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:10/12/2017)... ... October 12, 2017 , ... Asante, a nationally recognized ... have expanded their existing home health joint venture through an agreement, effective October ... a joint venture home health company with Asante, delivering clinically integrated care, for ...
(Date:10/12/2017)... ... October 12, 2017 , ... Dr. Parsa Mohebi, the ... medical article to the newly revamped Cosmetic Town journal section, featuring ... transplant procedure known as Follicular Unit Extraction (FUE). , Dr. Mohebi ...
(Date:10/12/2017)... ... ... Leading pediatric oncology experts at Children’s National Health System will join ... International Society of Paediatric Oncology (SIOP) Oct. 12-15. Chaired by Jeffrey Dome, ... at Children’s National, and Stephen P. Hunger, M.D., Chief of the Division of ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... of Michigan’s 2017 Best and Brightest in Wellness® by Best and Brightest. OnSite ... program on Friday, Oct. 20 from 7:30 a.m. to 2 p.m. at the ...
(Date:10/12/2017)... ... October 12, 2017 , ... ... in property taxes a year. In some states—like New York, New Jersey, Massachusetts, ... contrast, many overseas retirement havens have extremely low property-tax rates, which contributes to ...
Breaking Medicine News(10 mins):
(Date:10/11/2017)... , Oct. 11, 2017  Caris Life Sciences ... on fulfilling the promise of precision medicine, today announced ... joined Caris, Precision Oncology Alliance™ (POA) as its 17 ... centers, the St. Jude Crosson Cancer Institute will help ... the use of tumor profiling, making cancer treatment more ...
(Date:10/10/2017)... Oct. 10, 2017   West Pharmaceutical Services, Inc. ... for injectable drug administration, today shared the results of ... for improving the intradermal administration of polio vaccines. The ... Summit in May 2017 by Dr. Ondrej Mach ... World Health Organization (WHO), and recently published in the ...
(Date:10/4/2017)... 2017  According to the Centers for Disease Control and Prevention (CDC), ... PhysicianOne Urgent Care is helping communities across Massachusetts , ... by offering no-cost* flu shots through the end of the month. ... insurance regulations. ... get a flu shot is by the end of October, according to ...
Breaking Medicine Technology: