Sensitivity of the parietal cell to pentagastrin in health and duodenal ulcer disease: a reappraisal.

In view of the conflicting results on whether pentagastrin sensitivity is genuinely increased in duodenal ulcer (DU) patients, the pentagastrin-gastric acid relationship was restudied in 17 normal subjects and 15 DU patients. In a reproducibility study performed on nine healthy subjects the mean pentagastrin responses obtained on 2 different study days, using a step technique (range, 0.025-6.4 micrograms kg-1h-1), were congruent at each of the five measuring points. Analysis of variance revealed no significant overall differences. However, ED50 values showed a large within- and between-subject variation and failed to correlate significantly, this because a plateau response was not regularly obtained with the top dose. Consequently, ED50 values in normal subjects and DU patients showed a large scatter and were not significantly different, although the potency ratio calculated from the linear parts of the respective dose-response curves was significantly different (2.6; 95% confidence limits, 1.8-3.9). This study thus supplies further evidence that the parietal cell of DU patients has a higher sensitivity to pentagastrin and demonstrates that the reliability of individual ED50 estimations obtained in pentagastrin dose-response studied should not be overrated.