Delay. RhTGF-¦Â <sub> 1 </ Sub> And Practices On The Early Rabbit Cervical Disc Degeneration And Its Mechanism

The intervertebral discs(IVD) that were being made the model of degeneration were intervented by recombinant human transforming growth factor-β1(rhTGF-β1) and manipulation respectively. We studied that rhTGF-β1 and manipulation played the role in the course of the intervertebral disc degeneration (IVDD) respectively.The Japanese white rabbits were randomly divided into four groups named control group, TGF group, manipulation group and model group. The rabbits of the later three groups were made the model of IVDD. The model of stress type was used. That is to say, the rabbits were fixed in the special cases and kept their cervical spines into forty-five-degree flexion for five hours once a day. The IVDs of TGF group were infected directly rhTGF-β1(5ug/l) 20ul each IVD with mircoinjector in the narcosis state by telescreen before the first fixation. The rabbits were injected once two weeks, amounting to four times. According to this method, the IVDs of the other groups were injected PBS. The cervical spines of the manipulation group were manipulated once a day after fixation was over. Two months later, we observed the pictures of cervical spines taken with X-ray, the hisopathological changes under light microsopy and transmission electronic microscopy. The expression of Bcl-2 and Bax were determined by immunohistochemical analysis. The expression of collagen typeⅡmRNA of IVD (C5/6) was measured by the reverse transcription polymerize chain reaction (RT-PCR) and the bands was analyzed by bandware. We resolved proctologycan(PG) into glycosaminoglycan(GAG) with dilute alkali and protein, to distill GAG and calculate the weight of GAG a wet IVD.We found there was no difference in their X-ray pictures between four groups. The expression of Bcl-2, collagen typeⅡmRNA and the content of PG in the IVDs of the formal three groups were higher than those of the model group (P＜0.05), the expression of Bax in the IVDs of the formal three groups was lower than those of the model group (P＜0.05). There was no difference between the formal three groups (P＞0.05).We found that abmormal stress could decrease the expression of Bcl—2, collagen typeⅡmRNA and the content of PG and increase the expression of Bax in the IVDs. We thought that abmormal stress could induce the degeneration of IVD. Meanwhile, rhTGF-β1 or manipulation could increase the expression of Bcl-2, collagen typeⅡmRNA and the content of GAG and decrease the expression of Bax of IVDs in the abnormal stress state. Therefore, we inferred that rhTGF-β1 or manipulation could prevent and retard the degeneration of IVDs...