Background/aims: In our experience with the acute murine dextran sodium sulphate (DSS) model of experimental colitis, we noted both interstrain and interanimal variations in daily water consumption. One might critically question whether observed differences in injuries are just a dose dependency phenomenon reflecting variations in DSS intake. To clarify this important topic, we performed a dose and concentration dependency study of DSS in Balb/c mice. We also determined Th1 and Th2 cytokine levels to compare the cytokine profile to that from inflammatory bowel disease (IBD).
Methods: In four groups (14 animals each group) different concentrations of DSS (0, 2.5, 5 and 7.5%) were given for 7 days ad libitum. Mucosal injury of the entire colon was histologically assessed and graded. Cytokine levels were determined by competitive quantitative RT-PCR.
Results: A linear increase in the crypt damage score was noted with increasing concentrations (0, 4.9 +/- 0.7, 11.9 +/- 0.5 and 18.9 +/- 1.3, respectively), but the total dose of DSS intake did not correlate with mucosal damage. Progressive upregulation in the transcripts for Th1 cytokines (IL-12, IFN-gamma, IL-1, TNF-alpha) was observed with increasing dosage of DSS. Interestingly, an increase in IL-10, but not IL-4 mRNA transcripts was also noted.
Discussion: Acute DSS-induced mucosal injury is dependent on the administered DSS water concentration but not on the consumed DSS dose. The cytokine profile is a classic Th1 response and is similar to that of various inflammatory conditions in the colon.
Conclusions: Minor variations in fluid consumption do not affect the severity of DSS-induced injury in mice. The acute murine DSS colitis model is useful for studying the pathophysiological aspects of colonic inflammatory diseases as IBD and for evaluating new potential therapeutic agents
Copyright 2000 S. Karger AG, Basel