In vitro evaluation of the effect of dimethyl sulfoxide on equine articular cartilage matrix metabolism.
OBJECTIVE
To evaluate the effects of dimethyl sulfoxide (DMSO) on equine articular cartilage matrix metabolism.


METHODS
Using a cartilage explant culture system, proteoglycan (PG) synthesis, PG release, lactate metabolism, chondrocyte viability, and metabolism recovery were determined after cartilage exposure to DMSO.


METHODS
Cartilage harvested from metacarpophalangeal and metatarsophalangeal joints of 12 horses (age range, 1 to 10 years).


METHODS
Explants were exposed to concentrations of DMSO (1% to 20%) for variable times (3 to 72 hours). PG synthesis and release were determined by a radiolabel incorporation assay and dimethylmethylene blue (DMMB) dye assay, respectively. Lactate released into culture media was measured, and chondrocyte viability was assessed using the Formizan Conversion Assay and a paravital staining protocol. Metabolism recovery was assessed in explants that were allowed to recover in maintenance media after exposure to DMSO.


RESULTS
PG synthesis and lactate metabolism were inhibited in a dose- and time-dependent manner after exposure to DMSO concentrations > or = 5%; there was no significant alteration in PG release. No change in chondrocyte viability was detected after incubation with DMSO. PG synthesis and lactate metabolism returned to baseline rates when allowed a recovery period after exposure to DMSO.


CONCLUSIONS
DMSO concentrations > or = 5% suppress equine articular cartilage matrix metabolism. Suppression of PG synthesis and lactate metabolism is reversible and does not appear to be the result of chondrocyte death.


CONCLUSIONS
Equine clinicians adding DMSO to intraarticular lavage solutions should be aware that DMSO may have deleterious effects on equine articular cartilage matrix metabolism.
Veterinary Medical Teaching Hospital and the Department of Surgical and Radiological Sciences, School of Veterinary Medicine, University of California, Davis 95616, USA.
C L
CL
Smith
M H
MH
MacDonald
A M
AM
Tesch
N H
NH
Willits
D018712:Analgesics, Non-Narcotic / Q000494:pharmacology*; D000818:Animals; D002358:Cartilage, Articular / Q000187:drug effects* / Q000378:metabolism; D002470:Cell Survival / Q000187:drug effects; D019902:Chondrocytes / Q000166:cytology / Q000187:drug effects; D046508:Culture Techniques; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D006734:Horse Diseases / Q000628:therapy*; D006736:Horses / Q000378:metabolism*; D007592:Joint Diseases / Q000628:therapy / Q000662:veterinary*; D019344:Lactic Acid / Q000378:metabolism; D011509:Proteoglycans / Q000096:biosynthesis*; D007507:Therapeutic Irrigation / Q000662:veterinary
D018712:Analgesics, Non-Narcotic; D011509:Proteoglycans; D019344:Lactic Acid; D004121:Dimethyl Sulfoxide