Effect of the C-terminus of murine S100A9 protein on experimental nociception.

Calcium-binding protein S100A9 induces antinociception in mice evaluated by the writhing test. Similarly, a peptide identical to the C-terminus of murine S100A9 (mS100A9p) inhibits the hyperalgesia induced by jararhagin, a metalloprotease. Thus, we investigated the effect of mS100A9p on different models used to evaluate nociception. mS100A9p induced a dose-dependent inhibitory effect on the writhing test, and on mechanical hyperalgesia induced by carrageenan. mS100A9p inhibited thermal hyperalgesia induced by carrageenan. mS100A9p did not modify the nociceptive response in hot plate or tail-flick tests. These data demonstrate that the C-terminus of S100A9 protein interferes with control mechanisms of inflammatory pain.