Table 1

%Inhibition of cGMP PDE by sulindac sulfone and its derivatives

cGMP PDE assays were performed with either the entire 100,000 × g supernatant fraction of HT29 colon cancer cells or a partially purified PDE5 peak obtained by DEAE anion exchange chromatography (33) . Both preparations displayed similar IC50s with the known PDE5 inhibitors E4021 and zaprinast (3 nm and 1.5 μm, respectively) and with the compounds listed in the table. Similar results were obtained with extracts of SW480 cells, which contain both PDE2 and PDE5 (data not shown).

Sulindac sulfone113 ± 18 (n = 6)
CP4613.5 ± 3 (n = 2)
CP2480.39 ± 0.08 (n = 8)