Bone Mineral Density In Ovariectomized Rats Research Articles

Cytokines CCL2 and CXCL1 may be potential novel predictors of early bone loss.

Osteoporosis is a common disorder characterized by decreased bone mineral density (BMD) and increased fracture risk. The current techniques detect real-time BMD precisely but do not provide adequate information to predict early bone loss. If bone loss could be diagnosed and predicted early, severe osteoporosis and unexpected fractures could be prevented, allowing for an improved quality of life for individuals. In the present study, an ovariectomized rat model of bone loss was established and the serum levels of 78 potential cytokines were determined using a protein array. The BMD of ovariectomized rats was dynamically measured by micro-CT and the early stage of bone loss was defined at the fourth week after surgery. The expression of several serum protein cytokines was indicated to be altered in the ovariectomized rats during an 8-week time-course of bone loss. Linear regression analysis revealed that the serum levels of C-C motif chemokine ligand 2 (CCL2, also known as monocyte chemoattractant protein 1) and C-X-C motif chemokine ligand 1 (CXCL1) were significantly associated with a reduction in BMD. The significance of these two factors in indicating bone mass reduction was further verified by analyzing serum samples from 24 patients with BMD using ELISA and performing a linear regression analysis. The serum levels of CCL2 and CXCL1 were inversely correlated with the bone mass. Therefore, the cytokines CCL2 and CXCL1 may be potential novel predictors of early bone loss and may be clinically relevant for the early diagnosis and prevention of osteoporosis.

Comparison of the Effects of Deer Antler, Old Antler, and Antler Glue on Osteoporosis in Ovariectomized Rats

Background: Examination of the effects of deer antler, old antler, and antler glue on postmenopausal osteoporosis in an ovariectomized Sprague-Dawley rat model. Methods: The study involved 7 experimental groups; SHAM (sham-operated rats), OVX (ovariectomized rats), E2 (ovariectomized rats with estradiol 10 μg/kg daily, orally), DA (ovariectomized rats with deer antler extract 5.83 mg/kg), OA (ovariectomized rats with old antler extract 3.8 mg/kg), low-AG (ovariectomized rats with low dose of antler glue powder 12.5 mg/kg), high-AG (ovariectomized rats with high dose of antler glue powder 37.5 mg/kg). After 6 weeks of treatment, body weight, blood calcium, phosphorus, estradiol, liver [alkaline phosphatase (ALP), aspartate transaminase (AST), alanine transaminase (ALT)] and kidney [blood urea nitrogen (BUN)/creatinine ratio] function, and femoral bone mineral density (BMD) were measured. Results: The body weights of DA, OA, low-AG, and high-AG groups did not significantly differ from OVX group. Blood estradiol levels were significantly increased in the DA, low-AG, and high-AG groups compared to the OVX group. Blood calcium, phosphorus, ALP, AST, and ALT levels and BUN/creatinine ratio did not show significant changes in the DA, OA, low-AG, and high-AG groups. BMDs of the femur, and femoral head and neck were significantly increased in the low-AG group. In the OA group, the BMD of the femoral head and neck was significantly increased. Conclusion: Treatment with deer antler, or antler glue for 6 weeks was effective for increasing estradiol and femoral BMD in ovariectomized rats, suggesting that this may be of therapeutic benefit for osteoporosis. ⓒ2018 Korean Acupuncture & Moxibustion Medicine Society. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).

Effect of Er-xian decoction on femur proteomics in ovariectomized osteoporosis rats

This experiment was mainly aimed to investigate the effect of Er-xian decoction on osteoporosis and the femur proteomics in ovariectomized rats with osteoporosis. The female SD rats were randomly divided into sham operation group, model group, Alendronate group (1 mg•kg⁻¹), Er-xian decoction group (in dose of 8 g•kg⁻¹) according to their weight. The rats in sham operation group and model group were gavaged with normal saline; the rats in Alendronate group were gavaged with the Alendronate at the dose of 1 mg•kg⁻¹ and the rats in Er-xian decoction group were gavaged with Er-xian decoction at the dose of 8 g•kg⁻¹, once a day for continuous 90 days. Then the femoral bone mineral density (BMD) was detected. The femoral bone proteins were detected by NanoLC-LTQ-Orbitrap system, identified by Protein Discovery software, and the intensity of differentially expressed proteins were quantitated by SIEVE software. The results showed that Er-xian decoction could significantly improve femoral BMD in ovariectomized rats. As compared with model group, 41 differentially expressed proteins whose variation trend was consistent with the sham operation group, were found in Er-xian decoction group, mainly including biological oxidation related protein, signal transduction pathway related protein, proteins involved in aliphatic acid metabolism, cytoskeleton related protein, proteins involved in energy metabolism, and proteins involved in glucose metabolism etc. The osteoporosis could be prevented and cured by Er-xian decoction. The differentially expressed proteins such as carbonic anhydrase 2 and integrin β1 may be the action targets for Er-xian decoction.

Perioperative alendronate, risedronate, calcitonin and indomethacin treatment alters femoral stem fixation and periprosthetic bone mineral density in ovariectomized rats

BackgroundMany factors affect implant stability and periprosthetic bone mineral density (BMD) following total joint arthroplasty. We asked whether perioperative alendronate, risedronate, calcitonin and indomethacine administration altered (1) femoral stem shear strength and periprosthetic bone mineral density BMD in ovariectomized rats and (2) whether there were differences in the effect of these drugs. MethodsThirty overiectomized rats were divided into five groups and implanted with intramedullary mini-cortical screws in the femur. Four groups were treated with alendronate, risedronate, salmon calcitonin and indomethacin for 4 weeks preoperatively and 8 weeks postoperatively. ResultsAlthough alendronate and risedronate increased the periprosthetic BMD more than calcitonin, they did not alter implant fixation compared to calcitonin. Indomethacin significantly decreased the BMD around the stem and implant stability compared to all other groups. ConclusionsThis study showed that perioperative treatment with bisphosphonates and calcitonin improved the BMD around the stems and implant stability. Although bisphosphonates increased the BMD more than calcitonin, there was no difference in implant stability. Indomethacin markedly decreased the periprosthetic BMD and implant stability. The main clinical significance of our study was the finding about the need to strictly avoid long-term use of high-dose nonsteroidal antiinflammatory drugs for patients who have major joint arthritis and a previous history of arthroplasty.

Hepatic magnetic resonance imaging with T2* mapping of ovariectomized rats: correlation between iron overload and postmenopausal osteoporosis.

To explore the correlation between liver iron overload and bone mineral density (BMD) in an ovariectomy (OVX) rat model, using liver magnetic resonance (MR)-T2* and dual-energy X-ray absorptiometry (DEXA). Sprague-Dawley rats received deferoxamine (DFO) or phosphate-buffered saline 3 months after bilateral OVX. MRI and DEXA were performed pre- and postoperatively. Five rats per group were killed every month for micro-CT, histopathology and biochemical examinations. Statistical analysis was performed with independent-samples t tests, box plots and Pearson's correlation analysis. At 2 months postoperatively, BMD was significantly lower in the OVX group than in the control group (P < 0.01), corresponding to the increased serum ferritin concentration (SFC; P < 0.01) and liver iron concentration (LIC; P < 0.01). Liver T2* values significantly differed between the two groups at 1 month postoperatively (P < 0.001) and improved 1 month after DFO injection (P < 0.05). These values were significantly and positively correlated with BMD in the control (r = 0.527, P < 0.001) and OVX (r = 0.456, P < 0.001) groups. Liver MRI T2* changed markedly earlier than BMD, LIC and SFC, and correlated well with osteoporosis; it may thus be a valuable early indicator of osteoporosis. • Iron overload plays a vital role in the pathogenesis of postmenopausal osteoporosis. • Liver T2* relaxation time is a sensitive value in reflecting iron overload. • Liver T2* mapping elucidates changes in postmenopausal osteoporosis earlier than BMD. • Iron chelation increases BMD in ovariectomized rats. • Liver T2* has a moderate positive correlation with BMD.

Effect of whole body vibration therapy on circulating serotonin levels in an ovariectomized rat model of osteoporosis.

Studies have reported that whole body vibration (WBV) played a vital role in bone remodeling. Circulating serotonin is also involved in negative regulating bone mass in rodents and humans. However, both WBV and inhibition of serotonin biosynthesis may suppress receptor activator of nuclear factor-kappaB ligand (RANKL)-induced osteoclastogenesis in vitro. The purpose of the current study was to investigate the effect of WBV therapy on the levels of serum serotonin in ovariectomized rats. Thirty-six-month-old female Sprague Dawley rats weighing 276.15±37.75 g were ovariectomized to induce osteoporosis, and another ten rats underwent sham operation to establish sham control (SHAM) group. After 3 months, ovariectomized rats were divided into three subgroups and then separately treated with WBV, Alendronate (ALN) and normal saline (OVX), SHAM group was given normal saline. After 6 weeks of treatment, rats were sacrificed. Serum serotonin, RANKL, bone turnover markers, and bone mineral density (BMD), bone strength were evaluated. The serum serotonin level was significantly lower in WBV group than OVX and ALN groups (P<0.05 and P<0.001). RANKL levels significantly decreased in WBV and ALN groups compared to OVX group (P<0.001 for both). BMD and biomechanical parameters of femur significantly increased (P<0.05 for both) and bone turnover levels decreased (P<0.001 for both) in WBV group compared to OVX group. These data indicated that WBV enhanced the bone strength and BMD in ovariectomized rats most likely by reducing the levels of circulating serotonin.

Effects of strontium ranelate, raloxifene and misoprostol on bone mineral density in ovariectomized rats

Objectives To investigate the effects of strontium ranelate, raloxifene and misoprostol on bone mineral density (BMD) in ovariectomized rats to contribute to the individualization of the treatment of postmenopausal osteoporosis. Study design Sixty sexually mature female Sprague–Dawley rats weighing 250 g were used. The 60 rats were divided into six groups of 10 rats each: SR, MISO, RAL, SHAM, DW and OVX. All except the SHAM rats were subjected to bilateral ovariectomy. Three days after surgery, rats were administered strontium ranelate (Protelos ®, 2 g, Servier, Istanbul), 1800 mg/kg/day; misoprostol (Cytotec ®, 200 mcg, Ali Raif, Istanbul), 200 mcg/kg/day; raloxifene (Evista ®, 60 mg, Lily and Company, Istanbul), 3 mg/kg/day and 1 cc of distilled water by gavage for 8 weeks. Bone mineral density measurements were then performed. Results The strontium ranelate (SR) group had significantly higher vertebral BMD than all other groups. Femoral density in the SR group was also significantly higher than in other groups and there was no difference between femoral density in the strontium ranelate and sham groups. Conclusions Strontium ranelate, raloxifene and misoprostol can prevent bone loss in the vertebrae, whereas strontium ranelate can also prevent bone loss in the femur of ovariectomized rats. Strontium ranelate increases greater than raloxifene and misoprostol BMD in the vertebrae. Condensation Strontium ranelate may increase both vertebral and femur BMD in ovariectomized rats while raloxifene and misoprostol may only increase lumbar spine BMD.

Evaluation of anti-osteoporosis in ovariectomized Wistar rats treated with antler blood by synchrotron radiation X-ray fluorescence microprobe

To evaluate the anti-osteoporotic effect of antler blood, the relationship between the change of element content and the bone mineral density (BMD) increase in femur was investigated. Female Wistar rats were randomly divided into three groups: sham-operated group (SHAM,n=5), ovariectomized group (OVX,n=5) and ovariectomized group with antler blood treatment (n=5). The femoral BMD was analyzed by dual-energy X-ray absorptiometry (DXA) and the element relative content was determined by synchrotron radiation X-ray fluorescence (SRXRF) microprobe. The results showed that the femoral BMD in ovariectomized rats was significantly lower than that of sham-operated rats (p&lt;0.05) but reversed by antler blood treatment (p&lt;0.05). A further study demonstrated that the relative contents of phosphorus (P), calcium (Ca), zinc (Zn) and strontium (Sr) were obviously lower in ovariectomized rats compared to sham-operated rats but only the relative contents of P, Ca and Zn were normalized by antler blood treatment (p&lt;0.05). Our experiments revealed that loss of element Ca, P, Zn and Sr was closely related to the BMD reduction in ovariectomized rats and the anti-osteoporotic effect of antler blood was mediated by increasing the contents of P, Ca and Zn.

Evaluation of anti-osteoporosis in ovariectomized Wistar rats treated with antler blood by synchrotron radiation X-ray fluorescence microprobe

To evaluate the anti-osteoporotic effect of antler blood, the relationship between the change of element content and the bone mineral density (BMD) increase in femur was investigated. Female Wistar rats were randomly divided into three groups: sham-operated group (SHAM, n = 5), ovariectomized group (OVX, n = 5) and ovariectomized group with antler blood treatment (n = 5). The femoral BMD was analyzed by dual-energy X-ray absorptiometry (DXA) and the element relative content was determined by synchrotron radiation X-ray fluorescence (SRXRF) microprobe. The results showed that the femoral BMD in ovariectomized rats was significantly lower than that of sham-operated rats (p < 0.05) but reversed by antler blood treatment (p < 0.05). A further study demonstrated that the relative contents of phosphorus (P), calcium (Ca), zinc (Zn) and strontium (Sr) were obviously lower in ovariectomized rats compared to sham-operated rats but only the relative contents of P, Ca and Zn were normalized by antler blood treatment (p < 0.05). Our experiments revealed that loss of element Ca, P, Zn and Sr was closely related to the BMD reduction in ovariectomized rats and the anti-osteoporotic effect of antler blood was mediated by increasing the contents of P, Ca and Zn.

Antiosteoporotic chemical constituents from Er-Xian Decoction, a traditional Chinese herbal formula

Aim of the study Er Xian Decoction (EXD), a traditional Chinese medicine formula, has long been used for the treatment of osteoporosis and menopausal syndrome in China. The present study was designed to investigate the antiosteoporotic constituents of EXD, and evaluate their antiosteoporotic effects in ovariectomized rats. Materials and methods Osteoblasts in neonatal calvaria cultures and osteoclasts derived from rat marrow cells were used to bioactivity-guided screen the active constituents. The proliferation of osteoblast was assayed by MTT methods. The activity of ALP and TRAP was measured by p- nitrophenyl sodium phosphate assay. The antiosteoporotic effects of icariin (1), anemarsaponin B II (8) and berberine (6) were verified by using OVX rats model. The bone mineral density (BMD) was measured by dual-energy X-ray absorptiometry using the small animal scan mode. The undecalcified longitudinal proximal tibial metaphysical (PTM) sections were cut and stained for the bone histomorphometric analysis. Results Bioactivity-guided fractionation has led to the successful isolation of antiosteoporotic constituents, i.e., icariin (1), icariside I (2), baohuoside I (3), mangiferin (4), neomangiferin (5), berberine (6), anemarsaponin B (7), anemarsaponin BII (8), anemarsaponin C (9), anemarrhenasaponin I (10), rubiadin-1-methyl ether (11) and obaculactone (12) from EXD. Further study showed that icariin (1), anemarsaponin BII (8) and berberine (6) increased the BMD in ovariectomized rats, and icariin (1) not only increased the bone formation, but also inhibited bone resorption; anemarsaponin BII (8) mainly increased bone formation and berberine (6) only inhibited the bone resorption in ovariectomized rats. Conclusion Our findings demonstrate that multiple ingredients are responsible for antiosteoporotic activity in traditional Chinese medicine formula Er-Xian decoction.

Treatment of osteoporosis with TheraCyte-encapsulated parathyroid cells: a study in a rat model

The purpose of this study was to evaluate parathyroid function at monthly intervals following the implantation of TheraCyte-encapsulated live human parathyroid cells into ovariectomized rats and to determine the effect on bone mineral density (BMD) 4 months after ovariectomy ( 3 months after implantation). Parathyroid tissues were obtained from patients undergoing surgery for secondary hyperparathyroidism. In total, 21 Sprague-Dawley rats divided randomly into three groups were subjected to one of three treatments: (1) implanted with TheraCyte A-encapsulated 4x10(6) live parathyroid cells; (2) implanted with TheraCyte B-encapsulated 4x10(5) live parathyroid cells; (3) a sham operation; the control group. Rats were ovariectomized 1 month prior to the implantation of the TheraCyte. Blood was drawn at the time of implantation and at monthly intervals thereafter for 3 months to check the levels of calcium, phosphorus and intact parathyroid hormone (iPTH). The BMD of the lumbar spine (L1-L5) and of the left femoral bone was measured with dual-energy-X-ray absorptiometry (DEXA) 1 month after ovariectomy and 3 months after implantation of the TheraCyte (4 months after ovariectomy). We found that the viability ratio of cryopreserved tissues was between 55 and 79% after thawing. In the control group, the BMD of the lumbar spine (L1-L5) had not decreased significantly (p=0.237) nor had the BMD of the left femoral bone increased significantly (p=0.063) 3 months after implantation. In the TheraCyte A group, the BMD of both the lumbar spine (p=0.018) and left femoral bone (p=0.018) had increased significantly 3 months after implantation. In the TheraCyte B group, the BMD of both the lumbar spine (p=0.017) and the left femoral bone (p=0.025) had also increased significantly 3 months after implantation. Serum iPTH levels were higher in the TheraCyte A group than in the TheraCyte B group (p=0.006), and higher in the TheraCyte B group than in the control group (p=0.040). Serum calcium levels were not significantly higher in the TheraCyte group A than in the TheraCyte B group or in the control group. Serum phosphorus levels were not significantly different between the TheraCyte A and TheraCyte B groups. Implantation of TheraCyte A-encapsulated 4x10(5) live parathyroid cells and TheraCyte B-encapsulated 4x10(6) cells can increase the BMD of ovariectomized rats within 3 months of implantation. Neither cause high serum calcium and low phosphorus concentrations.

Treatment with vitamin D3 and/or vitamin K2 for postmenopausal osteoporosis.

It is established in Japan that treatment with 1alpha-hydroxyvitamin D3 (alfacalcidol) slightly reduces bone turnover, sustains lumbar bone mineral density (BMD), and prevents osteoporotic vertebral fractures in postmenopausal women with osteoporosis, while vitamin K2 (menatetrenone) enhances gamma-carboxylation of bone glutamic acid residues and secretion of osteocalcin, sustains lumbar BMD, and prevents osteoporotic fractures in patients with osteoporosis. Available evidence suggests that the effect of vitamin K2 on mineralization by human periosteal osteoblasts is enhanced in the presence of 1,25 dihydroxyvitamin D3 in vitro. The effect of vitamin K2 on BMD in ovariectomized rats is affected by the plasma 25-hydroxyvitamin D3 level in vivo, and is significant only when rats are fed a diet containing vitamin D3. Based on this line of evidence, combined treatment with alfacalcidol and menatetrenone for osteoporosis is surmised to be more effective than treatment with menatetrenone alone, and may have anabolic effects on osteoporotic bone. This combined treatment may increase bone formation as well as bone resorption over the mild anti-resorptive effect of alfacalcidol itself, and shows the greatest effect on lumbar BMD or the incidence of vertebral fractures in studies in which the mean age and years since menopause of subjects were low and the degree of osteoporosis was mild. It may be effective for mild postmenopausal osteoporosis in which age-related deterioration of trabecular bone properties remains below the threshold for vertebral fractures, even if bone resorption is increased and trabecular bone has deteriorated.

Frequency-dependent effect of nitric oxide donor nitroglycerin on bone.

Recently, we showed that supplementation with nitric oxide (NO) via donor nitroglycerin (NG) alleviated the ovariectomy and corticosteroid-induced bone loss in rats. In humans, high doses or frequent applications of NG (i.e., for angina) lead to rapid loss of its efficacy in relieving angina. To examine whether there is a similar effect on the loss of efficacy of NG on bone, we examined the frequency-dependent effects of NG on bone mineral density (BMD), bone mass, trabecular bone volumes (BV/TV), and blood pressure in rats. Thirty 7-month-old female Brown Norway rats underwent ovariectomy, and an additional six rats were sham-operated. The ovariectomized rats were treated either with vehicle (ovariectomized control), 17beta-estradiol (E2; positive control), or 0.2 mg NG (via dermal application) once, twice, or three times a day. Before and at the end of the 10-week treatment period, BMD of the lumbar spine was measured by dual-energy X-ray absorptiometric (DXA) scanning and expressed as a percentage change. BMD in ovariectomized rats was significantly lower (-2.5 +/- 2.0%) compared with the sham-operated rats (+6.3 +/- 5.3%; p < 0.01). Estrogen therapy completely abolished the ovariectomy-induced potential bone loss (+5.9 +/- 3.4%). Application of NG once daily also completely prevented (+6.2 +/- 2.8%; p < 0.01) the ovariectomy-induced bone loss (i.e., it was as effective as estrogen). However, the beneficial effects of NG on BMD were significantly reduced with increased frequency of application of NG (+1.9 +/- 2.1%, twice a day and -0.2 +/- 3.3% three times a day). Estrogen or once daily administration of NG preserved femur weights, BV/TV, and decreased urinary deoxypyridinoline levels as expected. However, a higher level of serum osteocalcin and bone-specific alkaline phosphatase levels were maintained only with once daily administration of NG. There were no adverse effects of these doses of NG on blood pressure, but a tendency to lower blood pressure was noticed with increased frequency of NG. These results confirmed our previous findings that NO donors counteract the bone loss associated with estrogen deficiency. However, these beneficial effects of maintaining BMD are lost with increased frequency of NG application.

Effect of ovariectomy and calcium deficiency on the ultrasound velocity, mineral density and strength in the rat femur

Objective. Ultrasound transmission velocity (UTV) and bone mineral density (BMD) were examined as possible predictors of the bending strength of osteoporotic long bones in ovariectomized rats treated with calcium-depleted diet. Background. Changes in cancellous bone quality due to osteoporosis have been well documented, but only a few studies described non-invasive assessment of the biomechanical quality of long bones. Methods. Forty-three rats were divided into three groups: ovariectomized and calcium-depleted diet, ovariectomized and standard diet, and untreated controls. All femora were scanned by quantitative computed tomography (QCT) to measure BMD and cortical dimensions at the mid-diaphysis. Bending strength was determined from the maximum bending moment and the femoral cortical dimensions at the mid-diaphysis. The UTV of cortical bond at the mid-disphysis of the femur was measured in the proximal/distal direction. Results. It was found that bending strength was significantly different among the groups ( p < 0.0001). Despite the fact that bending strength of the osteoporotic rat femur significantly decreased, the osteoporotic effect did not produce a significant change in cortical thickness. UTV in the ovariectomized and calcium-depleted diet was lower than in the other groups; however, no significant differences were found betwene those on the standard diet and the untreated controls. The BMD in ovariectomized rats was also significantly lower than in the untreated controls ( p < 0.05); however, the BMD in those fed with the calcium-depleted diet was not significantly different from those with the standard diet. Both cortical UTV and BMD as a single variable may not predict changes in bending strength of the cortical bone at the mid-diaphysis of the rat femur. However, the combined effect of UTV and BMD was significantly better than a single parameter in the assessment of strength.