The Effects Of The IL-1Ra On The Metabolism Of PGE₂, PGF_1α And 5-HT In The Rabbit Nucleus Pulposus

Objective: To evaluate the effects of the interleukin-1 receptor antagonist protein on the metabolism of the prostaglandinE₂ (PGE₂), 6-keto- prostaglandinF₁α (PGF₁α) and 5-OH-tryptamine (5-HT) in the nucleus pulposus of lumbar intervertebral disc.Methods: Japanese white rabbits were used. The lumbar nucleus pulposus were separated and cultured in DMEM medium in vitro. After30 hours of culture with or without human recombinant interleukin-1( (rhIL-1() and interleukin-1 receptor antagonist (rhIL-1Ra) protein, the content of the PGE₂, PGF₁α and 5-HT in culture medium were measured, respectively. And after the addition of rhIL-1( and rhIL-1Ra protein to the tissue culture medium of the nucleus pulposus, PGE₂, PGF₁α and 5-HT of the culture medium were assayed in 12, 24, 72 hours, respectively.Results: The concentrations of PGE₂, PGF₁α and 5-HT in culture medium with the additional rhIL-1( increased more significantly than these in the control groups. The concentrations of PGE₂, PGF₁α and 5-HT increased markedly with the time of culture. The concentrations of PGE₂, PGF₁α and 5-HT in culture medium decreased progressively along with the concentrations of the rhIL-1Ra protein, the concentrations of the culture medium increased with the time of culture. But the concentrations decreased quite obviously in the groups of rhIL-1( and rhIL-1Ra protein, compared with the rhIL-1( ones.Conclusion: IL-1( can stimulate synthesis of PGE₂, PGF₁α and 5-HT of the nucleus pulposus of lumbar intervertebral disc, The effect shows a time dependency. rhIL-1Ra protein suppresses the stimulation of PGE₂,PGF₁α and 5-HT synthesis by IL-1(. The effect shows a concentration dependency.