Human neutrophils as a source of nociceptin: a novel link between pain and inflammation.

Nociceptin is a neuropeptide sharing sequence homology with classical opioid peptides but with a distinct pharmacological profile. Through activation of its receptor, NociR, nociceptin has been linked with several physiological functions in the central nervous system including memory, locomotion, and processing of pain signals. Recently, peripheral blood neutrophils (PMNs) were demonstrated to express a functional NociR, a result suggesting that additional functions of the neuropeptide remain to be elucidated.

Adenosine up-regulates cyclooxygenase-2 in human granulocytes: impact on the balance of eicosanoid generation.

Polymorphonuclear neutrophils (granulocytes; PMNs) are often the first blood cells to migrate toward inflammatory lesions to perform host defense functions. PMNs respond to specific stimuli by releasing several factors and generate lipid mediators of inflammation from the 5-lipoxygenase and the inducible cyclooxygenase (COX)-2 pathways. In view of adenosine's anti-inflammatory properties and suppressive impact on the 5-lipoxygenase pathway, we addressed in this study the impact of this autacoid on the COX-2 pathway.