title: Endotoxin elicits nitric oxide release in rat but prostacyclin synthesis in human and bovine vascular smooth muscle cells.
abstract: Lipopolysaccharide (LPS) exposure to cells and tissues can mimic the biochemical events leading to septic shock. Previous data demonstrated a massive upregulation of prostaglandin endoperoxide H2 synthase (PGHS-2), but not NO synthase-2 (NOS-2) in bovine smooth muscle cells (SMC) between 2 and 12 h of LPS exposure. This caused an abundant release of prostacyclin (PGI2) by constitutive PGI2-synthase as a counterregulation to a dysfunctional endothelium. We here report that human as well as bovine SMC mainly respond by the induction of PGHS-2 and the subsequent release of PGI2, whereas rat SMC exhibited a distinct induction of NOS-2 and released significantly higher amounts of *NO compared with cattle and human. The induction of either PGHS-2 or NOS-2 in the three different species investigated seems to be mutually exclusive in the time window of 2-24 h. This finding should be considered in the setup of experimental models for the investigation of septic shock.
authors.affiliation: Department of Biology, University of Konstanz, 78457 Constance, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Schildknecht
authors.forename: Markus
authors.initials: M
authors.lastname: Bachschmid
authors.forename: Klaus
authors.initials: K
authors.lastname: Weber
authors.forename: Dierk
authors.initials: D
authors.lastname: Maass
authors.forename: Volker
authors.initials: V
authors.lastname: Ullrich
mesh_terms: D000818:Animals; D002417:Cattle; D002478:Cells, Cultured; D051546:Cyclooxygenase 2; D004731:Endotoxins / Q000494:pharmacology*; D011464:Epoprostenol / Q000096:biosynthesis*; D006801:Humans; D008565:Membrane Proteins; D009131:Muscle, Smooth, Vascular / Q000187:drug effects* / Q000378:metabolism*; D009569:Nitric Oxide / Q000378:metabolism*; D019001:Nitric Oxide Synthase / Q000235:genetics / Q000378:metabolism; D052247:Nitric Oxide Synthase Type II; D011451:Prostaglandin-Endoperoxide Synthases / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats
chemical_list: D004731:Endotoxins; D008565:Membrane Proteins; D012333:RNA, Messenger; D009569:Nitric Oxide; D011464:Epoprostenol; C496319:NOS2 protein, human; D019001:Nitric Oxide Synthase; D052247:Nitric Oxide Synthase Type II; C496318:Nos2 protein, rat; D051546:Cyclooxygenase 2; C496540:PTGS2 protein, human; D011451:Prostaglandin-Endoperoxide Synthases