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:6/25/2016)... CA (PRWEB) , ... June 25, 2016 , ... As ... with Magna Cum Laude and his M.D from the David Geffen School of Medicine ... and returned to Los Angeles to complete his fellowship in hematology/oncology at the UCLA-Olive ...
(Date:6/24/2016)... ... 24, 2016 , ... Those who have experienced traumatic events may suffer from ... avenues, such as drug or alcohol abuse, as a coping mechanism. To avoid this ... coping following a traumatic event. , Trauma sufferers tend to feel a range of ...
(Date:6/24/2016)... ... June 24, 2016 , ... Dr. Amanda Cheng, an ... Dr. Cheng has extensive experience with all areas of orthodontics, including robotic Suresmile ... orthodontics. , Micro-osteoperforation is a revolutionary adjunct to orthodontic treatment. It can ...
(Date:6/24/2016)... ... June 24, 2016 , ... The Haute Beauty Network, ... M. Weintraub as a prominent plastic surgeon and the network’s newest partner. ... the most handsome men, look naturally attractive. Plastic surgery should be invisible.” He ...
(Date:6/24/2016)... MD (PRWEB) , ... June 24, 2016 , ... ... protocols for human induced pluripotent stem (iPS) cells and other difficult to transfect ... G9™ Cloning Medium. The PluriQ™ G9™ Gene Editing System is a ...
Breaking Medicine News(10 mins):
(Date:6/24/2016)... NAMUR , Belgium , ...  (NYSE MKT: VNRX), today announced the appointment of ... Board of Directors as a Non-Executive Director, effective ... the Company,s Audit, Compensation and Nominations and Governance ... Board, Dr. Futcher will provide independent expertise and ...
(Date:6/23/2016)... Research and Markets has announced the ... to 2022" report to their offering. ... patients with kidney failure, it replaces the function of kidneys ... blood and thus the treatment helps to keep the patient ... Increasing number of ESRD patients & substantial ...
(Date:6/23/2016)... June 23, 2016  In a startling report released today, ... residents by lacking a comprehensive, proven plan to eliminate prescription opioid ... ranking of how states are tackling the worst drug crisis in ... states – Kentucky , New Mexico ... . Of the 28 failing states, three – ...
Breaking Medicine Technology: