Effect of intramuscularly administered polysulfated glycosaminoglycan on articular cartilage from equine joints injected with methylprednisolone acetate.
Intra-articularly administered, long-acting corticosteroids are a beneficial treatment for many equine joint disorders because they alleviate inflammation and signs of pain, but they also exert detrimental effects on the biochemical composition and morphologic features of articular cartilage. Chondroprotective drugs have been shown to mitigate some of the deleterious effects of intra-articularly administered corticosteroids on articular cartilage of laboratory animals. Twenty-one ponies were assigned at random to receive 1 of 3 treatments in the right middle carpal joint. Group-1 ponies (n = 8) had methylprednisolone acetate (MPA; 0.2 mg/kg of body weight) and saline solution administered intra-articularly and IM, respectively. Group-2 ponies (n = 9) received MPA (0.2 mg/kg) and polysulfated glycosaminoglycan (GAG; 2 mg/kg). Group-3 ponies (control; n = 4) had saline solution administered intra-articularly and IM. The corticosteroid or saline solution was injected into the right middle carpal joint on day 1. The IM administered polysulfated GAG or saline solution was administered at the same time, then was repeated every 3 days for 20 days. Ponies were euthanatized 21 days after initial injection by overdose of pentobarbital sodium. The cartilage of younger ponies was significantly (P < 0.05) more responsive to the proteoglycan-depleting effects of MPA. Ponies < 10 years old of groups 1 and 2 had significantly (P < 0.05) lower GAG content in the articular cartilage than did control ponies. Systemic treatment with polysulfated GAG did not result in a protective effect against proteoglycan loss from the articular cartilage.(ABSTRACT TRUNCATED AT 250 WORDS)
Fubini
S L
SL
Department of Clinical Sciences, College of Veterinary Medicine, Cornell University, Ithaca, NY 14853.
Boatwright
C E
CE
Todhunter
R J
RJ
Lust
G
G
D000818:Animals; D000893:Anti-Inflammatory Agents / Q000037:antagonists & inhibitors* / Q000378:metabolism; D002358:Cartilage, Articular / Q000187:drug effects* / Q000378:metabolism; D005353:Fibronectins / Q000378:metabolism; D006025:Glycosaminoglycans / Q000378:metabolism / Q000494:pharmacology*; D006736:Horses / Q000378:metabolism*; D007273:Injections, Intramuscular / Q000662:veterinary; D007632:Keratan Sulfate / Q000378:metabolism; D008775:Methylprednisolone / Q000031:analogs & derivatives* / Q000037:antagonists & inhibitors / Q000494:pharmacology; D000077555:Methylprednisolone Acetate; D010314:Partial Thromboplastin Time / Q000662:veterinary; D013582:Synovial Fluid / Q000378:metabolism
D000893:Anti-Inflammatory Agents; D005353:Fibronectins; D006025:Glycosaminoglycans; C013786:A73025; D000077555:Methylprednisolone Acetate; D007632:Keratan Sulfate; D008775:Methylprednisolone