Navigation Links
Itching Not a Less Intense Form of Pain
Date:11/18/2008

Each are regulated by different molecular mechanisms, scientists show

TUESDAY, Nov. 18 (HealthDay News) -- Pain and itching are regulated by different molecular mechanisms, according to a Washington University study that challenges the long-held belief that itching is a less intense version of the body's response to pain.

This finding could prove important in improving treatment of chronic itching and pain.

Zhou-Feng Chen, of Washington University's Pain Center, in St. Louis, and colleagues found that pain signals are not affected in mice bred without an itch gene called gastrin-releasing peptide receptor (GRPR) or when the gene's actions are blocked. When the mice without the GRPR gene were exposed to itchy stimuli, they scratched less than normal mice.

GRPR, previously identified by the same team of researchers, makes a receptor found in a small number of nerve cells in a region of the spinal cord that transmits itch and pain signals, as well as temperature sensation, from the skin to the brain.

"There are two major types of itching," explained Chen, an associate professor of anesthesiology, psychiatry and developmental biology. Histamine-dependent itching is caused by bug bites or allergic reactions and can be treated with antihistamine drugs. Chronic, severe itching often occurs as a side effect of spinal injections of opioid drugs, such as morphine, given to chronic pain patients. This type of itching can't be relieved by antihistamines.

"Most scientists believed that the itching could not be separated from the drug's pain-killing effects," Chen said. But he and his team thought GRPR may be responsible for the itching but involved in the pain response.

"If we inject a GRPR inhibitor and morphine into the mouse spinal cord, the drug still has its normal analgesic effect, but the mice don't scratch. This is very interesting, because it demonstrates that analgesia and itching can be separated. There may be itch-specific genetic pathways in the spinal cord that are not related to pain sensation," Chen said.

Like mice, humans also have GRPR genes, so it may be possible to treat chronic itching in humans using a similar approach.

"Our findings could have important therapeutic implications. More research needs to be done, but it may be possible to relieve itching in patients by blocking GRPR function without affecting the pain pathway," Chen said.

The study was presented Monday at the Society for Neuroscience annual meeting, in Washington, D.C.

More information

The American Academy of Dermatology has more about itching.



-- Robert Preidt



SOURCE: Washington University School of Medicine in St. Louis, news release, Nov. 17, 2008


'/>"/>
Copyright©2008 ScoutNews,LLC.
All rights reserved  

Related medicine news :

1. Walgreens Pays $35 Million, Settles Pharmacist-Whistleblower Qui Tam Drug Switching Allegations
2. Attorney General Corbett Announces $36.7 Million Multi-State Settlement With CVS/Caremark in National Dosage-Switching Investigation
3. CVS, Americas Largest Pharmacy Chain, Pays Nearly $37 Million to Settle Federal and State Generic Drug Switching Charges
4. Playing Catch in Winter Could Save Kids Pitching Arms
5. How pitching changes little leaguers shoulders
6. Switching to MA Coverage Unlikely for Current Beneficiaries With MediGap or Medicare Only
7. Ultra-fast, ultra-intense laser has clean-cut advantage
Post Your Comments:
*Name:
*Comment:
*Email:
Related Image:
Itching Not a Less Intense Form of Pain
(Date:12/7/2016)... San Fernando Valley, CA (PRWEB) , ... December 07, 2016 , ... ... Sculptra can be used in several ways to restore a more youthful appearance to ... doctors , now offer Sculptra, along with a variety of other treatments, to rejuvenate ...
(Date:12/7/2016)... ... ... They are musicians and librarians, fashion designers and fitness instructors, actors, athletes ... and around the nation. What do they have in common? All have been affected ... compelling new photographic exhibit debuting Friday, December 9 at Logan International Airport in Boston. ...
(Date:12/7/2016)... (PRWEB) , ... December 07, 2016 , ... ... financial consultation services from offices located in South Lyon, Dewitt, Williamston, East Lansing, ... a basketball coach who needs treatment for a brain tumor. , Jason Bauer ...
(Date:12/7/2016)... , ... December 07, 2016 , ... One of two ... of the securement tape is painful for her. "This is why the co-inventor and ... heads," she said. , They then created a prototype of the patent-pending AV-AIR, a ...
(Date:12/7/2016)... ... OCTOBER XX, 2016 (PRWEB) (PRWEB) December 07, 2016 , ... ... new study entitled “Canine Filamentous Dermatitis Associated with Borrelia Infection” ... The study was published in the prestigious Journal of Veterinary Science & Medical ...
Breaking Medicine News(10 mins):
(Date:12/7/2016)... -- According to responses from U.S. oncologists that participated in ... with non-small cell lung cancer (NSCLC), treatment decisions are made ... status. The findings of the survey were presented today as ... ) at the 2016 World Conference on Lung Cancer (WCLC) ... survey results revealed an overall high rate of EGFR mutation ...
(Date:12/7/2016)... 7, 2016 Boehringer Ingelheim today announced ... with unresectable malignant pleural mesothelioma (MPM) met its ... presented at the 17 th IASLC World ... , showed nintedanib plus pemetrexed/cisplatin demonstrated a ... with a significantly improved PFS (9.4 vs 5.7 ...
(Date:12/7/2016)... , December 7, 2016 Today, Stock-Callers.com ... (NASDAQ: JAZZ ), Anthera Pharmaceuticals Inc. (NASDAQ: ... ), and AveXis Inc. (NASDAQ: AVXS ). From ... fell roughly 37% to reach a level equal to what ... down by approximately 14% for the year, it has still ...
Breaking Medicine Technology: