|
|
||||||||
Department of Neuroscience and Cell Biology, The University of Texas Medical Branch, Galveston, Texas 77555-1069
Submitted 2 April 2004; accepted in final form 9 June 2004
Calcitonin gene-related peptide (CGRP), acting through CGRP receptors, produces behavioral signs of mechanical hyperalgesia in rats and sensitization of wide dynamic range (WDR) neurons in the spinal cord dorsal horn. Although involvement of CGRP receptors in central sensitization has been confirmed, the second-messenger systems activated by CGRP receptor stimulation and involved in pain transmission are not clear. This study tested whether the hyperalgesia and sensitizing effects of CGRP receptor activation on WDR neurons are mediated by protein kinase A or C (PKA or PKC) signaling. Intrathecal injection of CGRP in rats produced mechanical hyperalgesia, as shown by paw withdrawal threshold tests. CGRP-induced hyperalgesia was attenuated significantly by the CGRP1 receptor antagonist, CGRP837. The effect was also attenuated significantly by a PKA inhibitor (H89) or a PKC inhibitor (chelerythrine chloride). Electrophysiological experiments demonstrated that superfusion of the spinal cord with CGRP-induced sensitization of spinal dorsal horn neurons. The CGRP effect could be blocked by CGRP837. Either a PKA or PKC inhibitor (H89 or chelerythrine) also attenuated this effect of CGRP. These results are consistent with the hypothesis that CGRP produces hyperalgesia by a direct action on CGRP1 receptors in the spinal cord dorsal horn and suggest that the effects of CGRP are mediated by both PKA and PKC second-messenger pathways.
This article has been cited by other articles:
![]() |
Y. V. Medvedeva, M.-S. Kim, and Y. M. Usachev Mechanisms of Prolonged Presynaptic Ca2+ Signaling and Glutamate Release Induced by TRPV1 Activation in Rat Sensory Neurons J. Neurosci., May 14, 2008; 28(20): 5295 - 5311. [Abstract] [Full Text] [PDF] |
||||
![]() |
M. A. Davis, D. Hinerfeld, S. Joseph, Y.-H. Hui, N. H. Huang, J. Leszyk, J. Rutherford-Bethard, and S. W. Tam Proteomic Analysis of Rat Liver Phosphoproteins after Treatment with Protein Kinase Inhibitor H89 (N-(2-[p-Bromocinnamylamino-]ethyl)-5-isoquinolinesulfonamide) J. Pharmacol. Exp. Ther., August 1, 2006; 318(2): 589 - 595. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. Li, J. A. McRoberts, H. S. Ennes, M. Trevisani, P. Nicoletti, Y. Mittal, and E. A. Mayer Experimental colitis modulates the functional properties of NMDA receptors in dorsal root ganglia neurons Am J Physiol Gastrointest Liver Physiol, August 1, 2006; 291(2): G219 - G228. [Abstract] [Full Text] [PDF] |
||||
![]() |
J. S. Mogil, F. Miermeister, F. Seifert, K. Strasburg, K. Zimmermann, H. Reinold, J.-S. Austin, N. Bernardini, E. J. Chesler, H. A. Hofmann, et al. Variable sensitivity to noxious heat is mediated by differential expression of the CGRP gene PNAS, September 6, 2005; 102(36): 12938 - 12943. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |
| Visit Other APS Journals Online |