Scientists Discover New Brain System That Counters Effects of Opioid Drugs

National Institute on Drug AbuseFOR IMMEDIATE RELEASE, Thursday, Oct. 10, 1996, Mona W. Brown, Sheryl Massaro

Researchers funded by the National Institute on Drug Abuse (NIDA) have discovered a neuronal system in the brain that modulates and opposes the action of the brain's own opioid system. The discovery of the actions of orphanin FQ (OFQ), a natural brain chemical, could provide the foundation for the development of effective pain-killing drugs without some of their negative side effects. These latest findings by Dr. David K. Grandy and colleagues at the Oregon Health Sciences University, appeared in the October 3, 1996 issue of Neuroscience.

According to Alan I. Leshner, Ph.D., Director of NIDA, "This discovery opens up a new avenue of research in the development of medications that maximize the pain relieving qualities of drugs such as morphine -- critical in the treatment of cancer patients, for example -- while minimizing their negative effects. Additionally, this research may eventually help us to further understand how and why individuals develop drug tolerance and experience unpleasant withdrawal symptoms," Dr. Leshner added. While morphine is the principal drug used for controlling severe pain for patients after surgery, it can cause such undesirable effects as nausea, constipation, respiratory problems, and physical dependence.

This new evidence that OFQ and its receptor may play a role in opioid function may lead to new research exploring balance or homeostasis of the opioid system. If there is an imbalance or overactivity in one part of the brain, a compensatory change usually occurs to counterbalance it. These new findings raise interesting possibilities for developing therapeutic agents that act to compensate for the effects of the OFQ receptor. "Therapeutic drugs designed to block OFQ receptors may allow physicians to use less morphine to relieve pain because the endogenous system opposing morphine's actions would be blocked. We are hoping that an antagonist to the OFQ receptor will make morphine more efficacious so patients could benefit from its pain relieving effects without experiencing the unwanted side effects," Dr. Grandy said. He added that blocking the OFQ receptor may decrease the irritability, anxiety and nausea characteristic of heroin withdrawal.

This work was supported by NIDA, the National Institute on Neurological Diseases and Stroke, and the National Institute on Alcohol Abuse and Alcoholism, all components of the National Institutes of Health. NIDA is the primary Federal agency for the conduct and support of research to increase knowledge and develop strategies to deal with the health problems and issues associated with drug abuse and addiction. NIDA has been supporting the study of opiates since its inception because of their role as the most powerfully effective analgesics.

For additional information on this study and other NIDA research, call the NIDA Press Office at (301) 443-6245. Copies of NIDA Media Advisories and other information are available on the NIDA Home Page at http://www.nida.nih.gov.