Decreased esophageal peristaltic amplitude in response to prostaglandin E1 and prostacyclin in the baboon.

Prostaglandins have been shown to produce significant decreases in lower esophageal sphincter pressure (LESP), although their effect on esophageal peristalsis is unknown. We studied the effect of infusion of prostaglandin E1 (PGE1) or prostacyclin (PI) on esophageal peristalsis in the proximal and distal esophagus in the awake baboon. Peristalsis was recorded using a polyvinyl catheter and a pneumohydraulic perfusion system and was induced by wet swallows. PGE1 infusion significantly (P less than 0.01) diminished peristaltic amplitude in proximal and distal esophagus by 51% and 77%, respectively. The wave duration was significantly (P less than 0.001) shortened by PGE1 in the distal esophagus, but not in the proximal esophagus. Similarly, prostacyclin significantly (P less than 0.05) decreased peristaltic amplitude in proximal and distal esophagus by 31% and 67%, respectively. As seen with PGE1, PI decreased distal esophageal amplitude significantly (P less than 0.02) more than proximal esophageal amplitude. Equivalent decreases in mean arterial blood pressure seen during prostaglandin infusion were reproduced by bleeding with no changes in measurements of peristaltic activity. Decreased peristaltic wave amplitude and duration suggest that prostaglandins exert a modulating local effect on esophageal muscle. In addition, this effect appears to be more pronounced on distal smooth muscle than on proximal striated muscle in the baboon esophagus.