A Empirical Study Of Constructing Rabbit Model Of Lumbur Intervertebral Disc Degeneration

【Objective】To study the possibility of establishing a rabbit model of intervertebral disc degeneration induced by puncturing the anulus fibrosus with defined needle,and To develop a slowly progressive, reproducible rabbit model of lumbar intervertebral disc degeneration. It may be available for studying pathogenesis and pathophysiology of intervertebral disc degeneration and testing safe and effective therapy of intervertebral disc degeneration (e.g., growth factors therapy, gene therapy, cell therapy, and tissue engineering).【Method】A total of 24 male New Zealand white rabbits in ordinary grade(weighing approximately 3kg and one year old each)were studied, The operation was carried out in right retroperitoneal approach. The L2/3 intervetebral discs of 24 New Zealand white rabbits were stabbed by 16-gauge transfixion pin into a depth of 5mm in the right anterolateral annulus fibrosus(AF), Magnetic resonance imaging scans of the stabbed discs and intact L4/5 discs were perforned preoperatively and at 4,8,16 weeks respectively after surgery. The histologic and immunohistochemical analyses were perforned after the animals were killed and the materials were extracted.【Result】(1)In the magnetic resonance imaging, the stabbed discs exhibited a progressive decrease of signal intensity in T2-weighted images which start at preoperatively and last for 16 weeks after stabbing(P<0.01).(2)Histologic observation revealed progressive decrease of notochordal cells in nucleus pulposus(NP) which was increasingly occupied by disorganized, hypocellular fibrocartilaginous tissue,and there was general loss of definition between the NP and AF. (3) Immunohistochemical analyses revealed progressive decrease of type II collagen(P<0.01),while progressive increase of type I collagen in NP (P<0.01).【Conclusion】In This experiment the essential characteristic of rabbit model of intervertebral disc degeneration has been confirmed by the result of magnetic resonance imaging scans, histologic and immunohistochemical analyses. The stabbing approach result in a slowly progressive intervertebral disc degeneration in rabbit model. This model is available for progressively studying the intervertebral disc degeneration.