Effect of colchicine on microcrystal-induced prostanoid synthesis by human monocytes. Monocytes were incubated with diluent, MSU crystals (0.6 mg/mL), or CPPD (0.6 mg/mL) for 24 hours, alone or in combination with various concentrations of colchicine (col), or with its inactive analogs, β- and γ-lumicolchicine (L-col), both at a concentration of 10 μmol/L. Cell-free supernatants were collected and analyzed for prostanoid synthesis. The results are the mean ± SD from three separate experiments and are expressed as percent of MSU crystal-stimulated monocytes in the absence of metabolic inhibitor.