Effect Of Calcitonin In The Intervertebral Disc Degeneration

Objective:To observe the role of calcitonin in the process of disc degeneration, and explore themechanism of action of calcitonin, and provide a theoretical basis for the conservativetreatment of disc degeneration.Methods:1. Experiment Procedure60Newland rabbits were prepared operation model, and10rabbits were randomlyselected into operation model. Two weeks and Four weeks after operation all the rats werekilled. the level of intervertebral disk were determinated in pre-operative and postoperative with underwent MRI.The specimens was fixed in10%formalin for24hour andembedded in paraffin, and5mm sections from the paraffin blocks were stained withhematoxylin and eosin. Histological analysis of the nucleus pulposus was performed by asurgical pathologist. The rest of50rabbits were randomly divided10group(B1C1D1E1F1,B2C2D2E2F2).Histological analysis was performed.The rabbits in the control group were injected with the saline and killed at2,4monthspostoperatively, Respectively.CT at concentration of1，2,4，8IU/Kg was injected in theC1D1E1F1group, The rabbits in the C2D2E2F2group were killed on month2postoperatively.2. Outcome measures2.1All rabbits were killed at designated time and underwented MR imaging toexamine Disc height.2.2The specimens was fixed in10%formalin for24hour and embedded in paraffin,and5mm sections from the paraffin blocks were stained with hematoxylin and eosin. Allnucleus pulposus were evaluated histologically.The amount of the proteoglycan in nucleuspulposus were counted by the Safranine staining slice. The expression of PCNA in intervertebral disk were assessed by the immunohistochemical slice and expressed as thepercentage of positive cells counted in the selected fields.3. Statistical analysisThe statistical analysis was performed using SPSS software (version16.0, SPSS, Inc.).Data are expressed as the mean±standard deviation for the number of experimentsindicated, and a paired t-test was used for the determination of statistical significancebetween the groups.A probability level less than0.05was considered statisticallysignificant.Results:1. An intervertebral disc degeneration was significantly less in the CT-treated groupscompared with the control groups(P<0.05).2. Compared to month2after CT-treated,there was an overall significant difference atmonth1after CT-treated (P <0.05),3. No significant differences were found between the8IU/Kg CT at1monthpostoperatively and the4IU/Kg CT groups at2month postoperatively (P>0.05)4. The difference between4IU/Kg CT group and8IU/Kg CT on month2post-operatively group was not significant (P>0.05).Conclusion:1. The intervertebral space and the height of disc are decreasing in the interverbraldisc degeneration process,the nucleus pulposus nucleus proteoglycan is lost,the nucleuspulposus nucleus proteoglycan is lost, the annulus fibrosus collagen is thinning andinterrupting the expression of the type II collagen in the cartilage cell is decreasing andLoose.2. CT can low the intervertebral disc degeneration, increasing the height of the disc,reducing the loss of the easygoing cell proteoglycans and making fibrous ring of cartilagethickening,increasing the expression of type II collagen.3. Application of calcitonin threshold peak, plateau time, and reach the half-life, Theefficacy was consistency without changing following doses and application intervals.