Direct measurement by pH-microelectrode of the pH microclimate in rat proximal jejunum

摘要: The existence of a region low pH juxtaposed to the proximal jejunum has been proposed explain anomalies in transfer weakly-ionizing substances: yet no direct evidence for this layer exists. Surface electrode studies on everted sacs revealed and estimated be at least 5.5 when buffer is 7.2. With 60 $\mu $m long tip microelectrodes, value 6.0 was obtained, however, dimensions microclimate are uncertain. Optical experiments with pH-indicators using microscope 20 resolving power flat strips vitro, failed detect layer. microelectrode known, values given maximum possible corresponding depth. significance malabsorption briefly discussed.