scholarly journals Recovery Effects of a 180 mT Static Magnetic Field on Bone Mineral Density of Osteoporotic Lumbar Vertebrae in Ovariectomized Rats

2011 ◽  
Vol 2011 ◽  
pp. 1-8 ◽  
Author(s):  
Shenzhi Xu ◽  
Hideyuki Okano ◽  
Naohide Tomita ◽  
Yoshito Ikada
Keyword(s):  
Magnetic Field ◽  
Bone Mineral Density ◽  
Bone Mineral ◽  
Static Magnetic Field ◽  
Lumbar Vertebrae ◽  
Exposed Group ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Moderate Intensity ◽  
Mineral Density

The effects of a moderate-intensity static magnetic field (SMF) on osteoporosis of the lumbar vertebrae were studied in ovariectomized rats. A small disc magnet (maximum magnetic flux density 180 mT) was implanted to the right side of spinous process of the third lumbar vertebra. Female rats in the growth stage (10 weeks old) were randomly divided into 4 groups: (i) ovariectomized and implanted with a disc magnet (SMF); (ii) ovariectomized and implanted with a nonmagnetized disc (sham); (iii) ovariectomized alone (OVX) and (vi) intact, nonoperated cage control (CTL). The blood serum 17--estradiol (E2) concentrations were measured by radioimmunoassay, and the bone mineral density (BMD) values of the femurs and the lumbar vertebrae were assessed by dual energy X-ray absorptiometry. The E2concentrations were statistically significantly lower for all three operated groups than those of the CTL group at the 6th week. Although there was no statistical significant difference in the E2concentrations between the SMF-exposed and sham-exposed groups, the BMD values of the lumbar vertebrae proximal to the SMF-exposed area statistically significantly increased in the SMF-exposed group than in the sham-exposed group. These results suggest that the SMF increased the BMD values of osteoporotic lumbar vertebrae in the ovariectomized rats.

scholarly journals Short- and long-term effects of calcium and exercise on bone mineral density in ovariectomized rats

2001 ◽  
Vol 86 (4) ◽  
pp. 521-527 ◽  
Author(s):  
Joseé Gala ◽  
Manuel Di´az-curiel ◽  
Concepcioó de la Piedra ◽  
Jesu´s Calero
Keyword(s):  
Bone Mineral Density ◽  
Bone Loss ◽  
Bone Mineral ◽  
Exercise Programme ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Standard Diet ◽  
Mineral Density ◽  
Left Femur ◽  
Ovx Rats

At the level of prevention of bone mineral loss produced by ovariectomy, the aim of the present study was to determine the effect produced by supplementation of Ca in the diet and a moderate exercise programme (treadmill), simultaneously or separately, in ovariectomized rats, an experimental model of postmenopausal bone loss. Female Wistar rats (n110, 15 weeks old) were divided into five groups: (1) OVX, rats ovariectomized at 15 weeks of age, fed a standard diet; (2) SHAM, rats sham operated at 15 weeks of age, fed a standard diet; (3) OVX–EX, ovariectomized rats, fed a standard diet and performing the established exercise programme; (4) OVX–Ca, ovariectomized rats fed a diet supplemented with Ca; (5) OVX–EXCa, ovariectomized rats with the exercise programme and diet supplemented with Ca. The different treatments were initiated 1 week after ovariectomy and were continued for 13 weeks for subgroup 1 and 28 weeks for subgroup 2, to look at the interaction of age and time passed from ovariectomy on the treatments. Bone mineral density (BMD) was determined, at the end of the study, in the lumbar spine (L2, L3 and L4) and in the left femur using a densitometer. Bone turnover was also estimated at the end of the study, measuring the serum formation marker total alkaline phosphatase (AP) and the resorption marker serum tartrate-resistant acid phosphatase (TRAP). As expected, OVX rats showed a significant decrease (P<0·05) in BMD, more pronounced in subgroup 2, and a significant increase in AP and TRAP with regard to their respective SHAM group. The simultaneous treatment with Ca and exercise produced the best effects on lumbar and femoral BMD of ovariectomized rats, partially avoiding bone loss produced by ovariectomy, although it was not able to fully maintain BMD levels of intact animals. This combined treatment produced a significant increase in AP, both in subgroups 1 and 2, and a decrease in TRAP in subgroup 1, with regard to OVX group. The exercise treatment alone was able to produce an increase in BMD with regard to OVX group only in subgroup 1 of rats (younger animals and less time from ovariectomy), but not in subgroup 2. In agreement with this, there was an increase of AP in both subgroups, lower than that observed in animals submitted to exercise plus Ca supplement, and a decrease of TRAP in subgroup 1, without significant changes in this marker in the older rats. Ca treatment did not produce any significant effect on BMD in OVX rats in both subgroups of animals, showing a decrease of AP and TRAP levels in the younger animals with no significant variations in markers of bone remodelling in the older female rats compared with their respective OVX group.

scholarly journals Metabolomics and physiological analysis of the effect of calcium supplements on reducing bone loss in ovariectomized rats by increasing estradiol levels

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Hongmei Mao ◽  
Wenjun Wang ◽  
Lili Shi ◽  
Chen Chen ◽  
Chao Han ◽  
...  
Keyword(s):  
Bone Mineral Density ◽  
Bone Loss ◽  
Bone Mineral ◽  
Calcium Supplementation ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Type I ◽  
Serum Estradiol ◽  
Mineral Density ◽  
Estradiol Levels

Abstract Background Data from the 2010–2012 Chinese National Nutrition and Health Survey showed that the vast majority of postmenopausal women in China had dual deficiencies in calcium and estrogen. Objective This study aimed to clarify whether calcium supplementation alleviated bone loss caused by calcium restriction combined with estrogen deficiency in rats. Methods Forty-eight female rats aged 9 weeks were assigned to 4 groups and fed a low-calcium diet: sham-operated (SHAM-LC), ovariectomized (OVX-LC), and ovariectomized rats treated with 750 mg/kg (OVX-LC-M) or 2800 mg/kg CaCO3 (OVX-LC-H). CaCO3 or distilled water was administered orally for 13 weeks. Bone mineral density (BMD) and histomorphometry of the femur, serum biochemical parameters, and serum metabolites were analyzed. Results The OVX-LC rats showed a significant increase in body weight and serum levels of lipid markers, a significant decrease in serum estradiol, calcium, phosphorus, and 25(OH)D levels, and deterioration of the femur. At 750 mg/kg and 2800 mg/kg, CaCO3 reduced the deterioration of trabecular bone and increased the trabecular area percentage (Tb.Ar %) and BMD of the femur. Serum estradiol levels increased in a dose-dependent manner after CaCO3 supplementation (p < 0.01). The administration of 2800 mg/kg CaCO3 decreased serum triglyceride and high-density lipoprotein levels (p < 0.05) and decreased the levels of the bone turnover markers osteocalcin, N-telopeptide of type I collagen and β-crosslaps. The results of the metabolomics analysis showed that the glycerophospholipid metabolism pathway was closely related to calcium supplementation, and more DG (44:6 n3), LysoPC (22:2) and PE (P-34:3) and less Cer (d43:0) and PE-NMe2 (46:3) were produced. Conclusions The results clearly indicated that calcium supplementation was beneficial for decreasing bone loss in OVX-LC rats. The present study is the first to show that calcium supplementation increased the estradiol content in OVX-LC rats, and the effect of calcium on bone loss may be partially attributed to the increase in the estrogen level that subsequently induced the changes in metabolite levels, eventually increasing the bone mineral density to a relatively higher level to reduce bone deterioration.

scholarly journals Moderate intensity swimming training on bone mineral density preservation under food restriction in female rats

2020 ◽  
Vol 26 (4) ◽  
Author(s):  
Taciane Maria Melges Pejon ◽  
Claudio Alexandre Gobatto ◽  
Victor Fabrício ◽  
Wladimir Rafael Beck
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Food Restriction ◽  
Female Rats ◽  
Moderate Intensity ◽  
Swimming Training ◽  
Mineral Density

Impaired Estrogen Sensitivity in Bone by Inhibiting Both Estrogen Receptor a and b Pathways*

2020 ◽  
Author(s):  
Lungwani Muungo
Keyword(s):  
Bone Mineral Density ◽  
Estrogen Receptor ◽  
Bone Loss ◽  
Bone Turnover ◽  
Bone Mineral ◽  
Female Rats ◽  
Wild Type ◽  
Mineral Density ◽  
Transgenic Rats ◽  
Estrogen Sensitivity

Although it is well established that estrogen deficiencycauses osteoporosis among the postmenopausalwomen, the involvement of estrogen receptor (ER) in itspathogenesis still remains uncertain. In the presentstudy, we have generated rats harboring a dominantnegative ERa, which inhibits the actions of not only ERabut also recently identified ERb. Contrary to our expectation,the bone mineral density (BMD) of the resultingtransgenic female rats was maintained at the same levelwith that of the wild-type littermates when sham-operated.In addition, ovariectomy-induced bone loss wasobserved almost equally in both groups. Strikingly, however,the BMD of the transgenic female rats, after ovariectomized,remained decreased even if 17b-estradiol(E2) was administrated, whereas, in contrast, the decreaseof littermate BMD was completely prevented byE2. Moreover, bone histomorphometrical analysis ofovariectomized transgenic rats revealed that the higherrates of bone turnover still remained after treatmentwith E2. These results demonstrate that the preventionfrom the ovariectomy-induced bone loss by estrogen ismediated by ER pathways and that the maintenanceof BMD before ovariectomy might be compensatedby other mechanisms distinct from ERa and ERbpathways.

The effect of prolactin itself and in combination with estrogen on bone mineral density in female rats

2019 ◽  
Vol 35 (6) ◽  
pp. 539-543 ◽  
Author(s):  
Forough Saki ◽  
Faezeh Sadeghian ◽  
Seyed Reza Kasaee ◽  
Pedram Talezadeh ◽  
Gholam Hossein Ranjbar Omrani
Keyword(s):  
Bone Mineral Density ◽  
Bone Mineral ◽  
Female Rats ◽  
Mineral Density

scholarly journals Jumping exercise preserves bone mineral density and mechanical properties in osteopenic ovariectomized rats even following established osteopenia

2017 ◽  
Vol 28 (4) ◽  
pp. 1461-1471 ◽  
Author(s):  
R . Okubo ◽  
L. S. Sanada ◽  
V. A. Castania ◽  
M. J. Q. Louzada ◽  
F. J. A. de Paula ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Mineral Density ◽  
Bone Mineral ◽  
Ovariectomized Rats ◽  
Mineral Density ◽  
Jumping Exercise
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