Lower esophageal sphincter response to pentagastrin in chagasic patients with megaesophagus and megacolon

Abstract

Intraluminal manometric studies were performed in 14 chagasic patients with megaesophagus, 10 chagasic patients with megacolon, and 15 control subjects. Basal lower esophageal sphincter pressure was 20.27±1.16 mmHg (mean±SEM) in controls as compared with 15.16±1.53 mmHg in chagasics with megaesophagus and 14.38±1.50 mmHg in chagasics with megacolon. Dose-response studies to intravenous pentagastrin showed that the chagasic patients exhibited a lower sensitivity to the stimulant than did the controls, as demonstrated by shifting of the dose-response curve to the right and higher individual values of the dose for half maximal contraction (D50). No difference was noted between the calculated maximal contraction (Vmax) of esophageal sphincter of controls and chagasics. These data are compatible with the hypothesis of an interaction between pentagastrin and cholinergic nervous excitation on esophageal sphincteric smooth muscle.