
the toxin; they might collect it from a plant instead.

That might be better in the long run, he added, because a plant would be
easier to grow in the laboratory.

Either way, a new source of the toxin appears to be just over the horizon


By Thomas H. Maugh II LA Times Staff Writer


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## sbreland (May 4, 2006)

Very interesting. GLad to see they are making some headway in this area and hopefully we'll have an answer on it eventually. If you don;t mind me asking, where did you find this article?


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## rozdaboff (Feb 27, 2005)

A citation for this (with the date) would be very helpful. I went to the PNAS site, and didn't see the article listed in the upcoming issue.


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## elmoisfive (Dec 31, 2004)

Well we have this...

http://www.pnas.org/cgi/content/abstract/0407197101v1

and this....

http://pubs.acs.org/cen/news/8245/8245notw8.html

Not exactly yesterday's news...perhaps the day before yesterday :wink: 

Bill


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## rozdaboff (Feb 27, 2005)

The day before, the day before yesterday...

No wonder I wasn't finding it quite so easily in the upcoming issue :? 

But I guess a search would have done wonders.


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## Catfur (Oct 5, 2004)

This also came up on DB here a while back, my Search Fu isn't up to par with finding it, though.


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## Ryan (Feb 18, 2004)

I remember this also, but non the less, cool to read again.


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## elmoisfive (Dec 31, 2004)

The older post...

http://www.dendroboard.com/phpBB2/viewtopic.php?t=3781

Bill


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