|
Academic/Biomedical Research
News & Jobs
|
|
|
|
|
|
|
|
|
|
|
|
|
Free Newsletters
Archive
My Subscriptions
News by Subject
News by Disease
News by Date
PLoS
Search News
Post Your News
JoVE
Job Seeker Login
Most Recent Jobs
Search Jobs
Post Resume
Career Fairs
Career Resources
For Employers
Regional News
US & Canada
Biotech Bay
Biotech Beach
Genetown
Pharm Country
BioCapital
BioMidwest
Bio NC
BioForest
Southern Pharm
BioCanada East
US Device
Europe
Asia
Company Profiles
Research Store
Research Events
Post an Event
Real Estate
Business Opportunities
|
|
|
|
PLoS By Category | Recent
PLoS Articles
|
|
Anesthesiology and Pain Management - Neurological Disorders - Neuroscience - Physiology
|
Local Loperamide Injection Reduces Mechanosensitivity of Rat Cutaneous, Nociceptive C-Fibers
Published:
Wednesday, July 25, 2012
Author:
Matthias Ringkamp et al.
by Matthias Ringkamp, Michael Tal, Timothy V. Hartke, Matthew Wooten, Alvin McKelvy, Brian P. Turnquist, Yun Guan, Richard A. Meyer, Srinivasa N. Raja
Loperamide reverses signs of mechanical hypersensitivity in an animal model of neuropathic pain suggesting that peripheral opioid receptors may be suitable targets for the treatment of neuropathic pain. Since little is known about loperamide effects on the responsiveness of primary afferent nerve fibers, in vivo electrophysiological recordings from unmyelinated afferents innervating the glabrous skin of the hind paw were performed in rats with an L5 spinal nerve lesion or sham surgery. Mechanical threshold and responsiveness to suprathreshold stimulation were tested before and after loperamide (1.25, 2.5 and 5 µg in 10 µl) or vehicle injection into the cutaneous receptive field. Loperamide dose-dependently decreased mechanosensitivity in unmyelinated afferents of nerve-injured and sham animals, and this effect was not blocked by naloxone pretreatment. We then investigated loperamide effects on nerve conduction by recording compound action potentials in vitro during incubation of the sciatic nerve with increasing loperamide concentrations. Loperamide dose-dependently decreased compound action potentials of myelinated and unmyelinated fibers (ED50?=?8 and 4 µg/10 µl, respectively). This blockade was not prevented by pre-incubation with naloxone. These results suggest that loperamide reversal of behavioral signs of neuropathic pain may be mediated, at least in part, by mechanisms independent of opioid receptors, most probably by local anesthetic actions.
More...
|
|
|
 |
|
|
|
|
|
|
|
|