Tarantula venom could be drug source

And you thought tarantula venom was a bad thing.

Not always, according to researchers who have isolated a substance in the spider’s venom that could lead to drug treatments for conditions as diverse as muscular dystrophy, urinary incontinence and cardiac arrhythmias.

Scientists at the University at Buffalo have shown that a natural compound called GsMTx4 found in the venom can block channels through the membrane walls of cells. Specifically, it blocks channels that are opened by a stretching in the surface of cell membranes. These “stretch-sensitive” channels are an unusual part of cell biology.

And an important one, because these channels let calcium into the cell. Calcium plays an important role in tissue. It is involved in such functions as the heart and bloodstream’s response to blood pressure changes as well as the filling of hollow organs such as the bladder. But when the channels become hyperactive - spending more time open than closed – they can cause health problems.

Fred Sachs, professor of biophysics in the university’s Center for Single Molecule Biophysics, and his research team discovered recently that the mirror image of GsMTx4 can prevent a cell from undergoing dangerous stretching.

After experimenting with venoms from scorpions, centipedes and spiders, Sachs says the research team (none of whom report being afraid of the creepy crawlers) found through “pure luck” that the compound in the venom of the Chilean Rose tarantula worked to numb these mechanical senses in cells – the same effect that an anesthetic has on the body.

The large Chilean Rose tarantulas used in Sachs’ research are about 6 inches across. They are harmless, he says, and are sold in the United States as pets.

“Nature doesn’t give up its secrets very easily,” Sachs says. “She’s a rather private individual and to keep asking these questions is an ongoing challenge to no end.”