Kawabata Atsufumi, Kawao Naoyuki, Kuroda Ryotaro, Itoh Hideki, Nishikawa Hiroyuki
Department of Pathophysiology and Therapeutics, School of Pharmaceutical Sciences, Kinki University, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan.
Neuroreport. 2002 Mar 25;13(4):511-4. doi: 10.1097/00001756-200203250-00031.
Protease-activated receptor-2 (PAR-2) in the sensory neurons may be involved in nociceptive processing. We attempted to detect and characterize specific expression of spinal Fos, a marker of nociception, in mast cell-depleted rats. Intraplantar (i.pl.) administration of not only the PAR-2 agonist SLIGRL-NH2, but also the control peptide LSIGRL-NH2, induced Fos expression in naive rats, whereas only the former specifically produced Fos expression in mast cell-depleted rats. This Fos expression was blocked by intrathecal DAMGO, a mu-opioid agonist, and, in part, by i.pl. calphostin C, a protein kinase C (PKC) inhibitor. Thus, specific expression of spinal Fos following peripheral PAR-2 activation is detectable in mast cell-depleted rats, suggesting activation of spinal nociceptive neurons, which is partially mediated by activation of PKC.
