Empirical Study Of The Effect Of Estrogen On Expression Of IL-20 And MMP-3 In Nucleus Pulposus Of Lumbar Intervertebral Disc Of Rabbit Performed By Ovariectomy

Objective: basing establishing the model of intervertebral discs degeneration due to the lack of estrogen,using estrogen replacement therapy(ERT), the method of immunohistochemistry and western-blot to examine the effects of estrogen on Expression of IL-20 and MMP-3 in the nucleus pulposus of Lumbar Intervertebral Disc.Use the process of Pathology,MRI and electron microscope to observe intervertebral discs tissue and the change of ultrastructure.This study investigate the contribution to the expression of MMP-3 and IL-20 in the nucleus pulposus of Lumbar Intervertebral Disc degeneration by estrogen and mechanism of actionMethods:The animal model was established with female Newzeland rabbits.The 32 New-Zealand rabbits were randomly divided into the negative control group(no treatment,A group),experimental blank control group(by ovariectomy only,B group),low dose ERT after ovariectomy group(C gpoup) and large dose ERT after ovariectomy group(D gpoup) with 8 animals in each group.From the one week after operation,A group and B group was performed intramuscular with Sodium Chloride 2ml,C group was performed intramuscular with Estradiol Benzoate(E2) 0.2mg every other day (EOD).D group was performed intramuscular with Estradiol Benzoate(E2)1mg EOD. last three months, then all the animals wae checked by MRI,after that,the tissue of lumbar nucleus gelatinosus was taken to observe by electron microscope and Pathology ,and the expression of IL-20 and MMP-3 was tested by immunohistochemistry and western-blot.Results: Establish animal model of intervertebral discs degeneration imitating post-menopause wemen succesfully by ovariectomy. pathology display that nucleus pulposus cells reduce and degenerat on different levels in the nucleus pulposus of intervertebral discs degeneration。Nucleus pulposus cells decreasing,many necrosis remnant, cell ecptoma reducing or vanishing, organelle and glycogenosome reducing obviously were discovered by electron microscope。MRI display that T2 signal of B group depress.A,C and D groups chanange disapparentely(P<0.05). immunohistochemistry and western-blot indicate that Expression of IL-20 and MMP-3 in A,C and D group are weakly positive.IN B group are hadropositive(P<0.05).conclusion:MMP-3 and IL-20 have a close relation with intervertebral discs degeneration,and have the dependablity with the degree of degeneration. Estrogen can make the expression of IL-20 and MMP-3 to reduce,thereby degradation of intervertebral discs ECM to ease. Then to restrain and defer the formation and development of intervertebral discs degeneration.