Bone Mineral Density Mineral Content Research Articles

Untargeted metabolomics reveals the effect of rearing systems on bone quality parameters in chickens.

The objective of this study was to investigate the effects of rearing systems on the bone quality parameters in chickens using a metabolomics strategy. A total of 419 male one-day-old chicks were randomly allocated to two groups, a floor rearing group (FRG, n = 173) and a cage rearing group (CRG, n = 246). At 6, 8, 10, and 12weeks of age, all chickens were radiographed by a digital X-ray machine, and body weight was recorded. At 12weeks of age, 12 birds were selected from each group to obtain tibia and femur, and bone quality parameters of bone mineral density (BMD), mineral content (BMC), breaking strength (BBS), stiffness, Young's modulus (YM), ash content, calcium content, and phosphorus content were determined. An untargeted metabolomics assay was performed to identify changes in the serum metabolic profile (n = 8 birds/group). The results showed that cage-reared chickens had wider tibiae and greater body weight compared with floor-reared chickens. There were no significant differences in BMC or BBS between the two groups (p > 0.05), but BMD, ash content, calcium content, and phosphorus content of the tibia and femur of FRG were significantly higher than those of CRG (p < 0.05). Greater stiffness and YM of the femur were also observed in birds raised in the FRG compared with those raised in the CRG (p < 0.05). Taken together, the results suggest that rearing systems affected bone quality parameters. Furthermore, 148 and 149 differential metabolites were identified in positive and negative ion modes by LC-MS/MS analysis, among which 257 metabolites were significantly correlated with 16 bone quality parameters, including leucine, myristoleic acid, glycocholic acid, and N-phenylacetamide. KEGG analysis indicated that 15 metabolic pathways, including six pathways of amino acid metabolism, two pathways of lipid metabolism, and two pathways of carbohydrate metabolism, were responsible for bone quality. Overall, the present study demonstrated the effect of rearing systems on bone quality parameters, and identified several metabolites and metabolic pathways associated with bone quality parameters.

Taro (Colocasia esculenta) flour intake enable bone integrity in male rats

Objetivo: A proposta deste estudo foi investigar a composição óssea em ratos tratados com dieta suplementada com farinha de taro (Colocasia esculenta) até eles completarem 90 dias de idade. Métodos: No momento do desmame, os ratos foram divididos em grupo controle (C, n = 11) e experimental (T, n = 12) – composto por animais tratados com farinha de taro até os 90 dias de idade. Ingestão alimentar, massa e comprimento corporal foram avaliados semanalmente ao longo de todo o período experimental. Dimensões ósseas, bem como a densidade mineral óssea (DMO), conteúdo mineral ósseo (CMO), área óssea total e propriedades biomecânicas foram determinadas no final de 90 dias. Resultados: Grupo T apresentou elevados valores (P&lt;0.05) para massa e comprimento corporal; DMO, CMO e área óssea da coluna vertebral; DMO na quarta vértebra lombar; massa femoral, distância entre as epífises, largura do ponto médio da diáfise, DMO, força máxima e concentrações séricas de osteocalcina, quando comparado ao grupo controle. Conclusões: A ingestão da farinha de taro apresentou efeito positivo na saúde óssea.

The effect of topiramate and lamotrigine on rat bone mass, structure and metabolism

There is only limited data concerning the effect of the newer antiepileptic drugs on bone. The objective of this study was to determine the effect of topiramate (TPM) and lamotrigine (LTG) monotherapy on bone mineral density (BMD), mineral content (BMC), bone markers, body composition and bone mechanical strength in the orchidectomized (ORX) rat model.24 orchidectomized Wistar rats were divided into control and test groups, 8 rats in each group. The control rats received standard laboratory diet (SLD) while rats in the test group were fed with SLD enriched with LTG or TPM for 12weeks. Dual energy X-ray absorptiometry was used to measure bone mineral density. The concentrations of bone metabolism markers were assayed in bone homogenate. In addition, both femurs were measured and used for biomechanical testing.Compared to the control group, both test groups had significantly lower weight, fat mass, whole body and femur BMD, BMC and reduced mechanical strength of bone. All of these changes were more pronounced in rats exposed to LTG.In conclusion, both LTG and TPM significantly reduce BMD and body weight and impair mechanical strength of bone. A question arises as to the degree of dependence of the effect on the dose. Further studies are warranted to establish whether LTG and TPM may have a clinically significant effect on BMD exclusively in the model of gonadectomized rats, or whether the effect applies also in the model of gonadally intact animals, and in the respective human models.

The effect of levetiracetam on rat bone mass, structure and metabolism

To determine the effect of levetiracetam (LEV) Lon bone mineral density (BMD), mineral content (BMC), bone markers, body composition and bone mechanical strength in the orchidectomised (ORX) rat model. 16 orchidectomised Wistar rats were divided into control and test groups, 8 rats in each group. The control rats received standard laboratory diet (SLD) while rats in the test group were fed with SLD enriched with LEV for 12 weeks. BMD was measured by dual energy X-ray absorptiometry at the whole body, lumbar spine and femur. Bone marker concentrations were examined of osteoprotegerin (OPG) and insulin-like growth factor 1 (IGF-1) in serum, and amino-terminal propeptide of procollagen type I (PINP), carboxy-terminal cross-linking telopeptide of type I collagen (CTX-I), bone alkaline phosphatase (ALPL), and bone morphogenetic protein 2 (BMP-2) in bone homogenate. The femurs were used for biomechanical testing. Compared to the control group we found lower fat mass, lower BMD in the area of the left femur, lower BMC in both femurs, a reduced concentration of OPG, and an increased concentration of CTX-I of borderline statistical significance (p=0.0661). Biomechanical parameters did not differ between groups. Significant loss of BMD or BMC was seen at the left and right femur area in the LEV group. Administration of LEV in the ORX-rat model significantly decreased levels of OPG (marker of bone formation) in serum and increased levels of CTX-I (marker of bone resorption) in bone homogenate, but results in this study did not reveal any change in biomechanical bone strength. Administration of LEV in the ORX-rat model may reduce adipose tissue. Further studies in animals and humans will be needed to confirm these findings.

Different Molecular Mechanisms Underlie Ethanol-Induced Bone Loss in Cycling and Pregnant Rats

Chronic ethanol (EtOH) consumption can result in osteopenia. In the current study, we examined the modulation of EtOH-induced bone loss during pregnancy. Nonpregnant and pregnant dams were intragastrically infused either control or EtOH-containing diets throughout gestation (gestation d 5 through 20 or an equivalent period of 15 d) by total enteral nutrition. The effects of EtOH (8.5 to 14 g/kg/d) on tibial bone mineral density (BMD), mineral content (BMC), and bone mineral area were assessed at gestation d 20 via peripheral quantitative computerized tomography. EtOH caused a dose-dependent decrease in BMD and BMC without affecting bone mineral area. Trabecular BMD and BMC were significantly lower in EtOH-treated, nonpregnant dams, compared with pregnant cohorts at the same infused dose of EtOH and urinary ethanol concentrations. Static histomorphometric analysis of tibiae from pregnant rats after EtOH treatment showed decreased osteoblast and osteoid surface, indicating inhibited bone formation, whereas EtOH-treated cycling rats showed higher osteoclast and eroded surface, indicative of increased bone resorption. Circulating osteocalcin and 1,25-dihydroxyvitamin D3 were lower in both EtOH-fed nonpregnant and pregnant rats. Gene expression of osteoclast markers, 70 kDa v-ATPase, and tartrate-resistant acid phosphatase were increased selectively in nonpregnant EtOH-treated rats but not pregnant rats. Moreover, only nonpregnant EtOH-fed rats showed induction in bone marrow receptor activator of nuclear factor-kappaB ligand mRNA and decreased circulating 17beta-estradiol levels. Our data suggest that EtOH-induced bone loss in pregnant rats is mainly due to inhibited bone formation, whereas in nonpregnant rats, the data are consistent with increased osteoclast activation and bone resorption concomitant with decreased estradiol levels.

Effect of melatonin on bone metabolism in ovariectomized rats

To assess the effect of pharmacological dose of melatonin on bone metabolism in ovariectomized rats, urinary deoxypyridinoline (a marker of bone resorption) and calcium excretion, circulating levels of calcium, phosphorus and bone alkaline phosphatase activity (a marker of bone formation), and bone mineral density (BMD), mineral content (BMC) and bone area (BA) of total body, were measured in adult rats for up to 60 days after surgery. Rats received melatonin in the drinking water (25 μg/ml water) or drinking water alone. Urinary deoxypyridinoline increased significantly after ovariectomy by 51% (30 days after surgery) and by 47% (60 days after surgery). The increase in urinary deoxypyridinoline found 30 days after ovariectomy was not observed in melatonin-treated rats. Urinary calcium concentration was similar in the 4 experimental groups studied, as was the circulating calcium concentration at every time interval examined. Fifteen days after surgery, a significant increase in serum phosphorus and bone alkaline phosphatase levels occurred in ovariectomized rats receiving melatonin as compared to their controls. Sixty days after surgery BMD, BMC and BA decreased significantly in ovariectomized rats, an effect not modified by melatonin. Serum estradiol decreased significantly by 30 days after ovariectomy to attain values close to the limit of detection of the assay by 60 days after ovariectomy. The results support the conclusion that a pharmacological amount of melatonin modifies bone remodeling after ovariectomy and that the effect may need adequate concentrations of estradiol.