Source of group II phospholipase A2 in gastric juice

Gastric juice contains both pancreatic group I phospholipase A2 (PLA2-I) and synovial-type group II phospholipase A2 (PLA2-II), which may play a crucial role in Helicobacter pylori infection and gastric mucosal injury. PLA2-I present in gastric juice is derived from pancreatic acinar cells. The cellular source of PLA2-II found in gastric juice is unknown. A specific cell type of the intestinal mucosa, the Paneth cell, is known to secrete PLA2-II. The purpose of the present study was to define the source of PLA2-II present in gastric juice. For this purpose, gastric juice was collected from 29 individuals during gastroscopy, and mucosal biopsies were taken from the antrum and body of the stomach and from the duodenum as well as from the jejunum of individuals with resected stomach, for immunohistochemical detection of PLA2-II. The concentration of bilirubin in the gastric juice samples was determined to identify duodenogastric regurgitation. The PLA2-II content was significantly higher in bilirubin-positive than in bilirubin-negative gastric juice samples. PLA2-II was localized by immunohistochemistry in Paneth cells in three patients with areas of intestinal metaplasia of the gastric mucosa and in Paneth cells of duodenal and jejunal mucosa in all patients, but not in any other epithelial cell type of the mucosa of the stomach or the small intestine. Inflammatory cells did not contain PLA2-II. The current results suggest that PLA2-II found in gastric juice is derived from the Paneth cells of the small intestinal mucosa.