Background: It has been suggested that group II phospholipase A2 (PLA2-II) plays an essential role in inflammation, but the cellular source(s) of the enzyme is (are) largely unknown.
Experimental design: Expression of PLA2-II was analyzed in human gastrointestinal tract at both protein and mRNA levels. Both normal tissues and specimen from patients with a few different common gastrointestinal disorders were analyzed.
Results: Expression of PLA2-II mRNA was seen in the Paneth cells but not in any other cell type of the intestinal tract. Blood vessel walls showed PLA2-II immunoreactivity but were negative in in situ hybridization for PLA2-II mRNA.
Conclusions: It was concluded that nonpancreatic group II PLA2 is synthesized and stored by Paneth cells, whereas other cell types of the gastrointestinal tract seem incapable of synthesis of this enzyme. The positive immunoreaction in vascular structures may reflect the entry of circulating PLA2-II into vessel walls rather than local production of the enzyme.