Vol. 280, Issue 2, 1075-1084, 1997

Effects of Cyclosporine or FK506 in Chronic Colitis¹

Satoshi Aiko, Elaine M. Conner, John A. Fuseler and Matthew B. Grisham

Department of Physiology and Biophysics, Louisiana State University Medical Center, Shreveport, Louisiana

The objective of this study was to quantitatively characterize the effects FK506 on the pathophysiology observed in a model of chronic granulomatous colitis in rats and compare these effects to those obtained with cyclosporin A (CyA). Chronic granulomatous colitis was induced in female Lewis rats via intramural (subserosal) injections of peptidoglycan/polysaccharide (PG/PS) into the distal colon. Rats then received daily injections (i.m.) of either vehicle for CyA (0.5 ml/kg cremophor), CyA in vehicle (25 mg/kg), saline (0.5 ml/kg) or FK506 (1 mg/kg in saline), beginning 7 days after PG/PS injection and continuing for an additional 2 weeks. On day 21, we found that the intramural injection of PG/PS produced a chronic colitis that was associated with hepatic and splenic granulomatous inflammation. Daily treatment with CyA or FK506 beginning 7 days after the induction of colitis resulted in significant inhibition in colonic mucosal permeability, colonic myeloperoxidase activity and plasma nitrate/nitrite levels when compared with their vehicle or untreated controls. In some instances, we noticed a significant vehicle-dependent anti-inflammatory activity. The incidence of peritoneal adhesions as well as the presence of hepatic and splenic granulomas induced by PG/PS were also significantly reduced in both the CyA- and FK506-treated groups. Taken together, these data suggest that immunosuppressive therapy is effective at attenuating both the colitis as well as the extraintestinal inflammation induced by PG/PS. We conclude that FK506 may be useful in the treatment of certain types of inflammatory bowel disease.