The Correlation Between Bone Density And Expression Of TGF-β1 And TNF-α MRNA In The Alveolar Bone With Experimental Diabetes

With the development of the society and the human aging the morbility of osteoporisis caused by diabetes is increasing. In recent years, dentists have paid more and more attention to it also. It has been suggested that diabetes may lead to osteoporosis of jaw bone and alveolar bone and make a great impact on incidence, severity and healing of periodontitis. But we do not clearly know the mechanism that diabetes worsens osteoporosis of alveolar bone, periodontitis and gingivitis. Accordingly, we established diabetic rat models, observed their bone density of alveolar bone, testified mRNA expression of transform growth factor -β1 and tumor necrosis factor -a in alveolar bone, investigate the effect of TNF-a and TGF-β1 on osteoporosis and discuss their relation between diabetes and periodontitis.Material and MethodsTwenty SD rats were randomly divided by following groups: normal rats (group N) and diabetic rats (group D). The diabetic rat models were established by injecting streptozotocin into their abdomen. After 8 weeks' duration of study, mRNA expression of TGF-β1 and TNF-a in the alveolar bone was measured by quantitativereverse transcription polymerase chain reaction (RT-PCR) respectively. In addition, bone density of the alveolar bone was measured by Dual Energy X-2 ray Bone Densitometer. And pathology made by papaffin embedding section and hematoxylin-eosin stain was analysedResultIn group D, the alveolar bone density showed a significant drop in contrast to group N determined by Dual Energy X-2 ray Bone Densitometer (p<0.01). Similarly, as showed by pathology, bone trabeculae of the alveolar bone in group D rats became tinier and thinner as compared to group N. Analyzed with statistics, mRNA expression of TGF-β1 and TNF-a in the alveolar bone of diabetic rats was increased obviously compared with normal rats (P<0.01).ConclusionIt is suggested that the alveolar bone in rats with diabetes mellitus have a tendency to develop osteoporosis. It may be related with increased expression of TGF-β1　 and TNF-a. The increased expression of TGF-β1 and TNF-a may be one of the mechanisms that Diabetes mellitus causes and promotes periodontitis.