Jump to content
RemedySpot.com

Cone shell snail toxin in Prialt medication (pain research)

Rate this topic


Guest guest

Recommended Posts

Researcher risks killer snails for study

http://www.cp.org/english/online/full/science/041103/g110310A.html

by ALICIA CHANG

POTSDAM, N.Y. (AP) - Jon- Bingham puts his life on the line every

week for the sake of science. One wrong move, and he could become the

hapless victim of a snail attack that could kill him.

Bingham, a biochemist at son University, is a self-described

" conehead " whose livelihood depends on scuba diving for tropical marine

cone snails and coaxing them to discharge their venom in his laboratory.

" It's like snake-charming, " he said with a grin.

Cone snails churn out a cocktail of toxins, each with its own unique

chemical properties. Scientists are studying these poisons with the hope

of turning them into potential drugs that could one day treat chronic

pain, epilepsy and neurological disorders such as Alzheimer's.

For centuries, shell collectors have bagged cone shells for their

intricately patterned armor. Cone snails are among the sea's most

abundant creatures with more than 500 species, and are mostly found in

coral reef environments in the IndoPacific region.

But cone snails are potentially dangerous, especially the fish-eating

types. There is no antidote if a person gets stung. Usually, the victim

is paralyzed and can't breathe, and is immediately placed on respiratory

support in the emergency room. Recovery can take several hours to a few

weeks.

In unfortunate cases, a person can die within an hour of being stung.

Some 30 people have been reported killed by cone snails during sea

expeditions dating back to the 1930s.

Several companies worldwide are testing different cone snail toxins in

animals and humans. The most advanced work is being done by Elan Corp.,

a biotechnology company based in Dublin, Ireland, which is trying to get

Food and Drug Administration approval for its pain-killer Prialt.

Prialt is synthetically made from a naturally occurring toxin from the

marine snail Conus magus, and works by blocking nerve channels in the

body responsible for transmitting pain signals.

The drug, which is injected into the fluid surrounding the spinal cord,

reduced severe chronic pain in human patients in three experiments

carried out by the company.

Scientists believe cone snail venom may someday be used in pain

management as an alternative to or in tandem with morphine, but without

morphine's addicting side effects. Yet its use may be limited because of

the way it's administered, said Goldstein, a pain researcher at

Indiana University and a board member of the American Society for

Clinical Pharmacology and Therapeutics.

To get venom from snails, most scientists either dissect dead cone

snails found in nature or create it chemically in the lab.

Bingham thinks he can reap a more diverse mixture of toxins by milking

cone snails in captivity. He is one of the few scientists in the world

who farms cone snails in his lab nestled in the northern foothills of

New York's rustic Adirondack Mountains near the Canadian border.

Bingham, a 33-year-old Australian who has milked snails for over a

decade, has never been stung and he never wants to be. But just in case

there's an accident, his medical file at the Canton-Potsdam Hospital

down the road from the university contains instructions on how to treat

a sting.

Baldomero Olivera, a biologist at the University of Utah and a pioneer

in the field, used to milk cone snails in his lab, but hardly does it

anymore because the task became too monotonous.

" The problem with milking is that it's quite tedious, " Baldomero said.

Not only do researchers need to perform several milkings to get a good

sample, but how much venom they collect is also dependent on the cone

snails' behavior on a particular day, he said.

Olivera, who has been studying cone snails since the 1960s, discovered

early on that certain snail venom _ made up of protein-like molecules

called peptides _ can work as an anesthetic.

In the 1980s, students in his lab injected different snail toxins into

the nervous systems of mice. Depending on the type of toxin, the mice

acted differently. Some would shake and others would sleep, leading

scientists to isolate the chemical properties of the venom for potential

medicinal use.

In 1996, Olivera and a colleague founded Cognetix Inc., a privately held

biopharmaceutical company based in Salt Lake City that studies cone

snail venom.

One day recently, Bingham demonstrated the milking process.

Inside Bingham's lab is an average-sized fish tank carrying an ominous

warning on the lid: " Danger! Venomous Snails. " Nine fish-eating snails

collected from Panama four years ago live in the tank filled with salt

water and beach sand for them to bury themselves. Only the largest one _

at 2 1/2 inches _ is named: Big Bertha.

With his bare hands, Bingham took a pair of long metal forceps, stirred

the water and waited. The ripple effect caused the elephant trunk-like

noses of the cone snails to slowly poke out of the sand.

Like a surgeon getting ready for an operation, Bingham got everything in

order. He gingerly picked up the snails with the forceps, lined them all

up on one side of the tank and counted them to make sure none was hiding

in the sand _ a potential recipe for a surprise sting.

Now the milking can begin.

Hunching over the tank, Bingham dangled the bait _ an unsuspecting

goldfish _ in his left hand using a pair of forceps. Behind the fish,

Bingham held a small plastic container shaped like an inverted triangle

with a piece of non-lubricated condom slipped over the opening.

The trick, Bingham explained, is to entice the snails to sting the fish

and release their venom into the container.

Big Bertha, smelling the fish, inched forward and whipped out her

harpoon-like proboscis. She stung the fish, but her proboscis failed to

penetrate the condom. No venom was released into the container.

Looking disappointed, Bingham tried again.

Lying in wait like a hunter, he got into position and eyed his gloveless

hands holding the trap. The room is silent. Bingham wrinkled his nose

and licked his lips.

Another snail came forward toward the twitching, paralyzed fish. This

time, its proboscis penetrated the fish's tail straight through the

condom, pumping poison into the container. The milking was over in the

wink of an eye.

Out of four tries that day, only one milking was successful. Bingham got

a droplet of the venom no larger than a poppy seed. On good days, he

gets much more. The next step is to put the poison in the freezer where

its chemical content will be studied later.

Scientists studying cone snail poison have found that a single snail can

produce up to 100 different kinds of toxins. Now they're trying to find

out why and how it happens.

" These animals are like craps players, " Bingham explained. " Every time

they roll the dice, they make a new compound. "

___

On the Net:

son University: http://www.clarkson.edu

Elan Corp: http://www.elan.com

American Society for Clinical Pharmacology and Therapeutics:

http://www.ascpt.org/

© The Canadian Press, 2004

Link to comment
Share on other sites

Join the conversation

You are posting as a guest. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...