title: Edema in oral mucosa after LPS or cytokine exposure.
abstract: Lowering of interstitial fluid pressure (P(if)) is an important factor that explains the rapid edema formation in acute inflammation in loose connective tissues. Lipopolysaccharide (LPS) and the pro-inflammatory cytokines interleukin-1beta (IL-1beta) and tumor necrosis factor-alpha (TNF-alpha) are pathogenetic in gingivitis. To test if these substances induce lowering of P(if) in rat oral mucosa, we measured P(if) with a micropuncture technique. IL-1beta and TNF-alpha caused lowering of P(if), whereas LPS induced an immediate increase in P(if), followed by lowering after 40 min. Measurements of fluid volume distribution showed a significant change in interstitial fluid volume (V(i)) 1.5 hr after LPS exposure as V(i) changed from 0.41 +/- 0.02 to 0.51 +/- 0.03 mL/g wet weight (p < 0.05), confirming edema. These findings show that LPS, IL-1beta, and TNF-alpha induce lowering of P(if) in the rat oral mucosa and contribute to edema formation in LPS-induced gingivitis.
authors.affiliation: Institute of Biomedicine, Section for Physiology, Faculty of Medicine, University of Bergen, Norway. Nancy.Bletsa@biomed.uib.no
authors.forename: A
authors.initials: A
authors.lastname: Bletsa
authors.forename: T
authors.initials: T
authors.lastname: Nedrebø
authors.forename: K J
authors.initials: KJ
authors.lastname: Heyeraas
authors.forename: E
authors.initials: E
authors.lastname: Berggreen
mesh_terms: D000818:Animals; D003238:Connective Tissue / Q000187:drug effects; D004487:Edema / Q000139:chemically induced*; D045604:Extracellular Fluid / Q000187:drug effects*; D005891:Gingivitis / Q000503:physiopathology*; D006874:Hydrostatic Pressure; D007375:Interleukin-1 / Q000494:pharmacology*; D008070:Lipopolysaccharides / Q000494:pharmacology*; D009061:Mouth Mucosa / Q000187:drug effects*; D051381:Rats; D014409:Tumor Necrosis Factor-alpha / Q000494:pharmacology*
chemical_list: D007375:Interleukin-1; D008070:Lipopolysaccharides; D014409:Tumor Necrosis Factor-alpha