Experimental colitis in mice: effects of olsalazine on eicosanoid production in colonic tissue.

In rodents colitis can be induced by adding 2% (w/v) carrageenan (CARR) for 4 weeks or 10% (w/v) dextran sulphate sodium (DSS) for 7 days to their drinking water. These models are suitable to test anti-inflammatory drugs used in inflammatory bowel disease in man. Mice were treated with olsalazine (400 mg/kg body wt) starting 7 days before the DSS or CARR administration. Colonic tissues were incubated with [1-14C]-arachidonic acid and stimulated with A23187 and, thereafter, the pattern of eicosanoids was determined by separation on HPLC. DSS and CARR produced a marked diffuse inflammatory response in the colon and a subsequent 5-fold increase of all eicosanoids after DSS, whereas after CARR only a 2-fold increase of PGs was observed. Olsalazine treatment decreased all cyclooxygenase and lipoxygenase products to baseline levels.