1α-Hydroxyvitamin D2 Partially Dissociates Between Preservation of Cancellous Bone Mass and Effects on Calcium Homeostasis in Ovariectomized Rats

1997 ◽  
Vol 60 (5) ◽  
pp. 449-456 ◽  
Author(s):  
R. G. Erben ◽  
U. Bante ◽  
H. Birner ◽  
M. Stangassinger
Keyword(s):  
Bone Mass ◽  
Cancellous Bone ◽  
Calcium Homeostasis ◽  
Ovariectomized Rats

scholarly journals Sequential Treatment with Basic Fibroblast Growth Factor and PTH Is More Efficacious than Treatment with PTH Alone for Increasing Vertebral Bone Mass and Strength in Osteopenic Ovariectomized Rats

Endocrinology ◽  
2002 ◽  
Vol 143 (7) ◽  
pp. 2515-2526 ◽  
Author(s):  
U. T. Iwaniec ◽  
Li. Mosekilde ◽  
N. G. Mitova-Caneva ◽  
J. S. Thomsen ◽  
T. J. Wronski
Keyword(s):  
Bone Mass ◽  
Cancellous Bone ◽  
Sequential Treatment ◽  
Ovariectomized Rats ◽  
Concurrent Administration ◽  
Trabecular Microarchitecture ◽  
Trabecular Thickness ◽  
Vertebral Bone ◽  
Ovx Rats ◽  
Vertebral Bone Mass

Abstract The study was designed 1) to determine whether treatment with basic fibroblast growth factor (bFGF) and PTH is more efficacious than treatment with PTH alone for increasing bone mass and strength and improving trabecular microarchitecture in osteopenic ovariectomized rats, and 2) to assess whether prior and concurrent administration of the antiresorptive agents estrogen and risedronate suppresses the bone anabolic response to treatment with bFGF alone and sequential treatment with bFGF and PTH. Three-month-old female Sprague Dawley rats were ovariectomized (OVX) or sham-operated (sham) and maintained untreated for 1 yr. Baseline sham and OVX rats were killed at this time (15 months of age). Groups of rats were injected sc with estrogen (10 μg/kg, 4 d/wk), risedronate (5 μg/kg, 2 d/wk), or vehicle. At the end of the second week of antiresorptive treatment, catheters were inserted into the jugular veins of all rats, and vehicle or bFGF at a dose of 250 μg/kg was injected daily for 14 d. Three groups of rats were killed at the end of bFGF treatment. The remaining rats were continued on their respective antiresorptive therapy and injected sc with vehicle or synthetic human PTH-(1–34) at a dose of 80 μg/kg, 5 d/wk, for 8 wk. Lumbar vertebrae were processed for cancellous bone histomorphometry and biomechanical testing. Ovariectomy resulted in a decrease in vertebral bone mass and strength. Treatment of OVX rats for 14 d with bFGF markedly increased osteoblast surface, osteoid surface, and osteoid volume compared with vehicle treatment of sham and OVX rats. Furthermore, osteoid bridges were observed extending between preexisting trabeculae in bFGF-treated OVX rats. Prior and concurrent administration of estrogen and risedronate did not suppress these bone anabolic effects of bFGF. Treatment of OVX rats with PTH alone increased vertebral cancellous bone mass and strength to the level of vehicle-treated sham rats. Sequential treatment of OVX rats with bFGF and PTH further augmented vertebral bone mass and strength to a level above that observed in OVX rats treated with PTH alone. The improvements in bone mass and strength were associated with an increase in trabecular thickness in OVX rats treated with PTH alone and with an increase in trabecular thickness and node to terminus ratio, an index of trabecular connectivity, in OVX rats treated sequentially with bFGF and PTH. Cotreatment with estrogen and risedronate did not suppress the anabolic response of bone to bFGF and PTH. In fact, a trend for an even greater increase in cancellous bone mass and node to terminus ratio was observed in OVX rats treated with risedronate, bFGF, and PTH. These findings indicate that sequential treatment with bFGF and PTH is more efficacious than treatment with PTH alone for increasing bone mass and strength and improving trabecular microarchitecture in osteopenic OVX rats.

scholarly journals Effects of h-PTH on cancellous bone mass, connectivity, and bone strength in ovariectomized rats with and without sciatic-neurectomy

2004 ◽  
Vol 22 (3) ◽  
pp. 457-464 ◽  
Author(s):  
Y. Kasukawa ◽  
N. Miyakoshi ◽  
E. Itoi ◽  
T. Tsuchida ◽  
Y. Tamura ◽  
...  
Keyword(s):  
Bone Mass ◽  
Bone Strength ◽  
Cancellous Bone ◽  
Ovariectomized Rats ◽  
Sciatic Neurectomy

Zoledronic acid modulates osteoclast apoptosis through activation of the NF-κB signaling pathway in ovariectomized rats

2021 ◽  
pp. 153537022110110
Author(s):  
Yu-Ting Cheng ◽  
Jian Liao ◽  
Qian Zhou ◽  
Hua Huo ◽  
Lucas Zellmer ◽  
...  
Keyword(s):  
Zoledronic Acid ◽  
Bone Mass ◽  
Mass Loss ◽  
Ovariectomized Rats ◽  
Therapeutic Effects ◽  
Bone Mass Loss ◽  
Cellular Effects ◽  
Protein Levels ◽  
Adverse Factor ◽  
Osteoclast Apoptosis

Bone mass loss (osteoporosis) seen in postmenopausal women is an adverse factor for implant denture. Using an ovariectomized rat model, we studied the mechanism of estrogen-deficiency-caused bone loss and the therapeutic effect of Zoledronic acid. We observed that ovariectomized-caused resorption of bone tissue in the mandible was evident at four weeks and had not fully recovered by 12 weeks post-ovariectomized compared with the sham-operated controls. Further evaluation with a TUNEL assay showed ovariectomized enhanced apoptosis of osteoblasts but inhibited apoptosis of osteoclasts in the mandible. Zoledronic acid given subcutaneously as a single low dose was shown to counteract both of these ovariectomized effects. Immunohistochemical staining showed that ovariectomized induced the protein levels of RANKL and the 65-kD subunit of the NF-κB complex mainly in osteoclasts, as confirmed by staining for TRAP, a marker for osteoclasts, whereas zoledronic acid inhibited these inductions. Western blotting showed that the levels of RANKL, p65, as well as the phosphorylated form of p65, and IκB-α were all higher in the ovariectomized group than in the sham and ovariectomized + zoledronic acid groups at both the 4th- and 12th-week time points in the mandible. These data collectively suggest that ovariectomized causes bone mass loss by enhancing apoptosis of osteoblasts and inhibiting apoptosis of osteoclasts. In osteoclasts, these cellular effects may be achieved by activating RANKL-NF-κB signalling. Moreover, zoledronic acid elicits its therapeutic effects in the mandible by counteracting these cellular and molecular consequences of ovariectomized.

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