Featured Research

from universities, journals, and other organizations

New Target Identified For Chronic Pain Therapy

Date:
November 22, 1999
Source:
National Institute of Neurological Disorders And Stroke
Summary:
Scientists funded by the National Institute of Neurological Disorders and Stroke (NINDS) may soon be able to reduce sensitivity to stimuli that are associated with chronic neuropathic and inflammatory pain by disabling certain nerve cells that send pain signals to the brain.

Scientists funded by the National Institute of Neurological Disorders and Stroke (NINDS) may soon be able to reduce sensitivity to stimuli that are associated with chronic neuropathic and inflammatory pain by disabling certain nerve cells that send pain signals to the brain.

Related Articles


Research reported in the November 19, 1999, issue of Science shows that, in an animal model, combining substance P with the ribosome-inactivating protein saporin (SAP) will inhibit the pain associated with nerve injury when administered before or after the development of neuropathic pain and will significantly reduce sensitivity to stimuli associated with inflammatory pain. Previous data have suggested that in the peripheral nervous system, neuropathic and inflammatory pain arise from different mechanisms and are conveyed to the spinal cord by distinct groups of primary afferent neurons. Study findings suggest that these different types of pain conditions, which can arise via different mechanisms, may be conveyed to the spinal cord by the same substance P receptor-expressing neurons. Further, the study found that, following substance P-SAP treatment, opiates such as morphine remain a viable therapy for breakthrough pain. This discovery could lead to new treatments for chronic pain and the development of more targeted pain-relieving drug therapy.

Researchers at the University of Minnesota injected a combination of substance P (a neurotransmitter known to stimulate pain receptors) and SAP into the dorsal horn of the spinal cord in rats. Receptors for substance P¾ large molecules found on the surface of spinal cord nerve cells¾ served as portals for the compound’s entry. Within days, the targeted neurons, located in the outer layer of the spinal cord along its entire length, absorbed the compound and were neutralized. Results indicate the substance P-SAP treatment reduced the number of spinal cord neurons that express substance P receptor as well as lessened the pain response to thermal and mechanically induced pain following nerve injury, inflammation, and the long-term effects of pain produced by capsaicin injection. The results appear to be long-lasting and do not affect other nerve cells.

Scientists already know that spinal cord neurons that express substance P receptors play a role in pain, but their specific role in signaling¾ relaying or conveying pain signals¾ is not entirely understood.

Investigators believe that these results suggest that this small group of neurons that express substance P play a critical role in communicating chronic pain information from the spinal cord to the thalamus, the brain’s pain center.

The concept of using specific receptors to introduce therapeutic compounds may pave the way for a new pain therapy. Such compounds might be first introduced through a lumbar puncture, a technique commonly used for collecting spinal fluid. The compounds would then serve to relay information through the spinal cord to the thalamus, thus blocking pain signals.

"These findings are extremely important to the study of peripheral and neuropathic pain and our treatment of persons with persistent pain," says Patrick Mantyh, Ph.D., of the University of Minnesota and the Veterans Affairs Medical Center in Minneapolis, who led the study. "We were able to administer a potential treatment and specifically channel it to certain cells, disabling them. We can now focus on the biology of these cells and look at new ways of silencing these cells in other types of persistent pain."

"This discovery is critically important to our understanding of the pain process," says Cheryl Kitt, Ph.D., program director for pain at the NINDS. "Understanding pain pathway changes at the cellular level offers great potential for more effective treatment for pain."

Scientists now need to perform toxicology studies in large animals to demonstrate the safety and efficacy of this treatment in another species. If these studies are successful, approval would be sought to treat terminally ill patients who have severe chronic pain (cancer pain) to determine the extent of the relief of chronic pain in humans.

The NINDS, part of the National Institutes of Health located in Bethesda, Maryland, is the nation’s leading supporter of research on the brain and nervous system and a lead agency in the Congressionally designated Decade of the Brain. The NINDS celebrates its 50th anniversary in the year 2000.


Story Source:

The above story is based on materials provided by National Institute of Neurological Disorders And Stroke. Note: Materials may be edited for content and length.


Cite This Page:

National Institute of Neurological Disorders And Stroke. "New Target Identified For Chronic Pain Therapy." ScienceDaily. ScienceDaily, 22 November 1999. <www.sciencedaily.com/releases/1999/11/991122081153.htm>.
National Institute of Neurological Disorders And Stroke. (1999, November 22). New Target Identified For Chronic Pain Therapy. ScienceDaily. Retrieved November 29, 2014 from www.sciencedaily.com/releases/1999/11/991122081153.htm
National Institute of Neurological Disorders And Stroke. "New Target Identified For Chronic Pain Therapy." ScienceDaily. www.sciencedaily.com/releases/1999/11/991122081153.htm (accessed November 29, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, November 29, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Rural India's Low-Cost Sanitary Pad Revolution

Rural India's Low-Cost Sanitary Pad Revolution

AFP (Nov. 28, 2014) — One man hopes his invention -– a machine that produces cheap sanitary pads –- will help empower Indian women. Duration: 01:51 Video provided by AFP
Powered by NewsLook.com
Research on Bats Could Help Develop Drugs Against Ebola

Research on Bats Could Help Develop Drugs Against Ebola

AFP (Nov. 28, 2014) — In Africa's only biosafety level 4 laboratory, scientists have been carrying out experiments on bats to understand how virus like Ebola are being transmitted, and how some of them resist to it. Duration: 01:18 Video provided by AFP
Powered by NewsLook.com
WHO Says Male Ebola Survivors Should Abstain From Sex

WHO Says Male Ebola Survivors Should Abstain From Sex

Newsy (Nov. 28, 2014) — WHO cites four studies that say Ebola can still be detected in semen up to 82 days after the onset of symptoms. Video provided by Newsy
Powered by NewsLook.com
Ebola Leaves Orphans Alone in Sierra Leone

Ebola Leaves Orphans Alone in Sierra Leone

AFP (Nov. 27, 2014) — The Ebola epidemic sweeping Sierra Leone is having a profound effect on the country's children, many of whom have been left without any family members to support them. Duration: 01:02 Video provided by AFP
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
 
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:  

Breaking News:

Strange & Offbeat Stories

 

Health & Medicine

Mind & Brain

Living & Well

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:  

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile iPhone Android Web
Follow Facebook Twitter Google+
Subscribe RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins