Résumé
Objective To explore the role of lysophosphatidic acid receptor 1(LPA1), which mediates neuropathic pain, in LPA-induced pruritus in mice. Methods We applied real-time PCR to examine the relative LPA1-LPA6 mRNA level, immuno-staining to observe the co-expression of LPA1 with the gastrin-releasing peptide (GRP) in the neurons of dorsal root ganglia (DRG) of mice. "Cheek model" was used to count the scratching after intradermal injection of LPA in mice treated with the LPA1 and LPA3 receptor antagonists Ki16425. Results LPA1 mRNA was found highly expressed in the peripheral sensory neurons; LPA1 co-existed with GRP in the small-or medium-neurons of DRG of mice; an intradermal injection of LPA in mouse cheek produced pain-like wiping, but the pain response was significantly decreased after inhibition of LPA1 receptor with Ki16425(P<0.01), and itch-like scratching behavior was significantly increased (P<0.05). Conclusion These results suggest that down-regulation of LPA1 might lead to scratching behavior in mice treated with LPA.