X-ray microanalysis of intestinal chloride transport in vitro and in vivo

Chloride secretion from crypt cells in mouse duodenum or jejunum was investigated in in vivo and in vitro models by electron probe X-ray microanalysis. IBMX-induced chloride secretion could not be demonstrated in vivo, presumably because of competing systemic effects. However, chloride secretion could be induced by 300 microM IBMX in vitro. The best results were obtained under the following conditions: a long preincubation of the tissue slices in high potassium or saline buffer (preferably in high potassium buffer), oxygenated with 95% O(2) and 5% CO(2), at low temperature (4 degrees C), followed by IBMX stimulation in saline buffer at 37 degrees C. Chloride efflux was accompanied by efflux of Na and K.