The effect of dexamethasone treatment on murine colitis.
BACKGROUND
Corticosteroids are used as anti-inflammatory drugs in the treatment of inflammatory bowel disease. We wanted to know whether dexamethasone (DEX) treatment could prevent dextran sulphate sodium (DSS)-induced colitis in mice.


METHODS
Acute colitis was induced after oral administration of 10% DSS for 2 days. Controls received normal tap water. Five days before and during DSS or tap water exposure half the group was treated with 0.06 mg/day DEX, and the other half received saline. After the mice had been killed, macroscopic observation and histologic evaluation were used to determine the degree of colonic inflammation.


RESULTS
The macroscopic score was significantly increased in untreated DSS mice (P < 0.001). The induction of colitis was not prevented by DEX pretreatment (5.9 +/- 0.9 versus 4.2 +/- 0.6; NS). In addition, the macroscopic scores of DEX-treated controls were significantly increased (1.8 +/- 0.2 versus 0.7 +/- 0.2; P = 0.007), which suggests that DEX has a stimulating effect on colitis induction. The histology score was significantly increased in untreated DSS mice compared with controls (P = 0.016). Analogous to the macroscopic scoring results, the histology score of DEX-treated controls was significantly increased compared with untreated controls (P = 0.046).


CONCLUSIONS
Pretreatment with dexamethasone did not prevent the induction of acute DSS colitis, reflected by both aggravated macroscopic and histologic inflammation scores.
van Meeteren
M E
ME
Dept. of Pharmacology, Erasmus University Medical Centre Rotterdam, The Netherlands.
Meijssen
M A
MA
Zijlstra
F J
FJ
D000208:Acute Disease; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000008:administration & dosage / Q000627:therapeutic use*; D003092:Colitis / Q000139:chemically induced / Q000188:drug therapy* / Q000473:pathology; D003907:Dexamethasone / Q000008:administration & dosage / Q000627:therapeutic use*; D016264:Dextran Sulfate; D004195:Disease Models, Animal; D005938:Glucocorticoids / Q000627:therapeutic use*; D051379:Mice; D008807:Mice, Inbred BALB C
D000893:Anti-Inflammatory Agents; D005938:Glucocorticoids; D003907:Dexamethasone; D016264:Dextran Sulfate