Alveolar bone loss with microarchitecture changes in aged rat / Pérdida ósea alveolar con alteraciones en la microarquitectura en ratas envejecidas

SUMMARY: The aim of the present study was to evaluate the changes of alveolar bone in aged rats. The mandibles of the 4- month and 22-month aged rats were scanned by micro-CT. After the reconstruction of the alveolar bone,the distance between the cemento enamel junction (CEJ) and the alveolar bone crest (ABC) was measured. The micro architectures of the inter-radicular alveolar bone were analyzed. The 22-month rats experienced the reduction in alveolar crest height in the buccal side and the lingual side, and significant increase in alveolar bone loss compared with the 4-month rats. The 22-month rats had a porous microarchitecture, the trabecular arrangement was obviously dissociated with the expanded inter-bone spaces of marrow, and the bone histomorphometry analysis showed the decreased bone volume/tissue volume and trabecular thickness in the 22-month rats. These results suggest that alveolar bone loss and alveolar trabecular bone deterioration might contribute to the weakening of molar support in the elderly.

RESUMEN: El objetivo del presente estudio fue evaluar los cambios del hueso alveolar en ratas envejecidas. Las mandíbulas de las ratas de 4 y 22 meses se escanearon mediante micro-TC. Después de la reconstrucción del hueso alveolar, se midió la distancia entre la unión cementoesmalte (CEJ) y la cresta ósea alveolar (ABC). Se analizaron las microarquitecturas del hueso alveolar interradicular. Las ratas de 22 meses experimentaron la reducción de la altura de la cresta alveolar. en el lado bucal y lingual, y un aumento significativo en la pérdida de hueso alveolar en comparación con las ratas de 4 meses. Las ratas de 22 meses tenían una microarquitectura porosa, la disposición trabecular estaba obviamente disociada con los espacios interóseos expandidos de la médula y el análisis de histomorfometría ósea mostró una disminución del volumen óseo / volumen tisular y del grosor trabecular en las ratas de 22 meses. Estos resultados sugieren que la pérdida ósea alveolar y el deterioro del hueso trabecular alveolar podrían contribuir al debilitamiento del soporte molar en los ancianos.

Consideraciones Metodológicas en el Estudio Histomorfométrico del Hueso Interradicular de los Primeros Molares Inferiores de Ratas Wistar / Methodological Considerations in the Histomorphometric Study of the Interradicular Bone of the First Lower Molars of Wistar Rats

El objetivo fue evaluar el volumen óseo BV/TV (%) del hueso interradicular en ratas Wistar: A) en relación a la edad; B) en relación a la zona de estudio en animales de la misma edad. Se utilizó Grupo A) 15 ratas Wistar hembras de 6 (I), 10 (II) y 14 (III) semanas, Grupo B) 9 ratas Wistar macho de 8 semanas. Tras la eutanasia, se extrajeron los maxilares inferiores y se procesaron histológicamente para obtener cortes mesio-distales del primer molar inferior coloreados con H.E. Sobre microfotografías digitales se evaluó el BV/TV (%). El análisis estadístico se realizó en A) mediante ANOVA y Bonferroni test y en B) se calculó el rango (R). Los resultados en A) el BV/TV (%) aumenta significativamente con la edad de los animales; en B) se encontró que el BV/TV (%) varía hasta un 20% si se considera el volumen total y este rango disminuye a 8.3% al estudiar su mitad coronal. En conclusión, el BV/TV (%) del hueso interradicular del primer molar inferior de ratas Wistar varía considerablemente con la edad de los animales y en animales de una misma edad -según se considere evaluar todo el hueso interradicular del espacio alveolar o la mitad superior del mismo-. Los resultados de este trabajo recomiendan emplear animales de la misma edad y realizar mediciones histomorfométricas empleando la mitad coronal de dicho hueso, especialmente en los diseños de periodontitis experimental (AU)

Effects of drynaria total flavonoids on mandible structure, serum E2 and OPG/RANKL balance in ovariectomized rats / 西安交通大学学报(医学版)

Objective: To explore the effects of drynaria total flavonoids on serum estrogen (E2) level, OPG/RANKL balance and bone microarchitecture of mandible in a rat model of bone loss induced by ovariectomy. Methods: We randomly divided 40 three-month-old female Sprague-Dawley rats into 5 groups (n=8 per group): sham-operation group (Sham), ovariectomized group (OVX), low-dose drynaria total flavonoids group (GB-L), high-dose drynaria total flavonoids group (GB-H) and estradiol valerate group (EV). The mandibular osteoporosis model was established by removing the rats' ovaries. After 12 weeks the rats were killed, and the serum estrogen levels were measured. OPG and RANKL were detected using ELISA method. Therapeutic effect of drynaria total flavonoids was observed by pathomorphology and histomorphometry of the mandibular molar sections. Results: Compared with those in the sham group, the mandible of rats in OVX group was loosely changed, the level of E2 decreased significantly (P<0.001), and OPG/RANKL decreased significantly (P<0.001). Compared with OVX group, the mandible microstructure of rats in EV group got a good repair, while the serum E2 level and OPG/RANKL increased significantly (both P<0.001). Compared with OVX group, the percentage of trabecular bone (%Tb.Ar) and OPG/RANKL increased in all the GB groups (P<0.001, P=0.029), (P<0.001, P=0.007), while GB-H group also had increased thickness of trabecular bone (Tb.Th) and serum OPG levels (P=0.019, P<0.001), reduced trabecular spacing (Tb.Sp)(P=0.001), but no effect on serum E2 level (P=0.432, P=0.459). Conclusion: Drynaria total flavonoids can inhibit the destruction of the mandibular trabecular structure, thus slowing down the mandibular resorption process. However, they cannot improve E2 concentration. The mechanism is realized by adjusting the balance of OPG/RANKL.

Bone biopsy in nephrology practice / Biópsia óssea na prática nefrológica

Abstract Renal osteodystrophy (ROD), a group of metabolic bone diseases secondary to chronic kidney disease (CKD), still represents a great challenge to nephrologists. Its management is tailored by the type of bone lesion - of high or low turnover - that cannot be accurately predicted by serum biomarkers of bone remodeling available in daily clinical practice, mainly parathyroid hormone (PTH) and alkaline phosphatase (AP). In view of this limitation, bone biopsy followed by bone quantitative histomorphometry, the gold-standard method for the diagnosis of ROD, is still considered of paramount importance. Bone biopsy has also been recommended for evaluation of osteoporosis in the CKD setting to help physicians choose the best anti-osteoporotic drug. Importantly, bone biopsy is the sole diagnostic method capable of providing dynamic information on bone metabolism. Trabecular and cortical bones may be analyzed separately by evaluating their structural and dynamic parameters, thickness and porosity, respectively. Deposition of metals, such as aluminum and iron, on bone may also be detected. Despite of these unique characteristics, the interest on bone biopsy has declined over the last years and there are currently few centers around the world specialized on bone histomorphometry. In this review, we will discuss the bone biopsy technique, its indications, and the main information it can provide. The interest on bone biopsy should be renewed and nephrologists should be capacitated to perform it as part of their training during medical residency.

Resumo A osteodistrofia renal (OR), um grupo de doenças ósseas metabólicas secundárias à doença renal crônica (DRC), ainda representa um grande desafio para os nefrologistas. Seu manejo é individualizado de acordo com o tipo de lesão óssea - de alto ou baixo remodelamento - cujo diagnóstico não pode ser prevista com precisão pelos biomarcadores séricos de remodelação óssea disponíveis na prática clínica diária, principalmente o paratormônio (PTH) e a fosfatase alcalina (FA). Em vista dessa limitação, biópsia óssea seguida de histomorfometria óssea quantitativa, método padrão-ouro para o diagnóstico de OR, ainda é considerado um procedimento de grande importância. A biópsia óssea também é recomendada na avaliação da osteoporose em indivíduos com DRC, a fim de auxiliar na escolha do melhor medicamento anti-osteoporótico. É importante observar que a biópsia óssea é o único método diagnóstico capaz de proporcionar informações dinâmicas sobre o metabolismo ósseo. Os ossos trabecular e cortical podem ser analisados separadamente por meio da avaliação de seus parâmetros estruturais e dinâmicos, espessura e porosidade, respectivamente. A deposição óssea de metais como alumínio e ferro também pode ser detectada. Apesar de suas características singulares, o interesse pela biópsia óssea diminuiu nos últimos anos. Poucos centros em todo o mundo são especializados em histomorfometria óssea. A presente revisão discute a técnica de biópsia óssea, suas indicações e as principais informações que ela pode oferecer. O interesse pela biópsia óssea deve ser renovado e os nefrologistas devem ser capacitados a realizá-la durante o período de residência médica.

Biometric, histomorphometric, and biochemical profile in atorvastatin calcium treatment of female rats with dexamethasone-induced osteoporosis / Perfil biométrico, histomorfométrico e bioquímico no tratamento com atorvastatina cálcica de ratas com osteoporose induzida com dexametasona

ABSTRACT Objective: To assess the effects of atorvastatin calcium in the treatment of dexamethasone-induced osteoporosis. Methods: Osteoporosis induction consisted of the administration of an intramuscular dose of 7.5 mg/kg of body weight of dexamethasone, once a week for four weeks, except for the control animals (G1). The animals were divided into the following groups: G1 (control group without osteoporosis), G2 (control group with untreated osteoporosis), G3 (control group with osteoporosis treated with sodium alendronate 0.2 mg/kg) and G4 (group with osteoporosis treated with atorvastatin calcium 1.2 mg/kg). Serum alkaline phosphatase, bone alkaline phosphatase, and biometric and bone histomorphometric assessments were performed after 30 and 60 days of treatment onset. Results: In relation to the biometric and histomorphometric analyses, at 60 days of treatment, G4 presented bone density (Seedor index), bone trabecular density, and cortical thickness of 0.222 ± 0.004 g/cm, 59.167 ± 2.401%, and 387,501 ± 8573 µm, respectively, with a positive and statistically significant difference (p < 0.05), in relation to G2. At 30 and 60 days of treatment, G4 presented statistically significant serum levels of alkaline phosphatase alkaline phosphatase (p < 0.05) that were higher than all groups (7.451 ± 0.173 µg/L and 7.473 ± 0.529 µg/L, respectively). Conclusion: Treatment with atorvastatin calcium demonstrated the ability of this drug to increase osteoblastic activity and bone tissue repair activity, acting differently from alendronate sodium, which demonstrated predominantly antirebsorptive activity.

RESUMO Objetivo: Avaliar os efeitos da atorvastatina cálcica no tratamento da osteoporose induzida com dexametasona. Métodos: A indução da osteoporose consistiu na administração de dexametasona na dose de 7,5 mg/kg de peso corporal, por via intramuscular, uma vez por semana durante quatro semanas, à exceção dos animais do grupo controle (G1). Os animais foram distribuídos nos seguintes grupos: G1 (grupo controle sem osteoporose), G2 (grupo controle com osteoporose sem tratamento), G3 (grupo controle com osteoporose tratado com alendronato de sódio 0,2 mg/kg) e G4 (grupo com osteoporose tratado com atorvastatina cálcica 1,2 mg/kg). Após 30 e 60 dias do início do tratamento dos animais, foram feitas as dosagens dos níveis séricos de fosfatase alcalina, fosfatase alcalina óssea, avaliação biométrica e histomorfométrica óssea. Resultados: Em relação às análises biométricas e histomorfométricas, aos 60 dias de tratamento o G4 apresentou densidade óssea (índice Seedor), densidade trabecular óssea e espessura da cortical de 0,222 ± 0,004 g/cm, 59,167 ± 2,401% e 387,501 ± 8,573 µm, respectivamente, com diferença positiva, estatisticamente significativa (p < 0,05), em relação ao grupo G2. Aos 30 e 60 dias de tratamento, o G4 apresentou níveis séricos de fosfatase alcalina óssea estatisticamente significativos (p < 0,05) e superiores a todos os grupos (7,451 ± 0,173 µg/L e 7,473 ± 0,529 µg/L, respectivamente). Conclusão: O tratamento com atorvastatina cálcica demonstrou a capacidade desse fármaco de aumentar a atividade osteoblástica e a atividade reparadora tecidual óssea, atuar de forma diferente do alendronato de sódio, que demonstrou atividade preponderantemente antirreabsortiva.

Histomorphometric reference data of transiliac bone biopsy in children from 8 to 17 years old / Datos histomorfométricos de referencia de la biopsia ósea en niños de 8 a 17 años

Abstract: Background: Histomorphometric analysis of bone samples is a key tool for studying bone metabolism; however, only a few pediatric reference data exist. The aim of the present study is to report more reference data and to investigate if histomorphometric differences exist between age and gender. Methods: We obtained 19 transiliac bone samples previously marked with tetracycline, from children between 8 and 17 years (13 were male), with normal blood test results and urine biochemical bone markers. We evaluated bone histomorphometric parameters using a digitalizing table with osteomeasure to obtain normative data of means and standard deviations, as well as median and range. Due to the small sample, a Monte Carlo simulation was applied. Structural, static, dynamic, and resorptic histomorphometric parameters were evaluated by age and gender following the American Society for Bone and Mineral Research recommendations. Results: Bone volume (in the older children) and mineral apposition rate (in the younger children), the eroded surface (in boys), and the new bone wall thickness (in girls) were significantly increased. On the trabecular area of mineralization front, the modeling and the remodeling bone formation were similar (16 and 18%). The rest of the histomorphometric bone parameters by age and gender showed no significant difference. Conclusion: In healthy children, these bone histomorphometric findings, with these techniques and for this ages could be used as reference values.

Resumen: Introducción: El análisis histomorfométrico del tejido óseo para el estudio de las enfermedades metabólicas óseas, cuando se correlacionan los hallazgos clínicos, sigue siendo la herramienta con mayor sensibilidad y especificidad para la mayoría de los diagnósticos. En los niños existen pocos reportes histomorfométricos del tejido óseo metabólico normal, por lo que nuestro propósito es reportar más datos de referencia e investigar si hay diferencias histomorfométricas entre edades y sexos. Métodos: Estudio realizado en 19 niños de 8 a 17 años (13 masculinos) sin anomalías clínicas ni bioquímicas evidentes. Se tomaron muestras de tejido óseo transilíaco marcadas con tetraciclina. Se obtuvieron medias, desviaciones y rangos histomorfométricos totales, y correlación por edad y sexo, siguiendo las recomendaciones para la histomorfometría de la American Society for Bone and Mineral Research. Se realizó una simulación Montecarlo. Resultados: El volumen óseo (en niños mayores), la velocidad de agregación del mineral (en niños menores), la erosión trabecular periférica (en niños) y el grosor de la pared ósea nueva (en niñas) exhibieron aumentos significativos. En el área trabecular del frente de mineralización, el modelado y el remodelado de la formación ósea fueron similares (16 y 18%). El resto de los parámetros histomorfométricos óseos no mostraron diferencias significativas. Conclusiones: Estos hallazgos histomorfométricos del tejido óseo de niños normales con estas técnicas y para estas edades pueden ser utilizados como valores de referencia.

Therapeutic effect of gastrin on steroid-associated osteonecrosis in rats / 上海交通大学学报（医学版）

Objective: To investigate therapeutic effect of gastrin on steroid-associated osteonecrosis (SAON) in rat model. Methods: Twenty-four SD rats were randomly divided into three groups i.e. normal control group (normal group), SAON control group (SAON group) and SAON treatment group (treatment group). SAON group and treatment group were intravenously injected with lipopolysaccharide 1 time per day (600 μg/kg) for 2 d and meanwhile intramuscularly injected with methylprednisolone 1 time per day (50 mg/kg) for 3 d. Normal group was injected with normal saline of the same volumns. After steroid injections, treatment group was injected with gastrin 1 time per day (800 μg/kg) for 14 d, while SAON group was injected with normal saline of the same volumns. After the treatment, bone trabeculas below femoral head growth plate were dissected in the rats for bone histology. Hematoxylin-eosin (H-E) staining, immunohistochemistry, fluorescence staining and Goldner's trichrome staining were applied in this study. Results: SAON model in rats was successfully established. The result of H-E staining showed that compared with SAON group, thrombus area, number and area of fat cells in the bone marrows of treatment group obviously decreased (all P<0.05). Immunohistochemistry showed that osteogenic transcription factor (Sp7) positive cells in treatment group were more than those in SAON group (P<0.01). Compared with SAON group, osteoid length and area (Goldner's trichrome staining), and bone formation rate and bone mineralization deposition rate (fluorescence staining) all significantly increased in treatment group (all P<0.01). Conclusion: Gastrin can effectively treat SAON in rats by suppressing thrombus and lipid formation and enhancing boneformation.

Therapeutic effect of gastrin on steroid-associated osteonecrosis in rats / 上海交通大学学报（医学版）

Objective·To investigate therapeutic effect of gastrin on steroid-associated osteonecrosis (SAON) in rat model. Methods·Twenty-four SD rats were randomly divided into three groups i.e. normal control group (normal group), SAON control group (SAON group) and SAON treatment group (treatment group). SAON group and treatment group were intravenously injected with lipopolysaccharide 1 time per day (600 μg/kg) for 2 d and meanwhile intramuscularly injected with methylprednisolone 1 time per day (50 mg/kg) for 3 d. Normal group was injected with normal saline of the same volumns. After steroid injections, treatment group was injected with gastrin 1 time per day (800 μg/kg) for 14 d, while SAON group was injected with normal saline of the same volumns. After the treatment, bone trabeculas below femoral head growth plate were dissected in the rats for bone histology. Hematoxylin-eosin (H-E) staining, immunohistochemistry, fluorescence staining and Goldner's trichrome staining were applied in this study. Results·SAON model in rats was successfully established. The result of H-E staining showed that compared with SAON group, thrombus area, number and area of fat cells in the bone marrows of treatment group obviously decreased (all P<0.05). Immunohistochemistry showed that osteogenic transcription factor (Sp7) positive cells in treatment group were more than those in SAON group (P<0.01). Compared with SAON group, osteoid length and area (Goldner′s trichrome staining), and bone formation rate and bone mineralization deposition rate (fluorescence staining) all significantly increased in treatment group (all P<0.01). Conclusion·Gastrin can effectively treat SAON in rats by suppressing thrombus and lipid formation and enhancing bone-formation.

Effects of Huangqi Powder on femur and tibia in rats with glucocorticoid-induced osteoporosis / 中成药

AIM To study the influence of Huangqi Powder (Puerariae lobatae Radix,Astragali Radix,Mori Cortex) on femur and tibia in rats with glucocorticoid-induced osteoporosis (GIOP).METHODS Thirty one-month-old male SD rats were divided into three groups by randomized block design,which were control group (normal saline),prednisone group (3.5 mg/kg prednisone acetate),Huangqi Powder group (clinical adult dosage).Experimental test was maintained for one hundred and twenty days.Double fluorochrome labeling with calcein was performed before necropsy;bone resorption and bone formation index were determined by using blood serum;the femur structural and material mechanics were analyzed by using bone biomechanics method.The cancellous bone of proximal tibial and the cortical bone of tibial shaft static parameter and dynamic parameter were analyzed by bone histomorphometry method.RESULTS Huangqi Powder had no obvious improving effects on bone biomechanics and bone static parameter,but could increas the area,width and number of the proximal tibia bone trabecular.Mark perimeter percentage and mineralization rate of deposition could be increased.CONCLUSION Huangqi Powder can significantly increase proximal tibia cancellous bone mass and enhance bone trabecula structure of glucocorticoid-induced osteoporosis rats.

Effects of ginseng flower bud on bone metabolism in rats induced by D-galactose / 中国药理学通报

Aim To investigate the skeletal effects of ginseng flower bud(GF)on osteopenia induced by D-galactose using histomorphometry and biomechanical properties.Methods Fifty three-month-old male Sprague-Dawley rats were randomly divided into five groups.Rats in NS group(NS)were treated with NS(5 mL·kg-1·d-1)by subcutaneous injection and daily oral gavage with vehicle as control.Rats in the other four groups were given D-galactose at the dose of 100 mg·kg-1·d-1 by subcutaneous injection.Solvent control was performed between NS and DG: gastric irrigation with distilled water of 10 mL·kg-1·d-1.Other groups were: CP was gastric irrigated with integrated medicine(stanozolol 0.54 mg·kg-1·d-1+piracetam 432 mg·kg-1·d-1),GF(L)with ginseng flower bud of 0.486 g·kg-1·d-1 and GF(H)with ginseng flower bud of 2.43 g·kg-1·d-1 for 14 weeks.The longitudinal proximal tibial metaphyseal(PTM),the fifth lumbar vertebral body(LVB)and tibial shaft(Tx)sections were performed undecalcifiedly and used for bone histomorphometric analysis.858 Mini Bionix materials testing system was used to analyze the biomechanic properties of right femur via three-point bending test.The left femur was dried and assimilated,whose bone calcium(Ca),phosphate(P)content and bone hydroxyproline content were tested.Results Compared with D-glagatose group,in PTM of D-galactose treated rats,the％Tb.Ar was increased both in GF(L)and GF(H)treated groups.While the Tb.Sp was decreased.％Oc.S.Pm and Oc.N/mm decreased in GF(L),and those in GF(H)were decreased as well.In Tx,％Ct.Ar was raised,while％Ma.Ar was decreased in GF(L)and GF(H).The elastic load of femur was increased.Conclusions Compared with DG group,there are significant differences in bone histomorphometry of Tx and PTM in all doses of GF,but no significant changes are detected in hydroxyproline,Ca,and P content of femur.

Effect of simvastatin on bone mass recovery in rats with reloading after tail-suspension / 中国比较医学杂志

Objective To observe the changes of bone mass in reloaded rats after tail-suspension,and the effect and mechanism of simvastatin on this process.Methods Twenty-four 5-month old rats were divided into 4 groups of 6 animals in each group: Control (CL) group without tail-suspension,unloaded (UL) group with tail-suspension for 6 weeks,other 12 rats received tail-suspension for 3 weeks,then reloaded for subsequent 3 weeks (UL+RL) or combined with simvastatin treatment (UL+RL+SIM) at a dose of 10 mg/kg/d.All rats were sacrificed 6 weeks later,and the left femur was used for examination of bone mineral density,left tibia was used for bone histomorphometry analysis,the right femur and tibia were harvested for biomechanical test,and expression levels of type I collagen by real-time PCR and Western blot,respectively.Results 1.BMD of the CL group was significantly higher than those of the other three groups (P<0.05),and was markedly lower than those in the UL+RL and UL+RL+SIM groups (P<0.05).2.The bone histomorphometry showed that BV/TV in the CL group was significantly higher than those in the other 3 groups,and the UL+RL and UL+RL+SIM groups showed a significantly higher BV/TV than that of UL group (P<0.05).The Tb.Th was significantly higher in the CL group than in the UL group.The Tb.Sp in the CL group was significantly lower than those in the other 3 groups (P<0.05).The UL+RL and UL+RL+SIM groups showed significantly lower Tb.Sp than that of the UL group (P<0.05).3.Biomechanical test showed that the maximal load and elastic modulus in the CL groups were significantly higher than those of the other three groups (P<0.05).4.Real-time PCR showed that no significant difference in the mRNA expression level of Col I was found between any two groups.5.Western blot showed that the IOD of Col I is significantly lower than that in the CL group.Conslusions Bone loss,destruction of trabecular bone micro-architecture and biomechanical properties and reduction of type 1 collagen are present in tail-suspension treated rats,which are partially restored after reloading,and this recovery process is not enhanced by simvastatin treatment.

Effects of 1.8 mT sinusoidal electromagnetic fields of different frequencies on bone mineral density and bone histomorphometry of young rats / 生物工程学报

To study the effects of different frequency sinusoidal electromagnetic fields on the bone mineral density and bone histomorphometry of SD young rats, and to screen suitable electromagnetic field frequency. In total 32 female SD rats of 8 weeks old were randomly divided into 4 groups: control group, 15 Hz group, 30 Hz group and 45 Hz group. Except for the control group, rats in experimental groups were treated with corresponding frequency of 1.8 mT sinusoidal electromagnetic field 90 minutes every day. Rats were measured for bone mineral density after 8 weeks by dual energy X-ray absorptiometry. Rats' femur and vertebral bones were measured by analyzing the static and dynamic forms on the right tibia bone for morphometrics. Rat serum was measured to estimate the index of bone formation and bone resorption. Bone mineral density of rats from 15 Hz group and 45 Hz group was higher than that of the control group (P<0.05). Serum osteocalcin level of rats from 15 Hz group and 45 Hz group was higher than that of the control group (P<0.05). Double fluorescence spacing and static parameters of bone tissue in experimental group rat tibia were higher than that of the control group (P<0.05). Our findings imply that 15 Hz and 45 Hz sinusoidal electromagnetic fields can effectively increase bone mineral density in young rats for preventing osteoporosis.

Effects of chronic mild stress on parameters of bone assessment in adult male and female rats / Efeito do estresse moderado crônico sobre parâmetros de avaliação óssea em ratos adultos machos e fêmeas

Osteoporosis is a multifactorial disease of high prevalence and has great impact on quality of life, because the effects on bone structure increase the risk of fractures, what may be very debilitating. Based on the observation that patients with depression have lower bone mineral density than healthy individuals, many studies have indicated that stress could be an aggravating factor for bone loss. This study evaluates the effect of a protocol of chronic mild stress (CMS) on parameters of bone assessment in male and female rats. Five 5-monh-old rats of each sex underwent a schedule of stressor application for 28 days. Stressors included cold, heat, restraint, cage tilt, isolation, overnight illumination, and water and food deprivation. Five rats of each sex were kept under minimum intervention as control group. The animals were weighed at beginning and end of the period, and after euthanasia had their bones harvested. Femur, tibia and lumbar vertebrae were analyzed by bone densitometry. Biomechanical tests were performed in femoral head and diaphysis. Trabecular bone volume was obtained from histomorphometric analysis of femoral head and vertebral body, as well as of femoral midshaft cross-sectional measures. Not all parameters analyzed showed effect of CMS. However, tibial and L4 vertebral bone mineral density and cross-sectional cortical/medullar ratio of femoral shaft were lower in female rats submitted to the CMS protocol. Among male rats, the differences were significant for femoral trabecular bone volume and maximum load obtained by biomechanical test. Thus, it could be confirmed that CMS can affect the balance of bone homeostasis in rats, what may contribute to the establishment of osteopenia or osteoporosis.(AU)

A osteoporose é uma doença multifatorial, de alta prevalência e que tem um grande impacto na qualidade de vida, principalmente porque os efeitos sobre a estrutura do osso aumentam o risco de fraturas, que podem ser muito debilitantes. Com base na observação de que pacientes com depressão têm menor densidade mineral óssea que indivíduos saudáveis​​, muitos estudos têm indicado que o estresse pode ser um fator agravante para a perda óssea. Este estudo avalia o efeito de um protocolo de estresse moderado crônico (EMC) em parâmetros de avaliação óssea em ratos machos e fêmeas. Cinco animais de cada sexo, com cinco meses de idade, foram submetidos a um cronograma de aplicação de estressores durante 28 dias. Os estressores incluídos foram: frio, calor, contenção, inclinação da gaiola, isolamento, iluminação durante a noite e privação de água e ração. Cinco animais de cada sexo foram mantidos com um mínimo de intervenção como grupo controle. Os animais foram pesador no início e no final do período, e após eutanásia tiveram seus ossos coletados. Fêmur, tíbia e vértebra lombar foram analisados por densitometria óssea. Testes biomecânicos foram realizados na cabeça e na diáfise do fêmur. Volume trabecular ósseo foi obtido a partir de análise histomorfométricas da cabeça do fêmur e do corpo vertebral, bem como medidas da seção transversal diáfise femoral. Nem todos os parâmetros avaliados sofreram efeito do protocolo de EMC. No entanto, a densidade mineral óssea da tíbia e da vértebra L4 e a razão osso cortical/medula da seção transversal da diáfise femoral foram menores nas fêmeas submetidas ao protocolo. Entre os ratos machos, as diferenças foram significativas no volume trabecular ósseo da cabeça femoral e na carga máxima obtida no teste biomecânico. Assim, confirma-se que o protocolo de EMC pode afetar o equilíbrio da homeostase óssea em ratos, o que pode contribuir para o estabelecimento de osteopenia ou osteoporose.(AU)

Quantification of Bone Histomorphometric Parameters Using the Weibel Technique in Animals

Bone histomorphometric measurements are required to understand the efficacy of treatment on bone remodelling. Previous studies used the Weibel technique as a quantitative stereological method to determine bone cellular and dynamic changes. However, there was no description on how this technique was applied. This studyaimed to provide a full picture about the utilization of the Weibel technique to measure static and dynamic bone histomorphometric indices. Technical expertise, processing of bone samples, randomization of the trabecular sections and an adequate number of analysed images for each section are required to achieve reliable results with a low possibility of errors.

Effect of Sodium ferulate on glucocorticoid-induced osteoporosis / 中国药理学通报

Aim To study the influence of Sodium fer-ulate ( SF) on bone metabolism in glucocorticoid–in-duced osteoporosis rats. Methods Thirty cases of fe-male Wistar Rats(3-month-old) were divided into con-trol group, model group and SF group ( low-dose group, middle-dose group, high-dose group ) by ran-domized block design. Double fluorochrome labeling with calcein was performed before necropsy. The left tibia was taken for bone histomorphometry. Results In static parameters, the proximal tibia cancellous bone trabecular thickness, trabecular quantity and area ratio were significantly reduced in model group compared with control group;while compared with model group, those were increased in middle and high-dose SF group. Trabecular separation degree was increased in model group compared with control group, while it was decreased in middle and high-dose SF group compared with model group. In dynamic parameters, the calcula-tion parameters of cancellous bone mark perimeter rate and the bone formation rate were increased in model group compared with control group, in middle and high-dose SF group the bone formation rate was in-creased compared with model group. In bone cells, os-teoclast number per mm, osteoblast number per mm, percent osteoblast surface perimeter and percent osteo-clast surface perimeter were increased in model group compared with control group. In growth-plate, the thickness of growth-plate was increased in model group compared with control group. In bone cells and growth-plate there was no statistical significance between treat-ment group and model group. Conclusion This study demonstrates that SF can increase bone mass and im-prove bone structure,which may be related to the im-provement of bone formation. SF is effective for GIOP in rats.

Effect of CoQ10 on cortical bone in cyclophosphamide-treated rats / 中国药学杂志

OBJECTIVE: To investigate the preventive effects of coenzyme Q10 on cortical bone in cyclophosphamide-treated rats and compare CoQ10 with alendronate sodium. METHODS: Thirty-two three-month-old SPF and SD male rats were randomly divided into 4 groups (n=8 per group). Group 1 was treated with vehicle as the control group (CON group). Other groups were treated with cyclophosphamide (4.5 mg·kg-1·d-1) first, and then vehicle (CTX group), alendronate sodium (ALD 1 mg·kg-1·d-1) and CoQ10 (30 mg·kg-1·d-1) once a day for 15 d. At the experimental endpoint, The static and dynamic parameters of left tibia bone grinding by the bone histomorphometry and took the right femur bone biomechanical testing were observated. RESULTS: From bone histomorphometry parameters, cyclophosphamide can inhibit bone formation which make rat cortical bone thinning, bone marrow cavity to expand; reduced bone formation. Coenzyme Q10 can effectively promote bone formation, inhibit bone loss in rats by cyclophosphamide, the effect is better than the positive drug alendronate sodium. Compared with the CON group, biomechanical properties of maximal strength, break strength, break strain and toughness index were decreased significantly, while modulus of rigidity was increased significantly in the CTX group. Compared with the CTX group, the ALD group, only several parameters of the biomechanical properties were significantly improved. In contrast, in the CoQ10 group, the biomechanical properties were significantly improved. CONCLUSION: CoQ10 (30 mg·kg-1·d-1) on the microstructure of CTX rat tibia bone repair capacity better, and the ability to repair bone mass and reduce the risk of hip fracture is also superior ALD.

Effects of saxagliptin and exenatide on humerus cancellous bone of diabetes-induced osteopenia rats / 中国药学杂志

OBJECTIVE: To determine the effects of saxagliptin and exenatide on humerus cancellous bone of diabetes-induced osteopenia rats by histomorphometry. METHODS: Thirty-five Cases of female SD rats were randomly divided into normal group (N group, n=7), control group (C group, n=7), and the remaining rats were used to establish the type 2 diabetic model by combination of high-fat&sugar-diet feeding for 4 weeks and then low-dose streptozotocin injection(STZ, 30 mg·kg-1). After 10 d, the oral glucose tolerance test and the fasting blood glucose were measured, rats with high OGTT(2 h) above 11.1 mmol·L-1 and high FBG above 16.7 mmol·L-1 were divided into model group (M group, n=5), saxagliptin group (G group, n=5) and exenatide group (D group,n=6), and continuously treated for 30 d. The left humerus (proximal humeru metaphometry, PHM) were fixed with 4% paraformaldehyde for 48 h, uncalcified embedded in methyl methacrylate after dehydrated and cleared, and sections were taken for bone histomorphometry after Masson-Goldner Trichrome stained. RESULTS: In PHM, there was no statistical significance between N and C group, the trabecular bone area ratio(BV/TV) and trabecular quantity were significantly decreased (P<0.01) in M group, while the trabecular separation degree was increased, comparing with those in C group (P<0.01), and the trabecular bone area ratio(BV/TV) and trabecular quantity in G and D group were higher (P<0.01) than those of model rats, while the trabecular separation degree was decreased, comparing with those in M group (P<0.01). Cell parameters showed no statistical significance between N and C group, the osteocllast number and percentage of osteocllast surface perimeter were significantly reduced(P<0.05, P<0.01) in M group, while the osteoclast number and percent osteocllast surface perimeter were significantly increased (P<0.01) as compared with those in C group, saxagliptin and exenatide were found to significantly induce osteocllast number (P<0.01) and percentage of osteoblast surface perimeter (G group P<0.05, D group P<0.01), while reduce osteoclast number (P<0.01) and percent osteoblast surface perimeter (P<0.05) compared with M group. In growth-plate, there was no statistical significance between N and C group, the thickness of growth-plate and the diameter of the mast cells were reduced in M groups (P<0.01), while the thickness of growth-plate (P<0.01) and the diameter of the mast cells (P<0.05) were increased in G and D group,compared with M group. CONCLUSION: Therapeutic effects of saxagliptin and exenatide on diabetes-induced osteopenia rats was showed, and the mechanism may be related to the improved growth rate of growth-plate and the changed bone turnover status.

Bone disease in hypoparathyroidism / Doença óssea no hipoparatiroidismo

Hypoparathyroidism is a rare disorder that may be acquired or inherited. Postsurgical hypoparathyroidism is responsible for the majority of acquired hypoparathyroidism. Bone disease occurs in hypoparathyroidism due to markedly reduced bone remodeling due to the absence or low levels of parathyroid hormone. Chronically reduced bone turnover in patients with hypoparathyroidism typically leads to higher bone mass than in age- and sex-matched controls. Whether this increased bone density reduces fracture risk is less certain, because while increased bone mineralization may be associated with increased brittleness of bone, this does not appear to be the case in hypoparathyroidism. Treatment of hypoparathyroidism with recombinant parathyroid hormone may reduce bone mineral density but simultaneously strengthen the mechanical properties of bone.

O hipoparatireoidismo é uma enfermidade rara que pode ser adquirida ou herdada. Dentre as causas adquiridas dessa doença, destaca-se como maior responsável o hipoparatireoidismo pós-cirúrgico. As manifestações ósseas dessa patologia decorrem devido a uma diminuição marcada no remodelamento ósseo causada pela diminuição ou ausência do hormônio da paratireoide. Esse remodelamento ósseo cronicamente reduzido leva a um aumento da massa óssea, evidenciado quando indivíduos com hipoparatireoidismo são comparados a controles de mesma idade e sexo. Entretanto, não se sabe se esse aumento de massa óssea reduz o risco de fratura. Apesar de o aumento da massa óssea estar associado a um aumento da fragilidade óssea em algumas situações, este não parece ser o caso no hipoparatireoidismo. O tratamento com hormônio recombinante da paratireoide pode reduzir a densidade mineral óssea ao mesmo tempo em que melhora as propriedades mecânicas do osso.

The observation and evaluation of bone histomorphometry in three osteoporosis models of mice / 中国药理学通报

Aim To investigate whether D-galactose cause osteoporosis and the difference compared with the osteoporosis induced by ovariectomy, and to deter-mine whether ovariectomy coupled with D-galactose ac-celerated the progress of osteoporosis and whether es-trogen had a preventive effect on these osteoporosis models. Methods Sixty SPF mice were randomly divided into six groups , namely sham-operated group, D-galactose group, OVX group, OVX + D-galactose group, OVX + D-galactose + diethylstilbestrol group and D-galactose + diethylstilbestrol group. Seventy days later, the right tibia was processed with undecal-cified sections for bone histomorphometric analysis. Results Compared with the sham-operated group, %Tb. Ar, Tb. Th and Tb. N decrease by 50. 4%, 25. 4%, 50. 9% ( P <0.01 ) respectively, Tb. Sp in-creased by 169. 4% (P <0.05), Oc. pm, Oc. No. ,%Oc. S, Oc. N/mm which reflected bone absorption significantly increased ( P < 0.01 ) , and % L. Pm, MAR, BFR/TV, BFR/BV, BFR/BS which reflected bone formation significantly decreased ( P <0.01 ) in OVX group. %Tb. Ar decreased by 30. 4% in D-ga-lactose group, but there was no statistically significant difference. However, the four parameters reflected the bone absorption in D-galactose group increased signifi-cantly ( P<0.05 ) , while the four parameters reflected bone formation decreased significantly ( P < 0.05 ) . OVX+D-galactose group has obvious performance of osteoporosis, but there was no significant difference compared to OVX group, nor to D-galactose group. Estrogen had significant preventive effect on related pa-rameters of osteoporosis induced by D-galactose and o-variectomy coupled with D-galactose. ConclusionsOsteoporosis model of mice can be established by OVX, D-galactose and OVX +D-galactose. Estrogen can effectively prevent bone loss induced by D-galac-tose and OVX+ D-galactose.

Piper sarmentosum Improves Bone Structure and Biomechanical Strength of Rats Given Excess Glucocorticoid.

Aims: To determine the effect of Piper sarmentosum (Ps) leaf extract on biomechanical strength and trabecular structure of the bones of glucocorticoid-induced osteoporotic rats. Study Design: Administration of crude extract to rats with excessive glucocorticoids. Place and Duration of Study: Department of Anatomy and Pharmacology, National University of Malaysia, between September 2010 and December 2011. Methodology: Three-month old male Sprague-Dawley rats were adrenalectomized to remove the main source of circulating glucocorticoids. The animals were replaced with dexamethasone 120 μg/kg body weight/day. Treatment with P. sarmentosum 125 mg/kg body weight and glycirrhizic acid (GCA) 120 mg/kg body weight were given simultaneously for 2 months. After been sacrificed, a three-point bending configuration test for assessing the biomechanical properties of the right femoral bones was done using an Instron Universal testing machine equipped with Instron Bluehill software. The left undecalcified femoral bones were embedded in resin, sectioned and stained with Von Kossa for structural histomorphometric measurements. Results: P. sarmentosum extract had significantly increased the intrinsic parameter (flexure modulus) and extrinsic parameter (energy at break) of the biomechanical properties of the bone. It had also significantly improved the trabecular structure by increasing the BV/TV, Tb.Th, Tb.N and by reducing the Tb.Sp based on histomorphometric analysis. Conclusion: P. sarmentosum extract was able to protect bone biomechanical strength in glucocorticoid-induced osteoporotic bone, as confirmed by the structural histomorphometric finding. Therefore, Ps extract has the potential to be used as an agent to protect the bone strength and structure against osteoporosis due to chronic glucocorticoid treatment. These results however, need further study for better justification.