%0 Journal Article
%T Inhibition of chemokine expression in rat inflamed paws by systemic use of the antihyperalgesic oxidized ATP
%A Alessandro Fulgenzi
%A Giacomo Dell'Antonio
%A Chiara Foglieni
%A Elena Cin
%A Paolo Ticozzi
%A Jos¨¨ S Franzone
%A Maria Ferrero
%J BMC Immunology
%D 2005
%I BioMed Central
%R 10.1186/1471-2172-6-18
%X Local, oral or intravenous administration of a single dose of oATP significantly reduced thermal hyperalgesia in hind paws of rats for 24 hours, and such effect was greater than that induced by diclofenac or indomethacin. Following oATP treatment, the expression of the pro-inflammatory chemokines interferon-gamma-inducible protein-10 (IP-10), mon ocyte chemoattractant protein-1 (MCP-1) and interleukin-8 (IL-8) within the inflamed tissues markedly decreased on vessels and infiltrated cells. In parallel, the immunohistochemical findings showed an impairment, with respect to the untreated rats, in P2X7 expression, mainly on nerves and vessels close to the site of inflammation. Finally, oATP treatment significantly reduced the presence of infiltrating inflammatory macrophages in the paw tissue.Taken together these results clearly show that oATP reduces carrageenan-induced inflammation in rats.We previously showed the ability of the local treatment with periodated oxidized ATP (oATP), an inhibitor of the P2X7 ATP (adenosine 5'-triphosphate) receptor [1], to relieve inflammatory pain in the rat paw, in which chronic inflammation was induced by Freund's complete adjuvant (CFA) injection [2,3]. There are two classes of ATP-receptors, the ionotropic P2X receptors and the G-protein-coupled P2Y receptors. Recently, these purinoceptors have been extensively studied because of their important roles in several ATP-mediated cellular functions [4]. In particular, there are seven subunits of P2X receptors (P2X1¨C7), which are differently expressed by many cell types [4]. Some P2X receptors are expressed in DRG neurons [5].ATP, released by neuronal and non-neuronal cells, is able to initiate a pronociceptive signal through different P2X subtypes of P2 purinoceptors [6]. The expression of P2X by subsets of primary afferent neurons plays a role in the generation of pain from the periphery to the spinal cord [7,8]. ATP seems to be involved in the initiation of impulses in some sensory fi
%U http://www.biomedcentral.com/1471-2172/6/18