Effect of combined humanPTH(1–34) and calcitonin treatment in ovariectomized rats

Washimi, Yuki; Ito, Masato; Morishima, Yosuke; Taguma, Kanako; Ojima, Yoshihide; Uzawa, Toyonobu; Hori, Masayuki

doi:10.1016/j.bone.2007.06.019

Cited by 21 publications

(21 citation statements)

References 30 publications

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“…This work has examined a range of mechanical properties with a sample population that is larger than that often used in these studies. Commonly in small animal studies that examine the influence of different biological factors, the number of samples for each group ranges from 6-13 [54][55][56][57][58][59][60][61]. The results of this study can be used to then estimate what magnitude of differences can be detected at a statistically significant level for these properties.…”

Section: Discussionmentioning

confidence: 99%

Measurement of the toughness of bone: A tutorial with special reference to small animal studies

Ritchie

Koester

Ionova

et al. 2008

Bone

196

214

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Quantitative assessment of the strength and toughness of bone has become an integral part of many biological and bioengineering studies on the structural properties of bone and their degradation due to aging, disease and therapeutic treatment. Whereas the biomechanical techniques for characterizing bone strength are well documented, few studies have focused on the theory, methodology, and various experimental procedures for evaluating the fracture toughness of bone, i.e., its resistance to fracture, with particular reference to whole bone testing in small animal studies. In this tutorial, we consider the many techniques for evaluating toughness and assess their specific relevance and application to the mechanical testing of small animal bones. Parallel experimental studies on wild-type rat and mouse femurs are used to evaluate the utility of these techniques and specifically to determine the coefficient of variation of the measured toughness values.

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Section: Discussionmentioning

confidence: 99%

Measurement of the toughness of bone: A tutorial with special reference to small animal studies

Ritchie

Koester

Ionova

et al. 2008

Bone

196

214

View full text Add to dashboard Cite

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“…The key effects observed in the first, and most detailed of these studies (Mosekilde et al 1994), was a more rapid increase in bone mass with combination therapy that was not sustained; long-term combination therapy did not differ from the result of PTH treatment alone, indicating that PTH anabolic action is not limited by osteoclast inactivation. In one study, the effects of PTH on mineralising surface were inhibited, indicating that the combination of the two treatments resulted in an antiresorptive effect overall, rather than enhanced anabolism (Washimi et al 2007). In contrast to those studies, the very low dose of CT used in the current study was deliberately chosen to be insufficient to prevent or reverse ovariectomy-induced bone loss, but chosen to transiently inhibit osteoclast activity at the time of PTH administration.…”

Section: Discussionmentioning

confidence: 99%

“…Co-administration of sCT with hPTH(1-34) has been reported previously in adult and aged OVX rats; however, the main focus of these earlier works was quite different, to explore whether PTH anabolic action could be enhanced by combining it with osteoclast inhibition (Mosekilde et al 1994, Li et al 1995, DeLuca & Dani 2001, Washimi et al 2007). In each of those studies, high doses of sCT (ten-to 30-fold higher than the current study) were used with the aim of increasing bone mass by suppressing osteoclast activity.…”

Section: Discussionmentioning

confidence: 99%

Decline in calcitonin receptor expression in osteocytes with age

Gooi

Chia

Walsh

et al. 2014

Journal of Endocrinology

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We have previously shown that co-administration of the transient osteoclast inhibitor, salmon calcitonin (sCT), blunts the anabolic effect of parathyroid hormone (PTH) in young rats and increases osteocytic expression of the bone formation inhibitor sclerostin (Sost). To determine whether this also occurs in adult animals, we co-administered sCT with PTH to 6-month-old sham-operated (SHAM) and ovariectomised (OVX) rats. While sCT reduced the stimulatory effect of PTH on serum amino-terminal propeptide of type 1 procollagen levels, in contrast to its influence in young rats, sCT did not reduce the anabolic effect of PTH on femoral bone mineral density, tibial trabecular bone volume or bone formation rate in 6-month-old SHAM or OVX rats. Quantitative real-time PCR analysis of femoral metaphyses collected 1 and 4 h after a single PTH injection confirmed a significant increase in mRNA levels for interleukin 6 (Il6) and ephrinB2 (EfnB2), and a significant reduction in Sost and dentin matrix protein-1 (Dmp1) in response to PTH. However, in contrast to observations in young rats, these effects were not modified by co-administration of sCT, nor did sCT significantly modify Sost, Dmp1, or matrix extracellular phosphoglycoprotein (Mepe) mRNA levels. Furthermore, while CT receptor (CTR) mRNA (Calcr) was readily detected in GFPC osteocytes isolated from young (3-week-old) DMP1-GFP mice, Calcr levels in osteocytes declined as mice aged, reaching levels that were undetectable in long bone at 49 weeks of age. These data indicate that osteocyte-mediated responses to CT are most likely to be of physiological relevance in young rodents.

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“…Washimi et al [31] reported significant differences in the four parameters of the trabecular bone microarchitecture of the distal femoral metaphysis, as follows: BV/TV = −58.1%, TbTh = −13.0%, TbSp = +200.0%, and TbN = −56.9%. Similarly, our experimental results revealed significant differences in these parameters of the trabecular bone microarchitecture of the femoral head, as follows: BV/TV = −29.9%, TbTh = −11.9%, TbSp = +26.5%, and TbN = −17.2%.…”

Section: Discussionmentioning

confidence: 99%

“…Another reason may be related to the regions measured by micro-CT. Previous studies have measured the trabecular bone microarchitecture of the distal femoral metaphysis [31, 32], whereas the trabecular bone microarchitecture of the femoral head was measured in the present study. Despite these differences, similar to previous studies, we observed that the BMD in the trabecular bone of the OVX group was significantly lower than that in the healthy group.…”

Section: Discussionmentioning

confidence: 99%

Intermittent parathyroid hormone improve bone microarchitecture of the mandible and femoral head in ovariectomized rats

Chen

Wang

Cheng

et al. 2017

BMC Musculoskelet Disord

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BackgroundIntermittent parathyroid hormone (PTH) can be used to treat osteoporosis of the spine and hip. However, whether it can be used to treat osteoporosis of the mandible is unclear. The purpose of this study was to explore the influence of applying intermittent PTH to ovariectomized rats on the trabecular bone microarchitecture of the mandible and femoral head.MethodsEighteen female rats were divided into three groups: the healthy group, ovariectomized (OVX) group, and OVX + PTH group. The OVX group and OVX + PTH group had an OVX at 8 weeks of age. The OVX + PTH group received intermittent PTH therapy for 12 weeks. The mandibles and femurs of all rats were removed at 20 weeks and were then scanned using microcomputed tomography (micro-CT).ResultsFrom the micro-CT analysis, the trabecular bone microarchitecture of the mandible and femoral head are offered as follows: (1) The bone volume fraction and trabecular thickness in the OVX group were lower than those in the healthy group. (2) The bone volume fraction and trabecular thickness in the OVX + PTH group approximated those in the healthy group.ConclusionThe conclusions of this study regarding the trabecular bone microarchitecture of the mandible and femoral head are offered as follows: (1) The BV/TV and TbTh in the OVX group were lower than those in the healthy group. (2) The BV/TV and TbTh in the OVX + PTH group approximated those in the healthy group, therefore, intermittent PTH displayed high efficacy for treating femoral or mandibular deterioration of bone microstructure resulting from loss of ovarian function. Osteoporosis of the femur or mandible in the rats was ameliorated by intermittent PTH therapy.

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Effect of combined humanPTH(1–34) and calcitonin treatment in ovariectomized rats

Cited by 21 publications

References 30 publications

Measurement of the toughness of bone: A tutorial with special reference to small animal studies

Measurement of the toughness of bone: A tutorial with special reference to small animal studies

Decline in calcitonin receptor expression in osteocytes with age

Intermittent parathyroid hormone improve bone microarchitecture of the mandible and femoral head in ovariectomized rats

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