Procoagulant and prothrombotic responses of human endothelium to indomethacin and endotoxin in vitro. Relevance to non-steroidal anti-inflammatory drug enteropathy.

Background: In view of the association between non-steroidal anti-inflammatory drugs (NSAIDs) and microvascular injury in the intestine, this study investigated the procoagulant changes in cultured human umbilical vein endothelial cells (HUVEC) when exposed to indomethacin either alone or in the presence of bacterial lipopolysaccharide (LPS). Methods: Confluent HUVEC cultures were cultured for 1, 6, 12, and 24 h in the presence of LPS (10 μg/ml) with or without indomethacin (1-100 μM). After incubation, supernatants were analysed for 6-keto-prostaglandin (PG) F1α and PGE2 content, whereas cells were freeze-fractured and assayed in a one-stage clotting assay for the expression of procoagulant activity (PCA). Results: LPS induced a significant expression of PCA at 6, 12, and 24 h, with a significantly increased production of 6-keto-PGF1α, whereas the increased PGE2 production was much less pronounced. Indomethacin alone induced a time-dependent PCA response; when coincubated with LPS the PCA response was gr...