FIGURE 8.

Potentiation by ABC of the effects of ATP on PMN-endothelial cell interactions, the expression of CD11b and on calcium influx. HUVEC and PMN were treated (4 h) with ATP (0.001–20 µmol/L) in the presence or absence of ABC (1 µmol/L) and PMN rolling flux (A) was analyzed. Doses of ABC (1 µmol/L) and ATP (0.1 µmol/L) were selected to treat individually or in combination both PMN and HUVEC or whole blood. In some cases, both HUVEC and PMN or whole blood were pretreated with A804598 (A80, P2X7R antagonist, 1 μmol/L, 30 min) prior to ABC (1 µmol/L) and ATP (0.1 µmol/L). PMN rolling flux (B) was quantified after assembling the flow chamber and the expression of one of the two subunits of Mac-1 CD11b (C) on neutrophils was quantified by flow cytometry. (D) PMNs were treated (1 h) with Polymyxin B (Pol. 8 µmol/L), ABC (1 µmol/L) and ATP (0.1 µmol/L) individually or in combination and, in somes cases, PMN were pretreated with A804598 (A80, P2X7R antagonist, 1 μmol/L, 30 min) prior to Polymyxin B (Pol. 8 µmol/L) and ATP (0.1 µmol/L) or ABC (1 µmol/L) and ATP (0.1 µmol/L). Calcium mobilization was quantified by flow cytometry. Fluorescence values are expressed as a percentage of mean fluorescence intensities of control cells (dotted line). Results are mean ± SEM, Veh: n ≥ 5, Pol. 8: n = 3, ABC 1: n ≥ 5, ATP 0.1: n ≥ 5, ABC 1 + ATP 0.1: n ≥ 5, ABC 1 + ATP 0.1 + A80: n ≥ 5, ABC 1 + ATP 0.1 + Gap¹⁹: n ≥ 3 Pol. 8 + ATP 0.1: n = 3, Pol. 8 + ATP 0.1 + A80: n ≥ 3. *p < 0.05, **p < 0.01 or ***p < 0.001 vs. corresponding value in ABC-treated group. #p < 0.05, ##p < 0.01 or ###p < 0.001 vs. corresponding value in ATP-treated group. +p < 0.05 or ++p < 0.01 vs. corresponding value in the ABC + ATP-treated group (ANOVA followed by Newman-Keuls test).