N-(3-pyridyl)-indomethacin amide (N-3PyIA) is one of several aromatic amides of indomethacin reported to be potent and selective reversible inhibitors of COX-2. N-3PyIA selectively inhibits human recombinant COX-2 with an IC50 of 0.052 μM. It is about 1,300 times less potent as an inhibitor of ovine recombinant COX-1. However, N-3PyIA is not selective as an inhibitor of ovine seminal vesicular COX-1 and ovine placental COX-2. The IC50 values for ovine COX-1 and -2 are 75 and 50 μM, respectively.
