title: Intra-articular hyaluronan (hyaluronic acid) and hylans for the treatment of osteoarthritis: mechanisms of action.
abstract: Although the predominant mechanism of intra-articular hyaluronan (hyaluronic acid) (HA) and hylans for the treatment of pain associated with knee osteoarthritis (OA) is unknown, in vivo, in vitro, and clinical studies demonstrate various physiological effects of exogenous HA. HA can reduce nerve impulses and nerve sensitivity associated with the pain of OA. In experimental OA, this glycosaminoglycan has protective effects on cartilage, which may be mediated by its molecular and cellular effects observed in vitro. Exogenous HA enhances chondrocyte HA and proteoglycan synthesis, reduces the production and activity of proinflammatory mediators and matrix metalloproteinases, and alters the behavior of immune cells. Many of the physiological effects of exogenous HA may be a function of its molecular weight. Several physiological effects probably contribute to the mechanisms by which HA and hylans exert their clinical effects in knee OA.
authors.affiliation: University of Alabama at Birmingham, Birmingham, AL, USA. Larry.Moreland@ccc.uab.edu
authors.forename: Larry W
authors.initials: LW
authors.lastname: Moreland
mesh_terms: D002356:Cartilage / Q000187:drug effects; D005109:Extracellular Matrix / Q000378:metabolism; D006801:Humans; D006820:Hyaluronic Acid / Q000008:administration & dosage / Q000031:analogs & derivatives / Q000502:physiology / Q000627:therapeutic use*; D007249:Inflammation / Q000188:drug therapy; D018836:Inflammation Mediators / Q000378:metabolism; D007270:Injections, Intra-Articular; D007962:Leukocytes / Q000187:drug effects / Q000276:immunology; D010003:Osteoarthritis / Q000188:drug therapy* / Q000209:etiology; D010146:Pain / Q000188:drug therapy; D013582:Synovial Fluid / Q000737:chemistry / Q000378:metabolism
chemical_list: D018836:Inflammation Mediators; C049816:hylan; D006820:Hyaluronic Acid