| 1. The influence of central nervous system injury to rats femoralfracture healingObjective: To study the effect of healing of femoral fractures in rats afterbrain and spinal cord injuries. Methods: 54 Male Wistar rats were randomly divided into 3 groups: The group of only fractures composed of 18 rats, the brain injuries+femoral fracture 18 rats,spinal cord injuries+femoral fracture 18 rats.The animals were sacrificed?, 14,and 28 day after surgery.observed gross sample, measured callus volume .studied the callus in the X-RAY films. The callus of were stained by HE. Results: In the group of central nervous injuries,bone callus were bigger and faste formed than those in the groups of only fracture. Conclusion: The fracture healing rate in the central nervous injuries is faster than the group only femoral fracture.2. The expression of neuropeptides and NGF in rats callus following central nervous system injuryObjective: To investigate the expression of neuropeptides and NGF incallus tissue of femoral fractures after brain spinal cord injuries. Methods: 90 Male Wistar rats were randomly divided into 3 groups: The group of only and femoral fractures composed of 30 rats ,the brain injuries+femoral fracture 30 rats,spinal cord injuries+femoral fracture 30rats.The animals were sacrificed in day 4,7,14,2land 28 day after surgery. The callus were stained by immunohistochemistry of CGRP, SP, NGF. The positive cells wereanalyzed by a computer image system. Results: In the group of central nervous injuries .positive CGRP, SP, NGF increased rapidly after operation at 1 week, reached peaking at 2 week, Neuropeptides and NGF were strongly expressed in osteoblasts and chondrocytes and fibroblast. the central nervous system injury group had a significant higher than only fracture group. In addition ,the brian group induced a more significant increase in CGRP than did spinal cord injuries.the differences were obvious comparing with only bone fracture group. Conclusion: Neuropeptides and NGF have significant effect on bone fracture healing, the expression of Neuropeptides and NGF showed different expression in different period of fracture healing, Neuropeptides and NGF increase in callous with central nerve centre injuris rats, this fact indicated that NP and NGF were involved in fracture healing.3. The expression of neuroPeptides receptor and the effects on the Expression of IGF-I and IGF-IR mRNA in Rat OsteoblastsObjective: To investigate the expression of neuropeptides receptors of CGRP, SP in rat osteoblast and the effects of neuropeptides calciteonin gene-related peptide(CGRP), SP on the gene expression of insulin-like growth factor I (IGF-I) and insulin-like growth factor type I receptor (IGF-IR) in cultured rat osteoblasts in vitro? Method: The secondary cultured osteoblasts were culured in media containing 10"u~107M CGRP, SP, After 6hours ,12hours and 24 hours of incubation, the presence of CGRP or SPreceptors in rat osteoblast were detected by immunohistochemistry. in situ hybridization was performed to observe the time and dose-efficiency relations of IGF-I and IGF-I mRNA expression with control groups . Results: There were CGRP receptor and SP receptor expression on the cultured rat osteoblasts .. there was a significant effect of neuropeptides on rate of growth of the cultured rat osteoblasts in vitro,CGRP uprugulated the mRNA expression of IGF-I, with the maximal effect at the concentration of 10"8 M for 12 hours. CGRP also upregulated the mRNA expression of IGF-IR depending on the time and dose-efficiency . the study found SP also can incressed the mRNA expression of IGF-1,but the expression peaking was 10~6 M for 12 hours. Conclusion: Neuropeptides may promote the autocrine IGF-Iof osteoblastes and to regulate the activities of osteoblastes, So it may play an important role in bone remolding . |
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