Apoptosis and nitric oxide in an experimental model of osteoarthritis in rabbit after hyaluronic acid treatment.
OBJECTIVE
this study determine the effect of hyaluronic acid on chondrocyte apoptosis, as well as variations in nitric oxide levels in an experimental model of osteoarthritis elicited anterior cruciate ligament section (ACL) in a rabbit model with two differentiated developmental periods.


METHODS
apoptosis and the quantification of nitric oxide (NO) were studied in two groups of 16 animals each. All animals had both knees operated, but only the right knees were treated with hyaluronic acid (HA). In the first group hyaluronic treatment was performed five weeks after osteoarthritis induction (short term group, ST) and in the second group, 10 weeks after induction (long term group, LT). The animals in both series were sacrificed two weeks after the last dose of HA. Flow cytometry by means of Annexin labelling and the TUNEL method were used for the study of apoptosis, NO levels were measured in cultured cartilage and in the supernatant of the enzymatic digestion of the cartilage.


RESULTS
regarding apoptosis measurement, a significant reduction in apoptosis levels was observed in both series as compared to untreated knees. NO production was lower in knees treated with HA, with significant differences after cartilage digestion.


CONCLUSIONS
The administration of HA has been effective ameliorating the damage associated with the process of osteoarthritis induced by experimental surgery as evidenced by decreased apoptosis (TUNEL method), the results more promising in the earlier phases of the disease.
Díaz-Gallego
Luis
L
Department of Orthopedic Surgery, Hospital of León, Spain.
Prieto
Julio G
JG
Coronel
Pilar
P
Gamazo
Luis E
LE
Gimeno
Mercedes
M
Alvarez
Ana I
AI
D000818:Animals; D000070598:Anterior Cruciate Ligament Injuries; D017209:Apoptosis / Q000187:drug effects*; D002356:Cartilage / Q000378:metabolism / Q000473:pathology; D004195:Disease Models, Animal; D006820:Hyaluronic Acid / Q000494:pharmacology*; D020287:In Situ Nick-End Labeling; D009569:Nitric Oxide / Q000096:biosynthesis*; D010003:Osteoarthritis / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D011817:Rabbits
D009569:Nitric Oxide; D006820:Hyaluronic Acid