Wang Wei-Ming, Jin Da-di, Lu Jian-Min, Wang Ben-Jie
Department of Orthopaedic, ZhongShan Hospital, Dalian University, Dalian 116001, China.
Zhonghua Yi Xue Za Zhi. 2007 Mar 6;87(9):622-6.
To develop a scientific and reproducible degenerative disc rat model for the study on the cervical disc and study the rule of migration associated with the chondrocytes in the nucleus pulposus.
The degenerative cervical disc animal model was developed in 40 infancy SD rats by means of forelimb amputation. Thirty-six normal rats in the same age served as the control. When the rats in the experimental group were 3, 6, 9 and 12 months (named E3, E6, E9 and E12 group respectively) and in the control group were 4, 8, 12 and 16 months (named C4, C8, C12 and C16 group respectively) postoperatively, the vertebral columns from C4-5 to C6-7 were removed and observed under radiographic and histological examination after the rats were sacrificed.
Light microscopy revealed that aging rat undergoes a chronological transition from a notochordal to a fibrocartilaginous NP. The chondrocytes found in mature nucleus pulposus originate and migrate from the cartilage endplate. The origin of chondrocytes proceeded in a centripetal direction from the periphery toward the center of the NP. In the periphery of NP, chondrocytes migrate along collagen fibers; in the center part of NP, chondrocytes migrate from endplate to NP in a parallel or vertical direction. Overload on the cervical spine elicited by this surgical intervention accelerated the process and resulted in cervical intervertebral disc degeneration thereafter.
The availability of this experimental model should be valuable for comprehensive understanding of the pathogenesis of cervical degeneration. The degeneration process of the bipedal rats'discs is in agreement with that of human beings. Chondrocytes in the rat NP originated and migrated from the cartilage endplate. There are different rules of the chondrocytes migrating from endplate associated with different period of degeneration and different region of nucleus pulposus.
建立一种科学且可重复的用于颈椎间盘研究的椎间盘退变大鼠模型，并研究髓核中软骨细胞的迁移规律。
通过前肢截肢在40只幼年SD大鼠中建立颈椎间盘退变动物模型。36只同龄正常大鼠作为对照。当实验组大鼠术后3、6、9和12个月（分别命名为E3、E6、E9和E12组），对照组大鼠术后4、8、12和16个月（分别命名为C4、C8、C12和C16组）时，处死大鼠后取出C4 - 5至C6 - 7节段的脊柱，进行影像学和组织学检查。
光学显微镜显示，衰老大鼠的髓核经历了从脊索样到纤维软骨样的时间性转变。成熟髓核中的软骨细胞起源于软骨终板并从其迁移而来。软骨细胞的起源从髓核周边向中心呈向心性进行。在髓核周边，软骨细胞沿胶原纤维迁移；在髓核中心部分，软骨细胞从终板以平行或垂直方向迁移至髓核。这种手术干预引起的颈椎过载加速了这一过程，随后导致颈椎间盘退变。
该实验模型的可用性对于全面理解颈椎退变的发病机制具有重要价值。双足大鼠椎间盘的退变过程与人类一致。大鼠髓核中的软骨细胞起源于软骨终板并从其迁移而来。在退变的不同时期和髓核的不同区域，软骨细胞从终板迁移存在不同规律。
