JOURNAL HOME CME HOME THIS MONTH PAST ISSUES ETOC COLLECTIONS
AUTHORS REVIEWERS EDITORIAL BOARD FEEDBACK RSS HELP
A&A International Anesthesia Research Society
QUICK SEARCH:   [advanced]


     

This Article
Right arrow Full Text
Right arrow Full Text (PDF)
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a colleague
Right arrow Similar articles in this journal
Right arrow Similar articles in ISI Web of Science
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via ISI Web of Science (1)
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Hwang, J.-H.
Right arrow Articles by Han, S.-M.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Hwang, J.-H.
Right arrow Articles by Han, S.-M.

Anesth Analg 2005;100:461-468
© 2005 International Anesthesia Research Society
doi: 10.1213/01.ANE.0000143561.68417.70

PAIN MEDICINE

Morphine Can Enhance the Antiallodynic Effect of Intrathecal R-PIA in Rats with Nerve Ligation Injury

Jai-Hyun Hwang, MD, Gyu-Sam Hwang, MD, Sung-Kang Cho, MD, and Sung-Min Han, MD

Department of Anesthesia and Pain Medicine, Asan Medical Center, Seoul, Korea

Address correspondence and reprint requests to Jai-Hyun Hwang, MD, Department of Anesthesia and Pain Medicine, University of Ulsan, College of Medicine, Asan Medical Center, 388-1 Pungnap-Dong, Songpa-Gu, Seoul 138-736, Korea. Address e-mail to jhhwang{at}amc.seoul.kr.

Nerve ligation injury may produce a tactile allodynia. Intrathecal adenosine receptor agonists or morphine have an antiallodynic effect. In this study, we examined the effect of intrathecal morphine on the antiallodynic state induced by the adenosine A1 receptor agonist, N6-(2-phenylisopropyl)-adenosine R-(–)isomer (R-PIA), in a rat model of nerve ligation injury. Rats were prepared with ligation of left L5–6 spinal nerves and intrathecal catheter implantation. Tactile allodynia was measured by applying von Frey filaments to the lesioned hindpaw. Thresholds for withdrawal response were assessed. Morphine and R-PIA were administered to obtain the dose-response curve and the 50% effective dose (ED50). Fractions of ED50s were administered concurrently to establish the ED50 of the drug combination. The drug interaction was analyzed using the isobolographic method. Intrathecal 8-cyclopentyl-1,3-dipropylxanthine (DPCPX), an A1 receptor antagonist, and naloxone were administered to examine the reversal of the antiallodynic effect. Side effects were also observed. Intrathecal morphine and R-PIA and their combination produced a dose-dependent antagonism without severe side effects. Intrathecal morphine synergistically enhanced the antiallodynic effect of R-PIA when coadministered. Intrathecal naloxone and DPCPX reversed the maximal antiallodynic effect in the combination group. These results suggest that activation of µ-opioid and A1 receptors at the spinal level is required for the synergistic interaction on tactile allodynia.






Lippincott, Williams & Wilkins Anesthesia & Analgesia® is published for the International Anesthesia Research Society® by Lippincott Williams & Wilkins with the assistance of Stanford University Libraries' HighWire Press®. Copyright 2006 by the International Anesthesia Research Society. Online ISSN: 1526-7598   Print ISSN: 0003-2999 HighWire Press
Copyright © 2005 by the International Anesthesia Research Society.