scholarly journals Effect of Risedronate on the Cortical and Cancellous Bone Mass and Mechanical Properties in Ovariectomized Rats: A Comparison with the Effects of Alfacalcidol

2006 ◽  
Vol 52 (6) ◽  
pp. 393-401 ◽  
Author(s):  
Jun IWAMOTO ◽  
Azusa SEKI ◽  
Tsuyoshi TAKEDA ◽  
Yoshihiro SATO ◽  
Harumoto YAMADA ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Mass ◽  
Cancellous Bone ◽  
Ovariectomized Rats

scholarly journals Negligible Effect of Estrogen Deficiency on Development of Skeletal Changes Induced by Type 1 Diabetes in Experimental Rat Models

2020 ◽  
Vol 2020 ◽  
pp. 1-21
Author(s):  
Aleksandra Janas ◽  
Ewa Kruczek ◽  
Piotr Londzin ◽  
Sławomir Borymski ◽  
Zenon P. Czuba ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bone Resorption ◽  
Bone Mass ◽  
Cancellous Bone ◽  
Maximum Load ◽  
Estrogen Deficiency ◽  
Female Rats ◽  
Skeletal System ◽  
Tibial Metaphysis ◽  
Ovx Rats

Although postmenopausal osteoporosis often occurs concurrently with diabetes, little is known about interactions between estrogen deficiency and hyperglycemia in the skeletal system. In the present study, the effects of estrogen deficiency on the development of biochemical, microstructural, and mechanical changes induced by streptozotocin-induced diabetes mellitus (DM) in the rat skeletal system were investigated. The experiments were carried out on nonovariectomized (NOVX) and ovariectomized (OVX) control and diabetic mature female Wistar rats. Serum levels of bone turnover markers (CTX-I and osteocalcin) and 23 cytokines, bone mass and mineralization, histomorphometric parameters, and mechanical properties of cancellous and compact bone were determined. The results were subjected to two-way ANOVA and principal component analysis (PCA). Estrogen deficiency induced osteoporotic changes, with increased bone resorption and formation, and worsening of microstructure (femoral metaphyseal BV/TV decreased by 13.0%) and mechanical properties of cancellous bone (the maximum load in the proximal tibial metaphysis decreased by 34.2%). DM in both the NOVX and OVX rats decreased bone mass, increased bone resorption and decreased bone formation, and worsened cancellous bone microarchitecture (for example, the femoral metaphyseal BV/TV decreased by 17.3% and 18.1%, respectively, in relation to the NOVX controls) and strength (the maximum load in the proximal tibial metaphysis decreased by 35.4% and 48.1%, respectively, in relation to the NOVX controls). Only in the diabetic rats, profound increases in some cytokine levels were noted. In conclusion, the changes induced by DM in female rats were only slightly intensified by estrogen deficiency. Despite similar effects on bone microstructure and strength, the influence of DM on the skeletal system was based on more profound systemic homeostasis changes than those induced by estrogen deficiency.

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
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