PROSTAGLANDIN PRODUCTION BY HUMAN PERIPHERAL-BLOOD MONOCYTES CHANGES WITH IN-VITRO DIFFERENTIATION

To investigate the influence of in vitro culture on prostaglandin (PG) production, human monocyte-enriched peripheral blood mononuclear cell s were isolated and incubated on gelatin-coated plates. On days zero, five and eleven of culture, the cells were examined microscopically an d the production of PGF(2 alpha), PGE(2), PGD(2), F metabolite (PGFM) and E metabolite (PGEM) were measured by radioimmunoassay. Differences in PG output were analyzed using the Wilcoxon and Friedman tests. Fre shly isolated human peripheral blood monocytes produced mainly PGE(2). In vitro, however, PGE(2) production decreased from 196 (48-288) fmol /10(6) cells per 3h on day zero of culture to 28 (6-51) on day eleven (p=0.04); median (range), n=7. Prostaglandin D-2 and PGEM output decre ased similarly, but these differences failed to reach significance. Pr ostaglandin F-2 alpha and PGFM output, on the other hand, increased fr om 32 and 19 fmol/10(6) cells per 3h, respectively, on day zero of cul ture to 127 (p<0.05) and 58 (p=0.01) on day eleven. Changes in PG outp ut were associated with in vitro differentiation as evidenced by chang es in cellular morphology. These result suggest that differentiation o f human peripheral blood monocytes in vitro is accompanied by a shift in PG output from PGE(2) and PGD(2) towards PGF(2 alpha).