Mice Offer Insight Into New Pain Drugs

ST. LOUIS — St. Louis researchers studying mice said they have found key factors in the body that could lead to making better pain-reducing drugs. Researchers at the Washington University School of Medicine, led by associate professor Dr. Robert Gereau, studied mice that were missing a specific potassium gene that regulates pain messages sent from the spinal cord to the brain. The research advances a previous Harvard University study and will be published Thursday in the journal Neuron. Mice without the so-called Kv4.2 gene were more sensitive to pain than normal mice, the study showed. Researchers said pain medication could target Kv4.2 in humans. "Pain is a really important protective sensations on the human body," Gereau said. "This study shows the possibility of completely new ways to treat pain at two target spots." Gereau said the study shows that Kv4.2 interacts with another pain regulating molecule called ERK (extracellular signal-related kinase). Past research shows that pain can be diminished if ERK activity is dampened. Both are associated with the severe pain one might feel if they burn themselves on an oven. The study used mice that were genetically modified not to have the Kv4.2 gene and a heat source as an indicator of pain. Normal mice that have Kv4.2 could tolerate the heat felt on their paws longer than mice without the potassium channel. Standard pain relieving drugs, such as morphine, work by shutting off pain transmission, Gereau said. Future drugs that act on Kv4.2 and ERK molecules could be more effective, Gereau said, since both are key factors in the regulating pain sensitivity. Such drugs are years away from being developed, he said, but researchers believe new medicines that focus on Kv4.2 could help surgery patients and those with arthritis. Dr. Geoffrey Abbott, an assistant professor at the Weill Medical College at Cornell University, has done research on similar potassium channels related to the heart and the brain. He said drugs have been developed to treat heart problems using the Kv1.5 protein channel. Abbott called the Washington University study "quite novel." "It's very exciting," Abbott said. "Studies like this are usually the beginning of a long road to more research." "Source":[ http://www.chron.com/disp/story.mpl/ap/health/3774388.html].

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