Enzyme might be target for treating smoking, alcoholism at same time

September 12, 2011

An enzyme that appears to play a role in controlling the brain's response to nicotine and alcohol in mice might be a promising target for a drug that simultaneously would treat nicotine addiction and alcohol abuse in people, according to a study by researchers at the Ernest Gallo Clinic and Research Center, affiliated with the University of California, San Francisco.

Over the course of four weeks, mice genetically engineered to lack the gene for (PKC) epsilon consumed less of a nicotine-containing water solution than normal mice, and were less likely to return to a chamber in which they had been given nicotine.

In contrast, normal mice steadily increased their consumption of nicotine solution while the mice lacking PKC epsilon did not.

The study was conducted by Gallo senior associate director and investigator Robert O. Messing, MD, UCSF professor of neurology, and Gallo researcher Anna M. Lee, PhD.

In normal mice, as in humans, nicotine binds to a certain class of nicotinic receptors located on dopamine neurons, which causes dopamine to be released in the brain. Dopamine creates a feeling of enjoyment, and thus prompts a sense of reward. Lee and Messing found that mice lacking PKC epsilon are deficient in these nicotinic receptors.

The study appears in the online Early Edition of the for the week of September 12, 2011.

The finding complements earlier research in which Messing found that mice genetically engineered to lack the PKC epsilon enzyme drank less alcohol than normal mice and were disinclined to return to a chamber in which they had been given alcohol.

"This could mean that these mice might not get the same sense of reward from nicotine or alcohol," said Messing. "The enzyme looks like it regulates the part of the reward system that involves these ." The reward system is a complex of areas in the brain that affect craving for nicotine, alcohol and other addictive substances.

The next step in the research, said Messing, would be to develop compounds that inhibit epsilon. The ultimate goal, he said, would be medications that could be used "to take the edge off of addiction by helping people get over some of their reward craving."

Explore further: Nicotine triggers the same brain reward circuitry as opiates

More information: “Protein kinase C epsilon modulates nicotine consumption and dopamine reward signals in the nucleus accumbens,” by Anna M. Lee and Robert O. Messing, PNAS.

Related Stories

Nicotine triggers the same brain reward circuitry as opiates

June 15, 2005

In experiments with mice, researchers have found that nicotine triggers the same neural pathways that give opiates such as heroin their addictively rewarding properties--including associating an environment with the drug's ...

Dissecting the machinery of nicotine's reward

June 14, 2006

Understanding what makes people crave the high of nicotine is a key to developing treatment for this highly addictive drug. And that understanding involves tracing the neural machinery by which nicotine switches on the brain's ...

New compounds may treat both alcohol and cigarette addictions

November 3, 2010

Researchers at the Ernest Gallo Clinic and Research Center at the University of California, San Francisco, and Pfizer Inc., have determined that two new compounds may be effective in treating both alcohol and nicotine dependence ...

Recommended for you

Forensic DNA analysis checks the origin of cultured cells

August 31, 2016

Cell lines are cultured cells that are commonly used in medical research. New results from Uppsala University show that such cells are not always what they are assumed to be. Using genetic analyses, the researchers showed ...

A new key in fighting Kennedy's disease

August 31, 2016

If a disease affects motoneurons, cells that control voluntary muscle activity, researchers should focus their efforts on motoneurons to find potential treatments, right?

0 comments

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.