Abstract
Sulphasalazine is a potent and selective inhibitor in vitro of prostaglandin 15-hydroxydehydrogenase in rabbit colon (ID5() = 50 μm) and in several other organs of different species, but does not inhibit prostaglandin A-13 reductase or microsomal prostaglandin synthesis from arachidonic acid. It is suggested that this action may underly the therapeutic usefulness of sulphasalazine in ulcerative colitis for the prevention of relapse.