title: Effects of methylprednisolone acetate and glucosamine on proteoglycan production by equine chondrocytes in vitro.
abstract: OBJECTIVE
  To evaluate the effects of methylprednisolone acetate (MPA) on proteoglycan production by equine chondrocytes and to investigate whether glucosamine hydrochloride modulates these effects at clinically relevant concentrations.
  
  
  METHODS
  Articular cartilage with normal gross appearance from metacarpophalangeal and metatarsophalangeal joints of 8 horses (1 to 10 years of age).
  
  
  METHODS
  In vitro chondrocyte pellets were pretreated with glucosamine (0, 1, 10, and 100 microg/mL) for 48 hours and exposed to MPA (0, 0.05, and 0.5 mg/mL) for 24 hours. Pellets and media were assayed for proteoglycan production (Alcian blue precipitation) and proteoglycan content (dimethylmethylene blue assay), and pellets were assayed for DNA content.
  
  
  RESULTS
  Methylprednisolone decreased production of proteoglycan by equine chondrocytes at both concentrations studied. Glucosamine protected proteoglycan production at all 3 concentrations studied.
  
  
  CONCLUSIONS
  Methylprednisolone, under noninflammatory conditions present in this study, decreased production of proteoglycan by equine chondrocytes. Glucosamine had a protective effect against inhibition of proteoglycan production at all 3 concentrations studied. This suggested that glucosamine may be useful as an adjunct treatment when an intra-articular injection of a corticosteroid is indicated and that it may be efficacious at concentrations relevant to clinical use.
authors.affiliation: Department of Veterinary Clinical Medicine, College of Veterinary Medicine, University of Illinois, Urbana-Champaign, IL 61801, USA.
authors.forename: Christopher R
authors.initials: CR
authors.lastname: Byron
authors.forename: Britany M
authors.initials: BM
authors.lastname: Benson
authors.forename: Allison A
authors.initials: AA
authors.lastname: Stewart
authors.forename: Holly C
authors.initials: HC
authors.lastname: Pondenis