The effects of hyaluronic acid on fibronectin fragment mediated cartilage chondrolysis in skeletally mature rabbits.
OBJECTIVE
Intraarticular Na-Hyaluronate (HA) exerts a beneficial effect on adolescent rabbits after fibronectin fragment (Fn-f) mediated cartilage injury. We extended our studies to a population of rabbits which have reached full skeletal maturity.


METHODS
Adult male NZW rabbits received an injury with Fn-f and no further treatment; an injection of HA followed by Fn-f injury, or Fn-f injury followed by a single or weekly intraarticular injection of HA. All animals were sacrificed 38 days after receiving the Fn-f injury. After sacrifice, proteoglycan (PG) content was determined from articular cartilage from the medial femoral condyles and tibial plateaus. The patellae were processed for histology.


RESULTS
Cartilage PG contents were significantly reduced after Fn-f injection (P=0.0167) and were only slightly improved with HA pre-treatment. However, post-treatment with HA resulted in significant improvements in cartilage PG content when compared to Fn-f only (single HA, P=0.01; weekly HA,P =0.01). Loss of Safranin-O staining, cell loss, osteophyte formation and inflammation were present in the patellae following Fn-f injection. Pre-treatment with HA reduced these changes. More significant protection of cartilage and restoration of Fn-f injury were noted in animals receiving post-treatment with HA.


CONCLUSIONS
These results suggest that 38 days after Fn-f injury the lost PG content induced by Fn-f injection is substantially restored by weekly post-treatment with intraarticular HA in rabbits that have reached full skeletal maturity.
Williams
J M
JM
Department of Anatomy, Rush Medical College at Rush Presbyterian St Luke's Medical Center, 1653 West Congress Parkway, Chicago, IL 60612-3864, U.S.A. james_m_williams@rush.edu
Zhang
J
J
Kang
H
H
Ummadi
V
V
Homandberg
G A
GA
D000818:Animals; D002357:Cartilage Diseases / Q000188:drug therapy*; D002358:Cartilage, Articular / Q000187:drug effects* / Q000378:metabolism; D005353:Fibronectins / Q000008:administration & dosage; D006614:Hindlimb; D006820:Hyaluronic Acid / Q000494:pharmacology*; D010446:Peptide Fragments / Q000008:administration & dosage; D011509:Proteoglycans / Q000378:metabolism*; D011817:Rabbits
D005353:Fibronectins; D010446:Peptide Fragments; D011509:Proteoglycans; D006820:Hyaluronic Acid