Objective To investigate the effects of body weight and length of SD rats on the carotid artery balloon injury-induced vascular stenosis model in order to provide a reference for replicating an ideal vascular stenosis mod-el.Methods Male rats were divided into three groups based on body weight and length.The CONQUEROR? SC PTCA balloon catheter was employed,with a fixed balloon inflation volume of 0.2 mL to induce injury in the left common carotid artery,while the right side served as a control.As soon as surgery operation,one rat from each group was selected for Evans Blue dye verification.Fourteen days later,the injured and contra lateral common ca-rotid arteries from remaining rats were harvested for HE staining to check the extent of stenosis.Based on these find-ings,six rats within the optimal range of body weight and length were selected for further validation.Results Rats with body weights ranging from 280 to 380 g(corresponding body lengths of 21.0-26.5 cm)underwent balloon catheter injury,resulting in endothelial detachment and varying degrees of stenosis in the common carotid artery.In rats weighing 280-300 g(body lengths of 21.0-22.5 cm)had severe stenosis or occlusion of the common carotid artery with thrombosis.In rats weighing 320-340 g(body lengths of 23.0-24.5 cm),the internal and external elastic plates of the common carotid artery were ruptured and the vascular morphology was abnormal.Conversely,rats weighing 360-380 g(body lengths of 25.0-26.5 cm)did not show any ruptured elastic laminae or thrombus formation in the common carotid artery,and the extent of vascular stenos in rats with a body weight of 360 g was moderate and uniform.The results of the repeated validation experiments were consistent.Conclusions Rats with a body weight range of 360 g(corresponding body length of 25.0-26.5 cm)are suitable for development of an ideal vascular stenosis model.

Percutaneous coronary intervention(PCI)has been widely applied in the clinical treat-ment of coronary atherosclerotic heart disease and achieved good therapeutic effects.However,vascu-lar restenosis caused by postoperative vascular re-modeling still needs attention,which seriously af-fects the long-term efficacy of PCI.The prevention of vascular restenosis is of great significance for cardiovascular diseases.Traditional Chinese medi-cine natural products,with their characteristics of multiple targets,low toxicity and high safety,have attracted increasing attention in recent years.More and more studies have found that traditional Chi-nese medicine natural products have the effect of preventing and treating vascular restenosis and can effectively control its occurrence and development.This article reviews the effects and mechanisms of flavonoids,alkaloids,terpenoids and glycosides,polysaccharides and polyphenols and other tradi-tional Chinese medicine natural products in pre-venting vascular restenosis,and analyzes and sum-marizes the differences in the effects and mecha-nisms of various natural products,providing new ideas for the development of safe and effective drugs to prevent vascular restenosis.

Percutaneous coronary intervention(PCI)has been widely applied in the clinical treat-ment of coronary atherosclerotic heart disease and achieved good therapeutic effects.However,vascu-lar restenosis caused by postoperative vascular re-modeling still needs attention,which seriously af-fects the long-term efficacy of PCI.The prevention of vascular restenosis is of great significance for cardiovascular diseases.Traditional Chinese medi-cine natural products,with their characteristics of multiple targets,low toxicity and high safety,have attracted increasing attention in recent years.More and more studies have found that traditional Chi-nese medicine natural products have the effect of preventing and treating vascular restenosis and can effectively control its occurrence and development.This article reviews the effects and mechanisms of flavonoids,alkaloids,terpenoids and glycosides,polysaccharides and polyphenols and other tradi-tional Chinese medicine natural products in pre-venting vascular restenosis,and analyzes and sum-marizes the differences in the effects and mecha-nisms of various natural products,providing new ideas for the development of safe and effective drugs to prevent vascular restenosis.

BACKGROUND: Neuropeptides, a kind of endogenous active substance in nerve tissues, can modulate physiological functions of multiple body systems.OBJECTIVE: To observe the effects of vascular bundles or sensory nerve tracts implanted into tissue-engineered bone for rabbit large bone defects on the expression levels of calcitonin gene-related peptide (CGRP) and neuropeptide-Y.METHODS: Fifty-four New Zealand rabbits were enrolled to make model of large bone defects, and then, the animal models were randomly divided into three groups, including sensory nerve tract, vascular bundle, and control groups (n=18 per group), followed by implanted with sensory nerve tracts, vascular bundle, and tissue-engineered bone without sensory tracts or vascular bundle, respectively. The defected bone received gross and Masson staining at 4, 8 and 12 weeks after modeling, to compare the expression levels of CGRP and neuropeptide-Y in each group.RESULTS AND CONCLUSION: mRNA expression levels of CGRP and neuropeptide-Y in the sensory nerve tract and vascular bundle groups were significantly higher than those in the control group at different time points after modeling (P < 0.05). mRNA expression levels of CGRP and neuropeptide-Y in the tissue-engineered bone began to be increased and peaked at the 8th week, and then decreased (P < 0.05), which were the lowest at the 4th week (P < 0.05).Immunohistochemical staining results showed that CGRP was mainly found in the bridge, periosteum of newly born bones and around blood vessels; while neuropeptide-Y mainly localized in the medullary cavity and around blood vessels. These results indicate that the implantation of vascular bundle and sensory nerve tracts for bone defects can upregulate the expression levels of CGRP and neuropeptide-Y, and promote bone repair. However, sensory tract implantation may cause sensory impairment; thereafter, vascular bundle implantation is more suitable for ideal tissue-engineered construction to meet physical requirements.

Objective To explore whether the respective implantation of vascular bundles and sensory nerve tracts into a tissue-engineered bone will affect the expression of CGRP (Calcitonin gene related peptide) and its receptor. Methods Fifty-four New Zealand rabbits were randomly divided into 3 even groups for implantation of sensory nerve tracts (group A),implantation of vascular bundles (group B),and a control group of simple tissue-engineered bone (group C) . Animals were sacrificed 4,8,12 weeks after implantation,respectively. Masson staining was conducted to observe the process of bone formation and re-molding. CGRP and CGRPR-1 expressions in the new bone were measured by immunohistochemistry and Real-time PCR at 4,8 and 12 weeks after implantation. Results At all time points,the CGRP and CGRPR-1 expressions in groups A and B were significantly higher than in group C (P<0.05),and those in group A were higher than in group B too (P<0.05) . Over time,the expressions of CGRP and CGRPR-1 mRNA in each group in the new bone tissue were gradually reduced after an initial increase. The neuropeptide expression at the 8th week was higher than those at the 4th and 12th weeks. The neuropeptide expression at the 4th week was the lowest. The expression of CGRP was mainly localized in the periphery of newly generated bone,periosteum and the blood vessels. The expression of CGRPR-1 was mainly localized in the periphery of osteoblasts. Conclusions Implantation of either vascular bundles or sensory nerve tracts can promote neuropeptide secretion. The vascular bundle implantation may result in higher expressions of CGRP and CGRPR-1 than sensory nerve tract implantation.

Objective To investigate whether tissue engineered bone with implanted vascular bun-dles can up-regulate release of vascular endothelial growth factor (VEGF) in models of femoral defect in rabbits.Methods Thirty-two rabbits were randomized into 2 even groups.In both groups, a segmental bone defect of 15 mm in length was made at the left femur before a tissue engineered bone was inserted into the defect.In the experimental group, a femoral vascular bundle was implanted into the tissue engineered bone.In the control group, there was no vascular implantation.At 2, 4, 8, and 12 weeks after implantation, samples were taken to determine new bone formation by histology and expression level of VEGF by immuno-histochemistry.Results The new bone formation was significantly higher in the experimental group at the end of 4, 8, and 12 weeks(P < 0.05) .The expression level of VEGF in the experimental group was also significantly higher than in the control group at all time points after operation, and the expression of VEGF peaked at 4 weeks.Conclusion Tissue engineered bone with vascular bundle implanted can up-regulate VEGF release in models of femoral defect in rabbits.