Plasma hyaluronan levels in rabbit immobilization osteoarthritis: effect of remobilization.
The right knee joint of 11 rabbits was immobilized in full extension with a splint for a period of three days. The effect of the immobilization and subsequent remobilization on plasma hyaluronan (HA) level was measured, using a sensitive radiometric HA binding protein (125I-HABP) assay. No significant effect of the immobilization on plasma HA level (54 +/- 4 micrograms/l) was noted, but shortly (45 minutes) after splint removal, plasma hyaluronate was at its highest (91 +/- 20 micrograms/l). One day after removal of the splint a return to baseline (53 +/- 6 micrograms/l) was observed. It is suggested that HA may accumulate in the joint during immobilization. Shortly after removing the splint, the level of HA shows a rise in many of the rabbits, even if this is not a consistent finding, probably due to variation in the extent and kinetics of the HA mobilization. Such an accumulation of HA could be deleterious for joint tissues, since HA is an-effective stimulator of interleukin-1 (also called catabolin) synthesis and secretion, and since immobilization osteoarthritis ensues in the splinted rabbit joints.
Konttinen
Y T
YT
Fourth Department of Medicine, Helsinki University Central Hospital, Finland.
Michelsson
J E
JE
Grönblad
M
M
Jaakkola
L
L
Honkanen
V
V
D000818:Animals; D006820:Hyaluronic Acid / Q000097:blood* / Q000502:physiology; D007103:Immobilization / Q000009:adverse effects* / Q000502:physiology; D007457:Iodine Radioisotopes; D009068:Movement / Q000502:physiology*; D010003:Osteoarthritis / Q000097:blood* / Q000209:etiology / Q000503:physiopathology; D011485:Protein Binding; D011817:Rabbits; D011874:Radiometry
D007457:Iodine Radioisotopes; D006820:Hyaluronic Acid