Oxazolone-induced colitis in rats: effects of budesonide, cyclosporin A, and 5-aminosalicylic acid.
BACKGROUND
The intention of the present study was to develop a new hapten-based inflammatory bowel disease model in the rat, useful for pharmacologic screening of new substances with anti-inflammatory properties and immunomodulating capacities. It was considered important to avoid the use of an irritating barrier breaker, such as ethanol.


METHODS
Dark Agouti rats were skin-sensitized with oxazolone and further challenged intra-rectally with oxazolone dissolved in carmellose sodium (Orabase)/peanut oil. The effects of treatment with budesonide, prednisolone, cyclosporin A, and 5-aminosalicylic acid (5-ASA) were studied.


RESULTS
The intra-rectal challenge with oxazolone in sensitized rats induced an inflammation with an increased colon wet weight, pronounced myeloperoxidase (MPO) activity, and hyperemia/ulcerations in the epithelial lining. Improvement was achieved by treatment with budesonide, prednisolone, and cyclosporin A but not with 5-ASA.


CONCLUSIONS
The model fulfills the criteria for a fast, reproducible animal model for human colon inflammation, suitable for pharmacologic screening and studies of an immune-driven colon inflammation.
Ekström
G M
GM
Dept. of Pharmacology, Preclinical R & D Unit, Astra Draco AB, Lund, Sweden.
D000818:Animals; D019819:Budesonide / Q000627:therapeutic use*; D003092:Colitis / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D003106:Colon / Q000033:anatomy & histology / Q000187:drug effects / Q000201:enzymology; D016572:Cyclosporine / Q000627:therapeutic use*; D004195:Disease Models, Animal; D005260:Female; D007413:Intestinal Mucosa / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D019804:Mesalamine / Q000627:therapeutic use*; D009929:Organ Size; D010081:Oxazolone / Q000009:adverse effects; D009195:Peroxidase / Q000378:metabolism; D051381:Rats; D013997:Time Factors
D010081:Oxazolone; D019804:Mesalamine; D019819:Budesonide; D016572:Cyclosporine; D009195:Peroxidase