NSAIDs induce the shedding of L-selectin in neutrophils by a PKC-independent mechanism.

Effect of the PKC inhibitor Ro 31-8220 on the down-regulation of L-selectin induced by NSAIDs. Neutrophils were preincubated in medium alone (−Ro 31-8220) or in the presence of Ro 31-8220 2 μmol/L. After 15 minutes at room temperature, cells were treated with PMA, flufenamic acid, and aspirin at the concentrations and conditions indicated in Figure 1. The expression of L-selectin was estimated by flow cytometry as described in “Materials and methods.” Shaded histograms represent the L-selectin expression; the dotted line is the negative control of immunostaining (fluorescence produced by the supernatant of P3X63 myeloma). One representative experiment of 3 is shown.