Human lung macrophages were preincubated (30 min, 37°C) with increasing concentrations (0.01–10 μM) of pyrrolidine-1, AZ-1 or Me-Indoxam and then stimulated with 1 μM A23187 (90 min, 37°C). At the of the incubation, supernatants were collected and centrifuged twice (1000 g, 4°C, 5 min). β-Glucuronidase release was determined by a colorimetric technique. The values are expressed as the percentage of the total cellular content determined in cell aliquots lysed with 0.1% Triton X-100. The data are the mean ± SE of three different experiments. § p < 0.01 vs. unstimulated.