Electrical measurement of chloride secretion in the perfused human jejunum: effects of theophylline and prostaglandin E1.

The effects of intraluminal theophylline or prostaglandin E1 (PGE1) on transepithelial potential difference (PD) were examined in the human jejunum in vivo with a quadruple lumen perfusion tube. To measure transepithelial PDs, we placed one of the Ag/AgCl electrodes in the jejunal lumen and the other in the subcutaneous region of the left forearm of the subjects. Infusion of theophylline or PGE1 into the jejunal lumen produced a change in the PD, the lumen being more negatively charged. The magnitude of the change in PD for 2.4 X 10(-3) M theophylline was 3.3 +/- 0.48 mV (mean +/- S.E., n = 6) and that for 10(-6) M PGE1 was 5.0 +/- 0.60 mV (n = 6). In addition, the change in the PD induced by simultaneous infusion of both 2.4 X 10(-3) M theophylline and 10(-7) M PGE1 was about twice as large as the sum of those induced by individual infusion of the same concentration of theophylline or PGE1. We concluded that these PD changes occurred primarily by stimulation of electrogenic Cl secretion in the jejunum. Further exploitation of this method to determine PD might be useful for clinical investigation of the intestinal secretion.