Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Chemists identify immune system mechanism for methamphetamine binges

16.03.2005


Chemists at The Scripps Research Institute have found evidence in laboratory studies that the immune system may be able to recognize methamphetamine and boost tolerance to the drug through an unusual vaccine-like mechanism. Their finding, if confirmed in human studies, could help explain why chronic users go on long binges with the illicit drug, also known as speed. The study could lead to new treatments for the drug’s addiction, they say.

Recent studies by others have documented the drug’s apparent ability to suppress the immune system, making abusers more vulnerable to diseases such as HIV. The new study is the first to suggest that the drug can engage the body’s defense system to attack methamphetamine in such a way that makes users inclined to use more of the drug, the researchers say. Their study, which paints a clearer picture of the drug’s effect on the immune system and its potential for abuse, was described today at the 229th national meeting of the American Chemical Society, the world’s largest scientific society. "Test animals injected with methamphetamine actually developed antibodies to the drug, which is highly unique for a molecule of its relatively small size," says study co-leader Kim Janda, Ph.D., a chemist at Scripps in La Jolla, Calif. Developing antibodies to the body’s invaders, such as viruses and bacteria, is normally a good thing and forms the basis of modern vaccines, he explains. But ironically, people who abuse methamphetamine may build up antibodies to the drug itself, so they require increasing amounts to get high, resulting in binging behavior, he says. "Without knowing it, they’re essentially vaccinating themselves against the drug, and that’s not a good thing as it requires more of the drug to get high," says Janda. His findings were first reported in a recent issue of the Journal of the American Chemical Society, the Society’s peer-reviewed journal.

In a test tube study designed to simulate the chemical reactions that occur with the drug when it enters the bloodstream, the researchers showed that methamphetamine reacts with glucose and proteins to form a larger-size "glycated" product. This product is then recognized by immune system components, stimulating the production of antibodies to the drug. In follow-up studies using mice, those injected with the drug developed antibodies to it. "Antibodies are usually produced only in response to large molecule invaders such as proteins, not to small drug molecules," Janda says. "Glycation acts like a linker that allows [the methamphetamine] to be displayed to the immune system, triggering a vaccine-like reaction."



Just as a vaccine is able to remove invading pathogens by using antibodies to the pathogen, antibodies to methamphetamine attack and begin to clear the drug, Janda says. If the antibodies prevent some of the drug from reaching its place of action in the brain’s pleasure center, users might require more of the drug because some of it is bound up by antibodies and "soaked up like a sponge," according to the researcher. "If the mechanism we proposed proves true in humans, then it will help explain why addicts go on prolonged binges, requiring more frequent intake and ever-increasing amounts of the drug in order to achieve a high," says Janda, who led the study with his former student, Tobin Dickerson, Ph.D., also a chemist at Scripps.

Other drugs of abuse, including nicotine and ecstasy (which is structurally similar to methamphetamine), might share a similar mechanism of action involving immune system recognition and a consequent rise in tolerance to the drug, Janda and his associates theorize. Tolerance refers to the capacity to have a decreased response to a drug after prolonged use. Increased drug tolerance raises the likelihood that a person will become addicted. "Right now, there’s nothing really effective in getting people off methamphetamine," says Janda, who believes that highly specific methamphetamine antibodies can be made in a laboratory and then used as a clinical treatment for addiction. In theory, antibodies to the drug could be mass produced and administered at therapeutic levels that are high enough to clear the drug from the body, he says. "Methamphetamine has become the ‘crack’ of the 21st century," Janda says. "We’re just starting to unravel its mechanism of addiction." Further studies of the drug are planned, he adds.

Methamphetamine is a powerful psychostimulant that goes by a number of common names, including "speed," "ice" and "crank." It is often made in make-shift laboratories using over-the-counter drug ingredients, particularly cold and allergy medicines. Available as a powder or crystal, the drug can be injected, snorted, swallowed and smoked to provide users with a sense of euphoria. Drug effects can last for up to 12 hours. Frequent use is associated with serious health problems, including memory loss, aggression, psychotic behavior, and potential heart and brain damage.

The Skaggs Institute for Chemical Biology (at Scripps) and the National Institute on Drug Abuse provided funding for this study. In addition to Janda and Dickerson, other study co-authors include Noboru Yamamoto and Diana Ruiz, also of Scripps.

The American Chemical Society is a nonprofit organization, chartered by the U.S. Congress, with a multidisciplinary membership of more than 159,000 chemists and chemical engineers. It publishes numerous scientific journals and databases, convenes major research conferences and provides educational, science policy and career programs in chemistry. Its main offices are in Washington, D.C., and Columbus, Ohio.

Michael Bernstein | EurekAlert!
Further information:
http://www.scripps.edu

More articles from Life Sciences:

nachricht Could this protein protect people against coronary artery disease?
17.11.2017 | University of North Carolina Health Care

nachricht Microbial resident enables beetles to feed on a leafy diet
17.11.2017 | Max-Planck-Institut für chemische Ökologie

All articles from Life Sciences >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: A “cosmic snake” reveals the structure of remote galaxies

The formation of stars in distant galaxies is still largely unexplored. For the first time, astron-omers at the University of Geneva have now been able to closely observe a star system six billion light-years away. In doing so, they are confirming earlier simulations made by the University of Zurich. One special effect is made possible by the multiple reflections of images that run through the cosmos like a snake.

Today, astronomers have a pretty accurate idea of how stars were formed in the recent cosmic past. But do these laws also apply to older galaxies? For around a...

Im Focus: Visual intelligence is not the same as IQ

Just because someone is smart and well-motivated doesn't mean he or she can learn the visual skills needed to excel at tasks like matching fingerprints, interpreting medical X-rays, keeping track of aircraft on radar displays or forensic face matching.

That is the implication of a new study which shows for the first time that there is a broad range of differences in people's visual ability and that these...

Im Focus: Novel Nano-CT device creates high-resolution 3D-X-rays of tiny velvet worm legs

Computer Tomography (CT) is a standard procedure in hospitals, but so far, the technology has not been suitable for imaging extremely small objects. In PNAS, a team from the Technical University of Munich (TUM) describes a Nano-CT device that creates three-dimensional x-ray images at resolutions up to 100 nanometers. The first test application: Together with colleagues from the University of Kassel and Helmholtz-Zentrum Geesthacht the researchers analyzed the locomotory system of a velvet worm.

During a CT analysis, the object under investigation is x-rayed and a detector measures the respective amount of radiation absorbed from various angles....

Im Focus: Researchers Develop Data Bus for Quantum Computer

The quantum world is fragile; error correction codes are needed to protect the information stored in a quantum object from the deteriorating effects of noise. Quantum physicists in Innsbruck have developed a protocol to pass quantum information between differently encoded building blocks of a future quantum computer, such as processors and memories. Scientists may use this protocol in the future to build a data bus for quantum computers. The researchers have published their work in the journal Nature Communications.

Future quantum computers will be able to solve problems where conventional computers fail today. We are still far away from any large-scale implementation,...

Im Focus: Wrinkles give heat a jolt in pillared graphene

Rice University researchers test 3-D carbon nanostructures' thermal transport abilities

Pillared graphene would transfer heat better if the theoretical material had a few asymmetric junctions that caused wrinkles, according to Rice University...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

Event News

Ecology Across Borders: International conference brings together 1,500 ecologists

15.11.2017 | Event News

Road into laboratory: Users discuss biaxial fatigue-testing for car and truck wheel

15.11.2017 | Event News

#Berlin5GWeek: The right network for Industry 4.0

30.10.2017 | Event News

 
Latest News

NASA detects solar flare pulses at Sun and Earth

17.11.2017 | Physics and Astronomy

NIST scientists discover how to switch liver cancer cell growth from 2-D to 3-D structures

17.11.2017 | Health and Medicine

The importance of biodiversity in forests could increase due to climate change

17.11.2017 | Studies and Analyses

VideoLinks
B2B-VideoLinks
More VideoLinks >>>