Scorpion has welcome sting for heart bypass patients

Oct 22, 2010

A toxin found in the venom of the Central American bark scorpion (Centruroides margaritatus) could hold the key to reducing heart bypass failures, according to research from the University of Leeds.

The study, published online in , reports that one of the scorpion's toxins, margatoxin, is at least 100 times more potent at preventing neointimal hyperplasia – the most comon cause of bypass graft failure - than any other known compound.

Neointimal hyperplasia is the blood vessel's response to injury. It triggers the growth of new cells, causing chronic obstruction on the inside of the vessel.

When a vein is grafted onto the heart during a bypass procedure, the injury response kicks in as the vein tries to adapt to the new environment and different circulatory pressures. Whilst the growth of new cells helps to strengthen the vein, the internal cell growth restricts blood flow and ultimately causes the graft to fail.

The potency of the margatoxin in suppressing the injury response mechanism took the team by surprise, says lead author Professor Beech from the University's Faculty of Biological Sciences. "It's staggeringly potent. We're talking about needing very few molecules in order to obtain an effect."

The works by inhibiting the activity of a specific potassium ion channel - a pore in the cell membrane that opens and closes in response to electrical signals and indirectly enhances delivery of a intracellular messenger, the calcium ion.

"We knew from experimental research in immunology that the ion channel Kv1.3 is involved in activating immune system responses and that it's linked with chronic inflammation problems in the immune system, such as those you see with multiple sclerosis," says Professor Beech. "Since our own studies had identified Kv1.3's presence in injured blood vessels, which are also often complicated by chronic inflammation, we wanted to see if the same blockers would inhibit neointimal hyperplasia."

"There were a number of good blockers of this ion channel available to screen. Several compounds are developed from plants, and one comes from ," he says, "but margatoxin was the most potent of all these compounds by a significant margin."

Professor Beech says margatoxin would probably be unsuitable as a drug that could be swallowed, inhaled or injected, but it could potentially be taken forward as a spray-on treatment to the vein itself once it's been removed and is waiting to be grafted onto the heart.

Explore further: Serotonin neuron subtypes: New insights could inform SIDS understanding, depression treatment

Related Stories

'Electronic switch' opens doors in rheumatoid joints

Jan 02, 2008

A breakthrough in understanding the way atoms move across cell membranes in the human body could pave the way for the development of new treatments for inflammatory diseases such as rheumatoid arthritis.

Teaching an old drug new tricks

Jan 30, 2009

A century-old drug that failed in its original intent to treat tuberculosis but has worked well as an antileprosy medicine now holds new promise as a potential therapy for multiple sclerosis and other autoimmune diseases.

Drug-coated stents less risky for heart bypass patients

Jan 22, 2009

Coronary bypass surgery may carry less risk of serious complications if stents coated with a drug that suppresses cell growth are used in the procedure rather than bare-metal stents, UT Southwestern Medical Center researchers ...

Unraveling the mysteries of poison

Apr 13, 2006

Researchers from the Max Planck Institite for Biophysical Chemistry and other German and French colleagues have combined magnetic resonance spectroscopy (solid-state NMR) with special protein synthesis procedures to uncover ...

Chloroform provides clue to 150 year old medical puzzle

Mar 31, 2008

One of the earliest general anaesthetics to be used by the medical profession, chloroform, has shed light on a mystery that’s puzzled doctors for more than 150 years – how such anaesthetics actually work.

Recommended for you

User comments : 0

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.