Prostaglandin catabolism and ulcerative colitis: effect of sulphasalazine, 5-aminosalicylic acid and other drugs

1. Evidence is presented for the occurrence of type 1 prostaglandin 15-hidroxydehydrogenase in human rectal mucosa. No evidence of the presence of type 2 dnzyme was found. 2. A 15-keto-prostaglandin reductase, responsible for the breakdown of 13, 14-dihydro 15-keto prostaglandins to 13, 14-dihydro prostaglandins, was also present in human rectal mucosa. 3. Ulcerative colitis patients catabolized prostaglandins to the same extent as the control group. PGE was catabolized significantly better than PGF2 alfa. 4. 5-Aminosalicylic acid and sulphapyridine did not affect prostaglandin catabolism. Sulphasalazine, methilsulphasalazine, indomethacin, flurbiprofen, disodium cromoglycate, sodium salicylate and carbenoxolone sodium inhibited prostaglandin catabolism to the same extent in both groups.Salicylazosulphadimidine was a more potent inhibitor of PGE1 catabolism than of PGF2alfa. 5. The increased prostaglandin synthesis reported for ulcerative colitis patients was not paralleled by increased catabolism, a fact possibly contributing to the accumulation of such compounds in the diseased state

The effect of sulphasalazine on the in vitro activation of human peripheral blood mononuclear cells by phytohemagglutinin P

The in vitro action of sulphaslazine, BW 755-C and indomethacin on phytohemaglutinin P-induced human peripheral brood mononuclear cell activation was studied. Sulphasalazine increased, while indomethacin and BW 755-C decreased, prostaglandin E2 (PGE2) accumulation in activated cultures. When used together with indomethacin or BW 755-C, sulpjasalazine did not counteract the inhibiton of PGE2 caused by the other two. Sulphasalazine inhibited phytohemagglutinin P-induced cell activation in a concentration-dependent manner even when used together with indomethacin or BW 755-C. BW 755-C inhibited cell activation at 350 micronM, wehreas at 11, whereas at 11 micronM only increased sulphasalazine-induced inhibition. The implications of these findings on the etiopathology of inflammatory bowel disease are discussed