Table of Contents
ISRN Pain
Volume 2013 (2013), Article ID 315626, 5 pages
http://dx.doi.org/10.1155/2013/315626
Research Article

Electrophysiological Study of the Antinociception Produced by the Coapplication of (±)-CPP and Propentofylline in Monoarthritic Rats

1Laboratory of Neurobiology, Department of Biology, Faculty of Chemistry and Biology, University of Santiago of Chile, Avenue Libertador B. O'Higgins 3363, Casilla 40, Correo 33, 9170022 Santiago, Chile
2Vice Rectory of Research, Development and Innovation, University of Santiago of Chile, Avenue Libertador B. O'Higgins 3363, Casilla 40, Correo 33, 9170022 Santiago, Chile

Received 27 January 2013; Accepted 15 March 2013

Academic Editors: S. Butler, T. J. Coderre, V. De Novellis, C. Di Lorenzo, and C.-L. Hsieh

Copyright © 2013 Claudio Laurido et al. This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

Abstract

The NMDA receptor is central in the generation and maintenance of chronic pain. This receptor has several sites of modulation. One is the glutamate recognition site that can be blocked by (±)-3-(2-carboxypiperazin-yl)propyl-1-phosphoric acid or (±)-CPP. We investigated whether the effect of glial inhibition produced by propentophylline (PPF) can be enhanced when combined with (±)-CPP. We used Sprague-Dawley rats with experimental monoarthritis, administering intrathecally the ED30 for both drugs (3.97 μg of (±)-CPP and 1.42 μg of PPF), since this combination produces an antinociceptive supra-additive effect when used in mechanical nociception (Randall-Selitto test). The combination of (±)-PPF and CPP produced an antinociceptive effect which was greater than that each drug alone as tested by both the C reflex and windup. We conclude that the antinociceptive effect of the combination of (±)-PPF and CPP possibly generates a supra additive interaction type in monoarthritic rats.