Featured Research

from universities, journals, and other organizations

Transporter Is Possible Target For Safer Pain Medicine

Date:
June 12, 2006
Source:
Medical College of Georgia
Summary:
A transporter that silences one of the body's natural pain killers holds promise for new powerful, non-addictive pain medicines as well as understanding AIDS patients' increased pain perception, researchers say.

Dr. Vadivel Ganapathy, chair of the Department of Biochemistry and Molecular Biology at the Medical College of Georgia.
Credit: Image courtesy of Medical College of Georgia

A transporter that silences one of the body’s natural pain killers holds promise for new powerful, non-addictive pain medicines as well as understanding AIDS patients’ increased pain perception, researchers say.

Opiod peptides are natural pain relievers with receptors – first identified because they react to opium – throughout the body, says Dr. Vadivel Ganapathy, chair of the Department of Biochemistry and Molecular Biology at the Medical College of Georgia. Studies have shown, for example, opiod peptide levels increase during childbirth.

Many potent pain killers, such as morphine and codeine, override this natural pain control system by directly activating opiod peptide receptors. While pain control is effective, it comes at a price: potential addiction, immune suppression and constipation.

Now researchers want to know whether safer pain killers can be developed that augment the body’s natural pain-killing ability by targeting instead the opiod peptide transport system that terminates pain-control communication, says Dr. Ganapathy. “This has the potential for non-addictive pain killers that are effective, but by a different mechanism.”

Many popular antidepressants work in a similar fashion to keep the body’s natural chemical messengers, called neurotransmitters, working longer by keeping them from being taken back up into the neuron by transport systems. Chemical messengers are supposed to have limited action, he says. But depressed patients have insufficient levels of chemicals for adequate communication between neurons. Antidepressants provide more mileage from existing neurotransmitters.

Dr. Ganapathy hopes to do the same with endogenous pain killers. Armed with a two-year, $286,000 grant from the National Institute on Drug Abuse, he is working to clone the opiod peptide transporter he identified three years ago and identify the responsible gene and protein.

Interestingly he also has found mice expressing one of the HIV proteins have increased activity of this transporter, a finding that might help explain why HIV patients have increased pain perception. “That means the normal endogenous activity of this transport system is higher in HIV patients, so natural pain mechanisms are not working that well,” says Dr. Ganapathy.

The National Institute on Drug Abuse asked him to apply for the Cutting Edge Basic Research Grant – which enables quick review for funding of novel ideas – to pursue this hypothesis as well as the molecular analysis of the transporter.

The idea that a transport system is involved is itself a novel concept. Conventional wisdom was that an enzyme was responsible for hydrolyzing, or decomposing, opiod peptide, Dr. Ganapathy says. This is the case for at least one neurotransmitter – acetylcholine, implicated in Alzheimer’s - which is inactivated by an enzyme, rather than being transported back into the neuron like other neurotransmitters, such as serotonin, which has a role in depression.

But when he watched the activity of opiod peptides, he saw it actively taken back up into the neuronal cells.

Cloning the transporter and dissecting its molecular profile will ultimately provide a model for studying whether naturally occurring or designer drugs block this re-uptake. In fact, the National Institute on Drug Abuse will provide Dr. Ganapathy with a number of synthetic opiod peptides to see whether they are substrates, or blockers, of this transport system.

“We know this recognizes peptides. Therefore, any chemical compound that will block the transport function must have some resemblance to its natural substrate. Otherwise, it might not do the job,” Dr. Ganapathy says.

He’s already testing naturally occurring amino acids and peptides and found one – lysine, an essential amino acid vital to good growth and found in high concentrations in red meat, cheeses, poultry, sardines, nuts, eggs and soybeans – that’s a pretty good fit.

“We may be able to take this compound as a starting point, then add a few things to make it more effective. You could have a lysine-based drug for the treatment of pain, maybe even a nutritional supplement to prevent pain,” says Dr. Ganapathy. “You could use such a treatment to block this transport activity for HIV patients as well as other patients to control pain.”


Story Source:

The above story is based on materials provided by Medical College of Georgia. Note: Materials may be edited for content and length.


Cite This Page:

Medical College of Georgia. "Transporter Is Possible Target For Safer Pain Medicine." ScienceDaily. ScienceDaily, 12 June 2006. <www.sciencedaily.com/releases/2006/06/060609121642.htm>.
Medical College of Georgia. (2006, June 12). Transporter Is Possible Target For Safer Pain Medicine. ScienceDaily. Retrieved September 22, 2014 from www.sciencedaily.com/releases/2006/06/060609121642.htm
Medical College of Georgia. "Transporter Is Possible Target For Safer Pain Medicine." ScienceDaily. www.sciencedaily.com/releases/2006/06/060609121642.htm (accessed September 22, 2014).

Share This



More Health & Medicine News

Monday, September 22, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Liberia Pleads for Help to Fight Ebola

Liberia Pleads for Help to Fight Ebola

AP (Sep. 22, 2014) Liberia's finance minister is urging the international community to quickly follow through on pledges of cash to battle Ebola. Bodies are piling up in the capital Monrovia as the nation awaits more help. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Ebola Doctor Says Border Controls Critical

Ebola Doctor Says Border Controls Critical

AP (Sep. 22, 2014) A Florida doctor who helped fight the expanding Ebola outbreak in West Africa says the disease can be stopped, but only if nations quickly step up their response and make border control a priority. (Sept. 22) Video provided by AP
Powered by NewsLook.com
Global Ebola Aid Increasing But Critics Say It's Late

Global Ebola Aid Increasing But Critics Say It's Late

Newsy (Sep. 21, 2014) More than 100 tons of medical supplies were sent to West Africa on Saturday, but aid workers say the global response is still sluggish. Video provided by Newsy
Powered by NewsLook.com
Sierra Leone in Lockdown to Control Ebola

Sierra Leone in Lockdown to Control Ebola

AP (Sep. 21, 2014) Sierra Leone residents remained in lockdown on Saturday as part of a massive effort to confine millions of people to their homes in a bid to stem the biggest Ebola outbreak in history. (Sept. 20) Video provided by AP
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