| Objective: to determine the content changes of transforming growth factor-?(TGF-?)and insulin-like growth factor-1(IGF-1)in intervertebral disc tissue of diabetic rats caused by treatment of streptozotocin and normal rats in three different periods and discuss on the significance of differences between contents.Methods:1 Thirty male mature SD rats of three months old,randomly and equally divided into two groups,an experimental group and a control group.In the experimental group,SD rats were injected with streptozotocin solution,toxicity of streptozotocin to pancreatic islet ?-cells,leading to insulinproducing disorders that cause diabetes,establishment of diabetic rat model,and in the control group,no special treatment was conducted in SD rats,only intraperitoneal injection of sodium citrate buffer;2 Rats were sacrificed by intraperitoneal injection of 1% pentobarbital sodium,complete lumbar intervertebral discs of SD rats in each group were obtained in the 2nd,4th and 6th week respectively.Fixed with 4%paraformaldehyde,gradient ethanol dehydration,embedded into paraffin tissue block.Stained by hematoxylin and eosin(HE),after treated with xylene,the histopathological changes of the intervertebral disc were observed under microscope.Dewaxing by adding anti-secondary antibody,peroxidase labeled,DAB color.The levels of TGF-? and IGF-1 in intervertebral disc tissue were observed under microscope.Choose one of the most meaningful,positive expression of the strongest field of five to calculate.The cytoplasmic staining and positive cell rate were the criteria.Results:1 Compared with the normal group,the blood glucose concentration was significantly increased in the diabetic rats treated with streptozotocin injection,the difference was statistically significant(P<0.05),The blood glucose levels in the diabetic group were significantly different from those in the normal group at 2,4 and 6 weeks(P <0.05);2 In the three different periods,the rats in the experimental group showed varying degrees of degenerative changes.HE staining showed notochord cells reduction,proliferation of more collagen fibers,end plate showed varying degrees of calcification.The emergence of chondrocytes,fibrous rings were meandering arrangement,nucleus pulposus matrix disorder,decreased,showing varying degrees of shrinkage,nucleus pulposus and fibrous ring outward bulging.Part of the nucleus pulposus cells arranged in clusters,which is a sign of degeneration of the disc.While the control group of normal rats,intervertebral disc structure is normal.The endplate consists of a layer of transparent cartilage,the intervertebral disc is mainly fibroblasts.Nucleus pulposus and fiber ring boundaries clear,the cells in the matrix are enriched.3 According to immunohistochemical determination,The positive rate of TGF-? staining in the control group was no significant difference(P =0.368);The positive rate of IGF-1 staining in the control group was no significant difference(P = 0.368).There was no significant difference in the positive staining rate of TGF-? in the experimental group(P = 0.311).There was no significant difference in the positive staining rate of IGF-1 in the experimental group(P = 0.727),there were in three different periods,contents of both TGF-? and IGF-1 in intervertebral disc tissue of rats in the experimental group were significantly lower than those in the control group(P<0.05).Contents of TGF-? and IGF-1 detected in the two groups respectively were of no significant difference(P>0.05).Conclusion:The results of this study showed that the levels of TGF-?and IGF-1 in the intervertebral disc of STZ-induced diabetic rats in the experimental group were significantly lower than those in the control group.In the intervertebral disc HE staining can be observed,This reduction in TGF-?and IGF-I levels elicits the degradation of the intervertebral disc matrix,inhibition of cartilage matrix synthesis,so that the differentiation of undifferentiated mesenchymal cells decreased,accelerated intracranial collagen hydrolysis.Reduce the ability of chondrocyte phenotype in type II collagen and proteoglycan in intervertebral disc,and ultimately make the disc due to the lack of adequate matrix moisture and elastic decline,structural disorders,stability and metabolic physiological function changes,leading to disc degeneration,The results of this study demonstrate that diabetes can reduce the levels of TGF-? and IGF-1 in the intervertebral discs,which may be one of the causes of degeneration of discs in diabetic patients.This is the future of diabetic patients to prevent and treat degeneration of disc degeneration to provide a new treatment ideas. |
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