In vivo prostaglandin E2 (PGE2) levels were measured in esophageal mucosa excised from 9 normal subjects, 11 patients with gastroesophageal reflux without esophagitis (GER) and 8 patients with reflux esophagitis (RE). Severity of GER was quantified by postcibal pH monitoring. A manometric study was also performed. No difference was found in PGE2 levels between healthy mucosa in controls (41.7 +/- 9.3 ng/g of wet tissue, at 15 cm above the lower esophageal sphincter (LES)) and healthy mucosa in GER (37.8 +/- 11.2 ng/g) or in RE (34.3 +/- 9.0 ng/l). However, PGE2 levels were significantly enhanced within the inflammatory mucosa in RE (290.4 +/- 45.7 ng/g). No difference was found in basal LES pressure between the 3 groups. These results suggest that PGE2 in the esophagus may be involved in pathogenesis of inflammation. Therefore PGE2 might not have the same cytoprotective function as in stomach or duodenum. No correlation was found between PGE2 levels in the esophagitis lesion or basal LES pressure. These data are not consistent with a possible relationship between LES pressure and the PGE2 content of the distal esophagus.