Figure 5.

(A) Representative experiment showing the effect of indomethacin (+) or NS398 (◊) on the COX activity of mIMCD-3 cells. COX activity was estimated from the rate of appearance of PGE₂ in the medium. Rapidly proliferating mIMCD-3 cells were exposed to indomethacin or NS398 for 4 days. Arachidonic acid (5 μM) was added during the last 24 h. (B) A representative experiment demonstrating the effects of indomethacin or NS398 on the number of rapidly proliferating mIMCD3 cells. The cell number was estimated by MTT assay. Results of at least one experiment for each drug concentration, measuring with MTT, and at least one other experiments measuring with LSC (not shown) were essentially the same. Note that 2 mM NS398 and 50 mM indomethacin do not decrease cell number, despite the complete inhibition of COX.