The effect of Escherichia coli heat-stable toxin on the trans-epithelial intestinal elimination of ciprofloxacin in the rabbit

The effect of Escherichia coli heat-stable toxin (ST) on the intestinal trans-epithelial elimination of ciprofloxacin was studied in the rabbit model. Following a systemic 27 mg/kg dose, excreted amounts of ciprofloxacin during the 2 h experiment were: 9.3 (+/- 4.8); 12.5 (+/- 5.2) and 0.3 (+/- 0.1) microg/cm(2) surface of intestinal wall in ST-challenged jejunal, ileal and caecal loops, respectively. In control loops the corresponding amounts were: 5.0 (+/- 2.8), 6.5 (+/- 3.4) and 0.3 (+/- 0.1) microg/cm(2), respectively. The trans-epithelial elimination of ciprofloxacin was significantly higher in ST-challenged small bowel loops than in controls while caecal elimination was negligible.

Trans-epithelial intestinal elimination of moxifloxacin in rabbits

The intestinal trans-epithelial elimination of moxifloxacin was measured in the jejunum, ileum, caecum and in the bile in a rabbit model. Over a 120 min period following a single parenteral administration of moxifloxacin 15 mg/kg, peak serum concentration was 3.1 (+/- 1.1) mg/L. The elimination constants were: 0.019 (+/- 0. 017) microg/cm(2)/min, 0.011 (+/- 0.014) microg/cm(2)/min and 0.002 (+/- 0.002) microg/cm(2)/min in the jejunum, ileum and caecum, respectively. Per loop, over 120 min, the respective eliminated quantities were: 9.59 (+/- 9.37) microg, 8.26 (+/- 6.74) microg and 1.92 (+/- 1.86) microg. Biliary moxifloxacin concentrations varied between 1.30 and 5.16 mg/L and exceeded serum levels from 45 min onwards. Intestinal concentrations paralleled serum moxifloxacin levels. Altogether, approximately 4.5% of the moxifloxacin dose was eliminated trans-epithelially in the digestive tract over the 120 min experimental period.

Effect of cholera toxin on intestinal elimination of ciprofloxacin in rabbits

The transepithelial intestinal elimination of ciprofloxacin (CPX) was studied in cholera toxin (CT)-challenged and control intestinal loops in the rabbit. CPX concentrations were similar in CT-challenged and control jejunal and ileal loops, while cecal elimination was negligible. The quantities of eliminated CPX per square centimeter of bowel wall were significantly higher in the small intestine CT-challenged loops. The mechanism of elimination of CPX in the small intestine is therefore mainly passive diffusion.