RESUMEN
The aim of this study was to assess whether colitis induced by dextran sulfate sodium (DSS; 10% in tap water for 7 days) in BALB/c mice is associated with changes in intestinal blood flow. After anaesthesia, systemic hemodynamic variable and regional blood flows and resistances in various organs were measured in both control and DSS-treated mice. Mean arterial blood pressure was significantly lower in DSS-treated mice than in controls (56 +/- 4 vs 66 +/- 3 mm Hg; P < 0.05), but no differences were found in regional blood flows to or vascular resistances in the lungs, liver, stomach, small intestine (upper, middle, and lower part), cecum, mesentery + pancreas, spleen, kidneys, brain, and skin. However, compared to the control mice, blood flows in the middle (0.88 +/- 0.13 vs 0.55 +/- 0.09 ml/min/g; P < 0.05) and distal (0.69 +/- 0.11 vs 0.29 +/- 0.05 ml/min/g; P < 0.05) colon were significantly higher, and vascular resistances in the proximal (0.87 +/- 0.21 vs 1.36 +/- 0.21 mm Hg min/ml/100 g; P < 0.05), middle (0.60 +/- 0.10 vs 1.46 +/- 0.35 mm Hg min/ml 100 g; P < 0.05) as well as distal (0.90 +/- 0.25 vs 2.67 +/- 0.49 mm Hg min/ml/100 g; P < 0.05) colon were significantly lower in mice with experimental colitis. Interestingly, there was a gradient in the intestinal blood flow in control mice from the upper small intestine (2.79 +/- 0.72 ml/min/g) down to the distal colon (0.29 +/- 0.05 ml/min/g); such a gradient was also present in the colitis mice. It is concluded that DSS-induced colitis in mice is associated with microcirculatory disturbances in the colon, mainly in its middle and distal parts.