Effects of sodium hyaluronate and methylprednisolone acetate on proteoglycan synthesis in equine articular cartilage explants

Aimie J. Doyle College of Veterinary Medicine, University of Illinois, 1008 W Hazelwood Dr, Urbana, IL 61802.
Present address is West Wind Veterinary Hospital, 51136 Range Rd 212, Sherwood Park, AB, Canada T6K 1E7.

Search for other papers by Aimie J. Doyle in
Current site
Google Scholar
PubMed
Close
 DVM
,
Allison A. Stewart College of Veterinary Medicine, University of Illinois, 1008 W Hazelwood Dr, Urbana, IL 61802.

Search for other papers by Allison A. Stewart in
Current site
Google Scholar
PubMed
Close
 DVM, MS
,
Peter D. Constable College of Veterinary Medicine, University of Illinois, 1008 W Hazelwood Dr, Urbana, IL 61802.

Search for other papers by Peter D. Constable in
Current site
Google Scholar
PubMed
Close
 BVSc, PhD
,
Jo Ann C. Eurell College of Veterinary Medicine, University of Illinois, 1008 W Hazelwood Dr, Urbana, IL 61802.

Search for other papers by Jo Ann C. Eurell in
Current site
Google Scholar
PubMed
Close
 DVM, PhD
,
David E. Freeman College of Veterinary Medicine, University of Illinois, 1008 W Hazelwood Dr, Urbana, IL 61802.

Search for other papers by David E. Freeman in
Current site
Google Scholar
PubMed
Close
 MVB, PhD
, and
Dominique J. Griffon College of Veterinary Medicine, University of Illinois, 1008 W Hazelwood Dr, Urbana, IL 61802.

Search for other papers by Dominique J. Griffon in
Current site
Google Scholar
PubMed
Close
 DVM, PhD

Abstract

Objective—To determine effects of sodium hyaluronate (HA) on corticosteroid-induced cartilage matrix catabolism in equine articular cartilage explants.

Sample Population—30 articular cartilage explants from fetlock joints of 5 adult horses without joint disease.

Procedure—Articular cartilage explants were treated with control medium or medium containing methylprednisolone acetate (MPA; 0.05, 0.5, or 5.0 mg/mL), HA (0.1, 1.0, or 1.5 mg/mL), or both. Proteoglycan (PG) synthesis was measured by incorporation of sulfur 35-labeled sodium sulphate into PGs, and PG degradation was measured by release of radiolabeled PGs into the medium. Total glycosaminoglycan (GAG) content in media and explants and total explant DNA were determined.

Results—Methylprednisolone acetate caused a decrease in PG synthesis, whereas HA had no effect. Only the combination of MPA at a concentration of 0.05 mg/mL and HA at a concentration of 1.0 mg/mL increased PG synthesis, compared with control explants. Methylprednisolone acetate increased degradation of newly synthesized PGs into the medium, compared with control explants, and HA alone had no effect. Hyaluronate had no effect on MPAinduced PG degradation and release into media. Neither MPA alone nor HA alone had an effect on total cartilage GAG content. Methylprednisolone acetate caused an increase in release of GAG into the medium at 48 and 72 hours after treatment. In combination, HA had no protective effect on MPA-induced GAG release into the medium. Total cartilage DNA content was not affected by treatments.

Conclusions and Clinical Relevance—Our results indicate that HA addition has little effect on corticosteroid- induced cartilage matrix PG catabolism in articular cartilage explants. (Am J Vet Res 2005;66:48–53)

Abstract

Objective—To determine effects of sodium hyaluronate (HA) on corticosteroid-induced cartilage matrix catabolism in equine articular cartilage explants.

Sample Population—30 articular cartilage explants from fetlock joints of 5 adult horses without joint disease.

Procedure—Articular cartilage explants were treated with control medium or medium containing methylprednisolone acetate (MPA; 0.05, 0.5, or 5.0 mg/mL), HA (0.1, 1.0, or 1.5 mg/mL), or both. Proteoglycan (PG) synthesis was measured by incorporation of sulfur 35-labeled sodium sulphate into PGs, and PG degradation was measured by release of radiolabeled PGs into the medium. Total glycosaminoglycan (GAG) content in media and explants and total explant DNA were determined.

Results—Methylprednisolone acetate caused a decrease in PG synthesis, whereas HA had no effect. Only the combination of MPA at a concentration of 0.05 mg/mL and HA at a concentration of 1.0 mg/mL increased PG synthesis, compared with control explants. Methylprednisolone acetate increased degradation of newly synthesized PGs into the medium, compared with control explants, and HA alone had no effect. Hyaluronate had no effect on MPAinduced PG degradation and release into media. Neither MPA alone nor HA alone had an effect on total cartilage GAG content. Methylprednisolone acetate caused an increase in release of GAG into the medium at 48 and 72 hours after treatment. In combination, HA had no protective effect on MPA-induced GAG release into the medium. Total cartilage DNA content was not affected by treatments.

Conclusions and Clinical Relevance—Our results indicate that HA addition has little effect on corticosteroid- induced cartilage matrix PG catabolism in articular cartilage explants. (Am J Vet Res 2005;66:48–53)

Advertisement