Breaking News
May 26, 2018 - Most concussion patients do not receive follow-up care after hospital discharge, says study
May 26, 2018 - Lifetime risks of developing Alzheimer’s dementia vary by age, gender
May 26, 2018 - Researchers find novel ways to improve participation in clinical research
May 26, 2018 - Researchers develop methods for measuring free-base nicotine levels in e-cigarettes
May 26, 2018 - AHA: Preterm Birth Could Warn of Mom’s Future Heart Risks
May 26, 2018 - Some calories more harmful than others
May 26, 2018 - Study links cell size with commitment to division
May 26, 2018 - Researchers develop new, rapid blood test to detect liver damage
May 26, 2018 - Researchers discover cascade of immune processes linked to poor outcomes in aggressive breast cancer
May 26, 2018 - New research will use mathematics to solve mysteries in cell biology
May 26, 2018 - Mice remain slim on burger diet
May 26, 2018 - BMC receives $13.5 million award to test methods for delivering childhood anxiety treatment
May 26, 2018 - ‘Right to Try Act’ will not benefit terminally-ill patients
May 26, 2018 - Study reveals novel statistical algorithm to identify potential disease genes
May 26, 2018 - Two genes play vital roles in malignant brain cancer
May 26, 2018 - Study explores link between groundwater lithium and diagnoses of bipolar disorder, dementia
May 26, 2018 - Researchers reveal stimulatory effects of myelin on young neural cells
May 26, 2018 - Small part of cellular protein that helps form long-term memories also drives neurodegeneration
May 26, 2018 - Four-legged friends can have heart issues, too
May 26, 2018 - Scientists create small, self-contained spaces inside mammalian cells
May 26, 2018 - Better Social Support Network Protects Black Men Against HIV
May 26, 2018 - National Heart, Lung, and Blood Institute (NHLBI)
May 26, 2018 - Burnout, depression can affect ophthalmology residents, study finds
May 26, 2018 - Latinos and African Americans more likely to experience serious depression than Whites
May 26, 2018 - Data from past epidemic could help improve response to future Ebola outbreaks
May 26, 2018 - Researchers provide insight into how the memory molecule limits brain plasticity
May 26, 2018 - OSU biologist describes ‘restoration ecology’ approach toward patient health
May 26, 2018 - New approach to study brown fat could aid in finding treatments for obesity
May 26, 2018 - Could More Fish in the Diet Boost Sex Lives and Fertility?
May 26, 2018 - NTU Singapore and SERI invent new scope to diagnose glaucoma
May 26, 2018 - Cancer cells co-opt pain-sensing ‘neural channel’ to increase tolerance against oxidative stress
May 26, 2018 - Study uncovers why pesticide exposure increases Parkinson’s disease risk in some people
May 26, 2018 - Study finds link between lead exposure and fertility rates
May 26, 2018 - Delivery of standardized diabetes care could help achieve equitable health outcomes for all patients
May 26, 2018 - FDA authorizes marketing of OsteoDetect software for detecting wrist fractures
May 26, 2018 - Children and adolescents growing up in extreme societal conditions more likely to resort to violence
May 26, 2018 - New study puts forth most comprehensive tree of life for malaria parasites
May 26, 2018 - UVA researchers establish new guidelines for explorers of the submicroscopic world inside us
May 26, 2018 - Princeton Instruments and C-SOPS announce collaboration on innovative pharmaceutical technology
May 26, 2018 - New research shows why babies need to move in the womb
May 26, 2018 - UK steps forward to tackle global antimicrobial resistance
May 26, 2018 - CRISPR-Cas9-based strategy allows researchers to precisely alter hundreds of different genes
May 26, 2018 - Novoheart announces next generation of ‘Human heart-in-a-jar’ technology for advanced drug discovery
May 26, 2018 - UT Southwestern-led researchers find new way to determine prognosis of invasive kidney cancer
May 26, 2018 - Researchers develop film to prevent bacteria from growing on dental retainers and aligners
May 26, 2018 - Mobile health intervention for people with serious mental illness as effective as clinic-based treatment
May 26, 2018 - Vaginal estradiol tablets outperform moisturizers when treating vulvovaginal problems
May 26, 2018 - Researchers call for new genetic tests for congenital diseases
May 26, 2018 - KHN’s ‘What the Health?’ Campaign promises kept, plus ‘nerd reports’
May 26, 2018 - AARDA collaborates with Allegheny Health Network and new AHN Autoimmunity Institute
May 26, 2018 - Lung-on-a-chip technology could streamline drug-testing for pulmonary fibrosis
May 26, 2018 - Researchers work together to solve mystery of motor neuron death in ALS patients
May 26, 2018 - Study finds early antibiotic initiation for majority of premature infants
May 26, 2018 - New environmental monitoring project finds increased numbers of deer ticks in Southern Indiana
May 26, 2018 - Pediatricians Should Advocate for Life Support Training
May 26, 2018 - Cannabidiol significantly reduces seizures in patients with severe form of epilepsy
May 26, 2018 - Allergies can have serious, far-reaching consequences on adolescents
May 26, 2018 - Scientists develop lab-based system to study mechanisms of common liver disease
May 25, 2018 - New guidelines may help pathologists to more accurately classify and diagnose invasive melanoma
May 25, 2018 - Immune cells promote lung cancer metastases by forming clots in tumors, study finds
May 25, 2018 - Can Excess Weight in Toddlers Cause Brain Drain?
May 25, 2018 - Studying insight
May 25, 2018 - Researchers reveal potent new mechanism of action for treatment of IBD
May 25, 2018 - Study shows lack of follow-up care for patients with concussion
May 25, 2018 - Study establishes the importance of haploid cells
May 25, 2018 - Coveted BMJ award bestowed on The Clatterbridge Cancer Center
May 25, 2018 - AACN outlines evidence-based protocols and clinical strategies to manage alarms
May 25, 2018 - Origami inspires researchers to develop new solution for tissue regeneration
May 25, 2018 - Melorheostosis – Genetics Home Reference
May 25, 2018 - Non-addictive pain medication changing therapy for substance use disorders
May 25, 2018 - Delayed lactate measurements in sepsis patients increase risk of in-hospital death
May 25, 2018 - Researchers identify novel epigenetic mutations as cause of neurodevelopmental, congenital disorders
May 25, 2018 - UD researchers examine connection between DNA replication in HPV and cancer
May 25, 2018 - Researchers identify neurons that play key role in aggressive behavior
May 25, 2018 - Snail’s eye inspires new type of RIOCATH urinary catheter
May 25, 2018 - Russian researchers develop high-tech device-transformer for ultrasound examination
May 25, 2018 - Researchers discover unexpected chemosensor pathway for predator odor-evoked innate fear behaviors
May 25, 2018 - Researchers build 3-D printer that offers sweet solution to making detailed structures
May 25, 2018 - Nearly one in three people know someone addicted to opioids
May 25, 2018 - Research suggests link between faulty gene, alcohol, and heart failure
Targeting opioid receptor offers relief for chronic itching

Targeting opioid receptor offers relief for chronic itching

image_pdfDownload PDFimage_print

A common side effect of opioids is intense itching — a problem for some patients who need the drugs for pain relief and for others fighting addiction.

Now, studying mice, researchers at Washington University School of Medicine in St. Louis have found that a drug called nalfurafine hydrochloride can deliver itch relief by targeting particular opioid receptors on neurons in the spinal cord. The drug (brand name Remitch) is approved in Japan to alleviate itching in dialysis patients with chronic kidney disease and in patients with severe liver disease. The drug also is being tested for its anti-itch effects in the U.S., but until now scientists haven’t understood how it works.

The new study suggests that the drug may be effective against many types of chronic itching that don’t respond to conventional drugs such as antihistamines. The drug targets what’s known as kappa opioid receptors on neurons in the spinal cord. While other opioid receptors on the same neurons can ramp up itching, this study shows that activating the kappa receptor significantly dials down itching.

The findings are published April 17 in the journal Cell Reports.

“The kappa opioid receptors activate a pathway that tamps down the activity of GRPR, which our lab previously identified as the first itch gene,” said senior investigator Zhou-Feng Chen, PhD, director of the Center for the Study of Itch at Washington University School of Medicine in St. Louis. “This gene relays itch signals from the spine to the brain.”

Chen, the Russell D. and Mary B. Shelden Professor of Anesthesiology, and his colleagues studied mice treated with a substance to make them feel itchy. Others had been genetically engineered to develop chronic itching. When the researchers injected the drug directly into the spinal cords of the animals, their scratching was markedly reduced.

Chen’s team found that about half of the neurons in the spinal cord that transmit itch signals have kappa opioid receptors, and when those receptors are activated, they inhibit GRPR.

It may not be practical to administer spinal cord injections of drugs to patients with chronic itch — whatever the cause — but now that the researchers have identified a way to alleviate such itching, they can try to activate the same receptor in other ways. Or, Chen said, they may target some of the downstream molecules that are activated when the kappa receptor is targeted.

“Some molecules downstream from the kappa receptor may still be able to tamp down itching without causing any unwanted side effects that may occur when drugs activate the kappa receptor in parts of the body outside of the spinal cord,” explained Chen, who also is a professor of psychiatry and of developmental biology.

His team is working to learn whether those strategies will work in mice, with the hope that the same molecules eventually may become therapeutic targets in people with chronic itch.

Source:

New clues point to relief for chronic itching

Tagged with:

About author

Related Articles