A simple method for measuring of intestinal solute transport in mucosal biopsy specimens.

Accurate in vitro measurements of intestinal mucosal solute uptake in humans are often difficult because only small amounts of tissue material are available. We describe a miniaturized everted sleeve method of measuring intestinal solute uptake in endoscopy biopsy samples that combines simplicity, good tissue viability and reproducibility. Biopsies were mounted on a dressmaker needle head stationed immediately over a stirring bar rotating at 1200 rpm. This approach was used to measure taurocholate uptake in sheep and human endoscopy biopsies. Comparison was made to conventional standardized everted sleeve preparations. Na+-dependent uptake rates correlated well among individual sheep (R2 = 0.88, P < 0.05). There was excellent correlation between conventional and biopsy preparations in humans (R2 = 0.98; P < 0.05). The biopsy method overestimated diffusional uptake rates in sheep and humans by two to three fold when compared to conventional everted sleeve preparations. We conclude that this method is valuable to measure Na+-dependent solute uptake rates in biopsy samples from human intestine.