Objective To investigate the effect of oral administration of arginine on linear growth of long bones in male pubertal rats and the underlying mechanisms, focusing on expression of genes related to the hypothalamus-pi...Objective To investigate the effect of oral administration of arginine on linear growth of long bones in male pubertal rats and the underlying mechanisms, focusing on expression of genes related to the hypothalamus-pituitary growth axis and the nitric oxide （NO）-cyclic guanosine monophosphate （cGMP） pathway. Methods Rats were randomly divided into control and intervention groups. In the intervention group, arginine was solved in water （0.045 g L-arginine was mixed with 1 mL water） and administered in rats （10 mL/kg） through gastric perfusion once per day, for totally 28 d. Rats in the control group received normal saline treatment. Bone histomorphometry analysis was used to measure growth plate width and mineral apposition rate of the tibia, as well as trabecular bone volume fraction, osteoblast surface and osteo- clast surface of the femur. Serum growth hormone （GH） concentration was determined by radioimmunoassay. Real-time PCR was used to measure the expression of neuronal nitric oxide synthase （nNOS）, soluble guanylyl cyclases （sGCal and sGCfll）, growth hormone-releasing hormone （Ghrh） and somatostatin （SS） in hypothalamus, as well as Gh in pituitary. Western blot was used to detect the protein levels ofnNOS, sGCα1 and sGCβ1 in hypothalamus. Results After treat- ment with arginine, the growth plate width of tibia and osteoblast surface of femur were increased （P 〈 0.05）, and serum GH concentration was elevated （P 〈 0.05）. Besides, mRNA and protein levels ofnNOS and sGCα1 （P 〈 0.05）, as well as the expression of Gh mRNA （P 〈 0.01）, were significantly up-regulated, while the expression of SS mRNA was down- regulated （P 〈 0.05）. Conclusion Oral administration ofarginine could improve linear growth of long bones by regulating mRNA expression of SS and Gh and inducing GH secretion, possibly via nNOS-NO-sGC-cGMP signal transduction pathway.展开更多
There is plenty of literature on masticatory function and its impact on maxillofacial development. However, the influence of masticatory hypofunction on bone turnover in the alveolar bone has hardly been studied. This...There is plenty of literature on masticatory function and its impact on maxillofacial development. However, the influence of masticatory hypofunction on bone turnover in the alveolar bone has hardly been studied. This study aimed to clarify the influence of tooth loss and soft diet on the alveolar bone turnover during the growth period. Three-week-old Wistar rats were randomly divided into the following three groups: Hard diet group (rats raised on solid standard diet), Powder diet group (rats raised on powdered standard feed diet), and Extraction group (rats raised on powdered standard diet with maxillary molars extraction). BV, BMC, and BMD in the cancellous bone of M1 were measured using micro-CT analysis. To analyze the histological bone turnover, we prepared non-decalcified thin sections of alveolar cancellous bone when rats were 20 weeks old. On three-dimensional constructed images, the experimental groups (the Powder diet and Extraction groups) showed expansion of the medullary cavity of the interradicular septum of the first molar compared to controls (the Hard diet group). BV, BMC, and BMD were significantly lower in the experimental groups, with the difference from controls being greater in the Extraction group. On histomorphometric analysis, the bone mass parameters, bone formation parameters, and bone mineralization parameters were significantly lower in the experimental groups compared to controls. The bone resorption parameters were significantly higher in the experimental groups. From this study, we found that soft diet and tooth loss might worsen the bone microstructure, reduce osteogenesis, and promote bone resorption in alveolar bone.展开更多
Objective:To investigate the effects of chronic sleep deprivation(CSD)on bone microstructure and peak bone mass(PBM)in SD rats.Methods:Twenty-four SD rats were randomly divided into CSD group and control group.In the ...Objective:To investigate the effects of chronic sleep deprivation(CSD)on bone microstructure and peak bone mass(PBM)in SD rats.Methods:Twenty-four SD rats were randomly divided into CSD group and control group.In the CSD group,a CSD model was established using a new sleep deprivation instrument for rats and mice,and intervened for 5 weeks.Bone turnover markers including P1NP and CTX-1 before and after the experiment were observed.After the experiment,the left femur were scanned by Micro-CT,and the cortical bone and bone trabecula were three-dimensionally reconstructed,respectively.The bone mineral density(BMD)and relevant parameters were detected.Results:CT images of the femur(proximal ends)showed significant trabecular loss in CSD rats.Trabecular parameters including bone volume fraction(BV/TV),trabecular number(Tb.N)and trabecular separation(Tb.Sp)in the CSD group were all lower than those in the control group.The bone cortex of the middle segment of the femur and tibia in CSD rats was also lower than that in the control group.The parameters of bone cortex including total tissue area(Tt.Ar),cortical bone area(Ct.Ar)and cortical bone thickness(Ct.Th)in the CSD group were significantly lower than those in the control group(P<0.01).After chronic CSD,BMD of both bone trabecula and bone cortex of the femur was lower,while the corresponding P1NP and CTX-1 were significantly higher than those in the control group.Conclusion:Sleep plays an important role in PBM formation.CSD accelerates bone turnover and thus significantly reducing PBM in SD rats.展开更多
Objective： To observe the effects of Bushen Zhuanggu Formul on intedeukin 6 （IL-6） level and bone metabolism of the ovariectomized rats, and to explore the possible mechanism of preventing and treating postmenopaus...Objective： To observe the effects of Bushen Zhuanggu Formul on intedeukin 6 （IL-6） level and bone metabolism of the ovariectomized rats, and to explore the possible mechanism of preventing and treating postmenopausal osteo porosis by traditional Chinese Formul. Methods： SD rats were randomly divided into 4 groups： normal control group （N）, ovariectomized control group （OVX）, estrogen-treated group （OVX＋E） traditional and Chinese medicine-treated group （OVX＋ CM）. After treaanent, IL-6 levels in rat bone tissue media and serum were examined by ELISA. The proximal tibias（PTM） of rats were undecalcified for quantitative bone histomorphometry. Results： Compared with OVX group, both Bushen Zhuanggu medicine and estrogen decreased IL-6 level in rat bone tissue media. However, the effects of Bushen Zhuanggu Formul were weaker than those of estrogen. Furthermore, Bushen Zhuanggu Formul and estrogen produced a reduction in bone turnover by inhibiting bone formation and bone resorption at the same time. Conclusion： Bushen Zhuanggu Formul prevents ovariectomic bone loss by inhibiting IL-6 production in rat bone tissues.展开更多
The effects of childhood masticatory function loss and soft foods on the mandibular condyle have been the subject of much research. However, the corresponding bone turnover is not fully understood. The purpose of the ...The effects of childhood masticatory function loss and soft foods on the mandibular condyle have been the subject of much research. However, the corresponding bone turnover is not fully understood. The purpose of the present study was to clarify the effects of a lack of teeth and a soft food diet during the growth period on bone turnover in the mandibular condyle. We divided 3-week-old Wistar rats into the following three groups: 1) Extraction group: The maxillary molars were extracted at the age of 4 weeks, and animals were fed powdered standard feed. 2) Powder group: Animals were fed powdered standard feed without tooth extraction. 3) Control group: Animals were fed solid standard feed without tooth extraction. Non-decalcified thin-slice specimens of sagittal sections of the mandibular condyle were obtained at the age of 20 weeks for histological analysis. We used micro-CT analysis and bone histomorphometry to measure bone volume (BV), bone mineral content (BMC), bone mineral density (BMD), bone microstructure, bone resorption, and osteogenesis in the mandibular condyle, and we compared the results among groups. In the extraction and the powder groups, we found deformation and disruption of the arrangement of chondrocytes, coagulation of chondrocytes, and duplication of the tidemark in the cartilage. We also found an increase in multinuclear osteoclasts in the cancellous bone. We found a reduction in BV, BMC, and BMD in the extraction and powder groups compared to the control group, as well as a reduction of bone volume, a lowering of osteogenesis parameters, and an increase in bone resorption parameters in the secondary cancellous bone. These results suggest that a lack of teeth and a soft food diet during the growth period cause a decline in bone microstructure, a decrease in osteogenesis, and an increase in bone resorption.展开更多
Objective To Investigate stress adaptability of freeze-dried bone allograft.Methods Cortical and cancellous allograft were transplanted to each side of the midshaft diaphyseal ulna in two groups of 28 animals.The left...Objective To Investigate stress adaptability of freeze-dried bone allograft.Methods Cortical and cancellous allograft were transplanted to each side of the midshaft diaphyseal ulna in two groups of 28 animals.The left transplanted allograft was free from fixation and bore a normal physiological lcad,while the right transplanted allograft was protected from loading by a simple external fixator and bore less load.Animals were sacrificed at the 2nd,4th,8th,16th week after transplantation and specimens were taken out for bone histomorphometry studies and analysis of collagen gene expression by in situ Cdna-Mrna hybridization.Results Labeled surface(LS)and bone mineral apposition rate(MAR)of the normally loaded graft-host bone interface were significantly higher than that of the less loaded side at the 4th,8th,16th week after transplantation.Parameters reflecting the internal repair process of the allograft,such as LS in cortical and cancellous bone or MAR in cortical bone of the normally loaded side were significantly higher than those of the less loaded side at the 16th week after transplantation.The result of in situ hybridization indicated that more osteoblast-like cells expressing the type Ⅰ collagen gene were found in the interface or interior of normally loaded grafts.Conclusion The stimulus of physiologic load can accelerate the early union of allograft-host bone interface and later new bone creep substitution to the necrotic allograft.展开更多
文摘Objective To investigate the effect of oral administration of arginine on linear growth of long bones in male pubertal rats and the underlying mechanisms, focusing on expression of genes related to the hypothalamus-pituitary growth axis and the nitric oxide （NO）-cyclic guanosine monophosphate （cGMP） pathway. Methods Rats were randomly divided into control and intervention groups. In the intervention group, arginine was solved in water （0.045 g L-arginine was mixed with 1 mL water） and administered in rats （10 mL/kg） through gastric perfusion once per day, for totally 28 d. Rats in the control group received normal saline treatment. Bone histomorphometry analysis was used to measure growth plate width and mineral apposition rate of the tibia, as well as trabecular bone volume fraction, osteoblast surface and osteo- clast surface of the femur. Serum growth hormone （GH） concentration was determined by radioimmunoassay. Real-time PCR was used to measure the expression of neuronal nitric oxide synthase （nNOS）, soluble guanylyl cyclases （sGCal and sGCfll）, growth hormone-releasing hormone （Ghrh） and somatostatin （SS） in hypothalamus, as well as Gh in pituitary. Western blot was used to detect the protein levels ofnNOS, sGCα1 and sGCβ1 in hypothalamus. Results After treat- ment with arginine, the growth plate width of tibia and osteoblast surface of femur were increased （P 〈 0.05）, and serum GH concentration was elevated （P 〈 0.05）. Besides, mRNA and protein levels ofnNOS and sGCα1 （P 〈 0.05）, as well as the expression of Gh mRNA （P 〈 0.01）, were significantly up-regulated, while the expression of SS mRNA was down- regulated （P 〈 0.05）. Conclusion Oral administration ofarginine could improve linear growth of long bones by regulating mRNA expression of SS and Gh and inducing GH secretion, possibly via nNOS-NO-sGC-cGMP signal transduction pathway.
文摘There is plenty of literature on masticatory function and its impact on maxillofacial development. However, the influence of masticatory hypofunction on bone turnover in the alveolar bone has hardly been studied. This study aimed to clarify the influence of tooth loss and soft diet on the alveolar bone turnover during the growth period. Three-week-old Wistar rats were randomly divided into the following three groups: Hard diet group (rats raised on solid standard diet), Powder diet group (rats raised on powdered standard feed diet), and Extraction group (rats raised on powdered standard diet with maxillary molars extraction). BV, BMC, and BMD in the cancellous bone of M1 were measured using micro-CT analysis. To analyze the histological bone turnover, we prepared non-decalcified thin sections of alveolar cancellous bone when rats were 20 weeks old. On three-dimensional constructed images, the experimental groups (the Powder diet and Extraction groups) showed expansion of the medullary cavity of the interradicular septum of the first molar compared to controls (the Hard diet group). BV, BMC, and BMD were significantly lower in the experimental groups, with the difference from controls being greater in the Extraction group. On histomorphometric analysis, the bone mass parameters, bone formation parameters, and bone mineralization parameters were significantly lower in the experimental groups compared to controls. The bone resorption parameters were significantly higher in the experimental groups. From this study, we found that soft diet and tooth loss might worsen the bone microstructure, reduce osteogenesis, and promote bone resorption in alveolar bone.
基金2020 Youth Training Fund Project of the First Affiliated Hospital of Hainan Medical University(No.202010)
文摘Objective:To investigate the effects of chronic sleep deprivation(CSD)on bone microstructure and peak bone mass(PBM)in SD rats.Methods:Twenty-four SD rats were randomly divided into CSD group and control group.In the CSD group,a CSD model was established using a new sleep deprivation instrument for rats and mice,and intervened for 5 weeks.Bone turnover markers including P1NP and CTX-1 before and after the experiment were observed.After the experiment,the left femur were scanned by Micro-CT,and the cortical bone and bone trabecula were three-dimensionally reconstructed,respectively.The bone mineral density(BMD)and relevant parameters were detected.Results:CT images of the femur(proximal ends)showed significant trabecular loss in CSD rats.Trabecular parameters including bone volume fraction(BV/TV),trabecular number(Tb.N)and trabecular separation(Tb.Sp)in the CSD group were all lower than those in the control group.The bone cortex of the middle segment of the femur and tibia in CSD rats was also lower than that in the control group.The parameters of bone cortex including total tissue area(Tt.Ar),cortical bone area(Ct.Ar)and cortical bone thickness(Ct.Th)in the CSD group were significantly lower than those in the control group(P<0.01).After chronic CSD,BMD of both bone trabecula and bone cortex of the femur was lower,while the corresponding P1NP and CTX-1 were significantly higher than those in the control group.Conclusion:Sleep plays an important role in PBM formation.CSD accelerates bone turnover and thus significantly reducing PBM in SD rats.
基金National Natural Science Foundation of China(39770930)
文摘Objective： To observe the effects of Bushen Zhuanggu Formul on intedeukin 6 （IL-6） level and bone metabolism of the ovariectomized rats, and to explore the possible mechanism of preventing and treating postmenopausal osteo porosis by traditional Chinese Formul. Methods： SD rats were randomly divided into 4 groups： normal control group （N）, ovariectomized control group （OVX）, estrogen-treated group （OVX＋E） traditional and Chinese medicine-treated group （OVX＋ CM）. After treaanent, IL-6 levels in rat bone tissue media and serum were examined by ELISA. The proximal tibias（PTM） of rats were undecalcified for quantitative bone histomorphometry. Results： Compared with OVX group, both Bushen Zhuanggu medicine and estrogen decreased IL-6 level in rat bone tissue media. However, the effects of Bushen Zhuanggu Formul were weaker than those of estrogen. Furthermore, Bushen Zhuanggu Formul and estrogen produced a reduction in bone turnover by inhibiting bone formation and bone resorption at the same time. Conclusion： Bushen Zhuanggu Formul prevents ovariectomic bone loss by inhibiting IL-6 production in rat bone tissues.
文摘The effects of childhood masticatory function loss and soft foods on the mandibular condyle have been the subject of much research. However, the corresponding bone turnover is not fully understood. The purpose of the present study was to clarify the effects of a lack of teeth and a soft food diet during the growth period on bone turnover in the mandibular condyle. We divided 3-week-old Wistar rats into the following three groups: 1) Extraction group: The maxillary molars were extracted at the age of 4 weeks, and animals were fed powdered standard feed. 2) Powder group: Animals were fed powdered standard feed without tooth extraction. 3) Control group: Animals were fed solid standard feed without tooth extraction. Non-decalcified thin-slice specimens of sagittal sections of the mandibular condyle were obtained at the age of 20 weeks for histological analysis. We used micro-CT analysis and bone histomorphometry to measure bone volume (BV), bone mineral content (BMC), bone mineral density (BMD), bone microstructure, bone resorption, and osteogenesis in the mandibular condyle, and we compared the results among groups. In the extraction and the powder groups, we found deformation and disruption of the arrangement of chondrocytes, coagulation of chondrocytes, and duplication of the tidemark in the cartilage. We also found an increase in multinuclear osteoclasts in the cancellous bone. We found a reduction in BV, BMC, and BMD in the extraction and powder groups compared to the control group, as well as a reduction of bone volume, a lowering of osteogenesis parameters, and an increase in bone resorption parameters in the secondary cancellous bone. These results suggest that a lack of teeth and a soft food diet during the growth period cause a decline in bone microstructure, a decrease in osteogenesis, and an increase in bone resorption.
文摘Objective To Investigate stress adaptability of freeze-dried bone allograft.Methods Cortical and cancellous allograft were transplanted to each side of the midshaft diaphyseal ulna in two groups of 28 animals.The left transplanted allograft was free from fixation and bore a normal physiological lcad,while the right transplanted allograft was protected from loading by a simple external fixator and bore less load.Animals were sacrificed at the 2nd,4th,8th,16th week after transplantation and specimens were taken out for bone histomorphometry studies and analysis of collagen gene expression by in situ Cdna-Mrna hybridization.Results Labeled surface(LS)and bone mineral apposition rate(MAR)of the normally loaded graft-host bone interface were significantly higher than that of the less loaded side at the 4th,8th,16th week after transplantation.Parameters reflecting the internal repair process of the allograft,such as LS in cortical and cancellous bone or MAR in cortical bone of the normally loaded side were significantly higher than those of the less loaded side at the 16th week after transplantation.The result of in situ hybridization indicated that more osteoblast-like cells expressing the type Ⅰ collagen gene were found in the interface or interior of normally loaded grafts.Conclusion The stimulus of physiologic load can accelerate the early union of allograft-host bone interface and later new bone creep substitution to the necrotic allograft.
