U. scientist's snail-toxin research could bring new hope to patients

Parkinson's disease, nicotine addiction, Alzheimer's, depression, schizophrenia — some day, some or all may be treatable by medicines developed as a result of snail-toxin research led by a University of Utah scientist.

The research was announced in a study scheduled for publication Friday in the Journal of Biological Chemistry. The leader of the team was Dr. J. Michael McIntosh, physician, research professor of biology and professor of psychiatry.

A compound derived from the poison of the carnivorous marine snail Conus omaria was used in the study, McIntosh said in a telephone interview.

"We were able to clone genes for this and a number of related compounds from various species of cone snails," he said. "We then synthetically made the molecules that those genes encoded, and then we tested them to see which of those compounds have the most desirable properties."

The particular compound called "alpha conotoxin OmIA" turned out to be one that latches onto receptors in the brain that are tuned to nicotine, as well as to chemicals that occur naturally in the human system.

These chemicals, called neurotransmitters, include dopamine, serotonin and norepinephrine.

Dopamine is a chemical that "rewards" the brain, telling it that it's done something good and prompting a repetition. "That's one of the problems with drugs of abuse ... they trigger the release of excess dopamine."

The chemical also is important in controlling the body's motor movement.

"Too little dopamine causes symptoms seen in Parkinson's disease," McIntosh added.

Serotonin and norepinephrine are important in mood ailments such as depression and bipolar disorder, he said.

The three neurotransmitters affect the same receptors in the central nervous system as does nicotine.

"There are a number of diseases that in some way relate to nicotonic receptors," McIntosh said.

Some, like Alzheimer's, are related to memory.

"Being able to boost or reduce these levels of neurotransmitters has a wide variety of potential medical applications," he said.

The snail compound may be a tool in designing molecules that will act at particular receptor sites, he said. It also provides information about how the material works.