5 alpha-Dihydrotestosterone partially restores cancellous bone volume in osteopenic ovariectomized rats

1994 ◽  
Vol 267 (6) ◽  
pp. E853-E859 ◽  
Author(s):  
J. H. Tobias ◽  
A. Gallagher ◽  
T. J. Chambers
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Bone Formation ◽  
Cancellous Bone ◽  
Bone Growth ◽  
Bone Volume ◽  
Ovariectomized Rats ◽  
Trabecular Thickness ◽  
Longitudinal Bone Growth ◽  
Periosteal Bone Formation

Although androgens are thought to be important for skeletal maintenance in females and males, little is known about the mechanisms involved. To investigate this question further, we examined the effects of administering 0.01, 0.1, or 1.0 mg/kg 5 alpha-dihydrotestosterone (DHT) for 60 days on the skeleton of ovariectomized rats. Treatment was delayed until 90 days after ovariectomy to enable bone loss to stabilize. We found that ovariectomy markedly reduced cancellous bone volume of the proximal tibial metaphysis due to a combination of loss and thinning of trabeculae. Cancellous bone volume was partially restored by all doses of DHT, with trabecular thickness, but not number, returning to that of sham-operated animals. DHT also stimulated longitudinal bone growth and endosteal and periosteal bone formation and suppressed histomorphometric indexes of cancellous bone resorption. This suggests that DHT influences skeletal metabolism in osteopenic ovariectomized rats both by stimulating bone formation and suppressing resorption, although it is unclear which, if any, of these actions predominate at cancellous sites.

scholarly journals Prolonged low-dose infusion of human parathyroid hormone does not increase femoral cancellous bone volume in ovariectomized rats

1999 ◽  
pp. 70-74 ◽  
Author(s):  
P Morley ◽  
JF Whitfield ◽  
GE Willick ◽  
V Ross ◽  
S MacLean ◽  
...  
Keyword(s):  
Parathyroid Hormone ◽  
Cancellous Bone ◽  
Oral Delivery ◽  
Bone Growth ◽  
Bone Volume ◽  
Ovariectomized Rats ◽  
Low Doses ◽  
Human Parathyroid Hormone ◽  
Trabecular Thickness ◽  
Trabecular Number

OBJECTIVE: Daily injections of human parathyroid hormone (hPTH) increase bone volume in various animal species and in osteoporotic women. For hPTH to be widely accepted as an anabolic therapy for treating postmenopausal osteoporosis alternative delivery options need to be explored to replace the need for daily patient subcutaneous self-injection. Among these are inhalation, oral delivery and the use of programmable implanted minipumps to deliver the peptide. While infusion of high doses of PTH causes bone loss and hypercalcemia, no studies have assessed the effects of prolonged infusion of low doses of PTH on bone growth. DESIGN AND METHODS: [Leu(27)]-cyclo(Glu(22)-Lys(26))-hPTH-(1--31)NH(2) was delivered by Alzet minipumps to ovariectomized rats for 6 weeks after which histomorphometric indices (cancellous bone volume, trabecular thickness, mean trabecular number) of bone formation were measured in distal femurs. RESULTS: Infusing low doses (0.05 and 0.1 nmole/100g body weight/day) of the hPTH analog, [Leu(27)]-cyclo(Glu(22)-Lys(26))-hPTH-(1--31)NH(2), for 6 weeks does not prevent the ovariectomy-induced loss of rat femoral cancellous bone volume, trabecular thickness or trabecular number. CONCLUSION: These results support the absolute requirement of daily injections for the osteogenic action of hPTH on bone.

Running exercise alleviates trabecular bone loss and osteopenia in hemizygous β-globin knockout thalassemic mice

2014 ◽  
Vol 306 (12) ◽  
pp. E1406-E1417 ◽  
Author(s):  
Kanogwun Thongchote ◽  
Saovaros Svasti ◽  
Jarinthorn Teerapornpuntakit ◽  
Nateetip Krishnamra ◽  
Narattaphol Charoenphandhu
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Bone Formation ◽  
Trabecular Bone ◽  
Elevated Serum ◽  
Bone Volume ◽  
Trabecular Bone Volume ◽  
Mineral Density ◽  
Trabecular Thickness ◽  
Running Exercise

A marked decrease in β-globin production led to β-thalassemia, a hereditary anemic disease associated with bone marrow expansion, bone erosion, and osteoporosis. Herein, we aimed to investigate changes in bone mineral density (BMD) and trabecular microstructure in hemizygous β-globin knockout thalassemic (BKO) mice and to determine whether endurance running (60 min/day, 5 days/wk for 12 wk in running wheels) could effectively alleviate bone loss in BKO mice. Both male and female BKO mice (1–2 mo old) showed growth retardation as indicated by smaller body weight and femoral length than their wild-type littermates. A decrease in BMD was more severe in female than in male BKO mice. Bone histomorphometry revealed that BKO mice had decreases in trabecular bone volume, trabecular number, and trabecular thickness, presumably due to suppression of osteoblast-mediated bone formation and activation of osteoclast-mediated bone resorption, the latter of which was consistent with elevated serum levels of osteoclastogenic cytokines IL-1α and -1β. As determined by peripheral quantitative computed tomography, running increased cortical density and thickness in the femoral and tibial diaphyses of BKO mice compared with those of sedentary BKO mice. Several histomorphometric parameters suggested an enhancement of bone formation (e.g., increased mineral apposition rate) and suppression of bone resorption (e.g., decreased osteoclast surface), which led to increases in trabecular bone volume and trabecular thickness in running BKO mice. In conclusion, BKO mice exhibited pervasive osteopenia and impaired bone microstructure, whereas running exercise appeared to be an effective intervention in alleviating bone microstructural defect in β-thalassemia.

Intermittent retinoie acid in combination with continuous oestradiol-17β increases cancellous bone volume in osteopaenic ovariectomized rats

1994 ◽  
Vol 142 (1) ◽  
pp. 61-67 ◽  
Author(s):  
J H Tobias ◽  
A Gallagher ◽  
T J Chambers
Keyword(s):  
Retinoic Acid ◽  
Bone Resorption ◽  
Bone Formation ◽  
Cancellous Bone ◽  
Bone Volume ◽  
Ovariectomized Rats ◽  
Prolonged Treatment ◽  
Term Administration ◽  
Coupling Mechanisms ◽  
Sustained Increase

Abstract Although short-term administration of oestradiol-17β (OE2) stimulates cancellous bone formation in the rat, this is replaced by a tendency to suppression after prolonged treatment. Hence, in rats rendered osteopaenic by ovariectomy, OE2 administration fails either to induce a sustained increase in bone formation or to restore bone volume. A possible explanation for this failure is that OE2 also inhibits bone resorption, secondarily suppressing bone formation through coupling mechanisms. We therefore investigated whether the effects of OE2 treatment might be modified by intermittently stimulating bone resorption with retinoic acid (120mg/kg daily) for 4 out of every 20 days. We found, in a preliminary experiment using intact animals, that intermittent retinoic acid reduced cancellous bone volume, consistent with previously documented stimulation of bone resorption by retinoic acid. Rats were then rendered osteopaenic by ovariectomy, and given vehicle, retinoic acid and/or OE2. We found that animals treated with intermittent retinoic acid and OE2 showed a substantial increase in cancellous bone volume compared with ovariectomized animals treated with vehicle, retinoic acid alone or OE2 alone. Therefore, intermittent retinoic acid appears to cause a net increase in bone formation over resorption when given to ovariectomized animals in conjunction with OE2. We conclude that the effects of OE2 on cancellous bone are modified by intermittent treatment with retinoic acid, resulting in a substantial increase in bone volume. Journal of Endocrinology (1994) 142, 61–67

The effects of ovarian transplantation on bone loss in ovariectomized rats

1994 ◽  
Vol 142 (1) ◽  
pp. 187-192 ◽  
Author(s):  
J H Tobias ◽  
T J Chambers ◽  
A Gallagher
Keyword(s):  
Bone Loss ◽  
Cancellous Bone ◽  
Ovarian Function ◽  
Hormone Replacement ◽  
Bone Volume ◽  
Ovariectomized Rats ◽  
Vaginal Smears ◽  
Trabecular Thickness ◽  
Ovarian Transplantation ◽  
Trabecular Number

Abstract Although hormone replacement therapy can prevent postmenopausal bone loss, it does not restore bone mass to normal in patients with established osteoporosis. This might reflect a failure to reproduce certain aspects of gonadal function. One method of investigating this possibility would be to examine the effect of ovarian transplantation on the skeleton of osteopaenic ovariectomized rats. However, ovarian transplantation may not fully restore ovarian function to normal, and it is not known whether transplanted ovaries reproduce the action of native ovaries on the skeleton. Therefore, we investigated whether renal capsular or subcutaneous ovarian transplants prevent the effects of ovariectomy on histomorphometric indices of rat tibiae over 44 days. Daily vaginal smears showed that oestrous cycles returned in all but two of 25 animals receiving ovarian transplants. We found that ovarian transplantation prevented the reduction in cancellous bone volume following ovariectomy. While trabecular number was reduced in ovariectomized animals receiving renal capsular ovarian transplants compared to intact animals, trabecular thickness was increased in both transplant groups. Ovarian transplantation also prevented the increase in cancellous and cortical bone formation, cancellous bone resorption and longitudinal growth rate caused by ovariectomy. We conclude that restoration of ovarian function by ovarian transplantation largely prevents the effects of ovariectomy on histomorphometric indices of rat tibiae, suggesting that transplanted ovaries can substitute for the action of native ovaries on the skeleton. Journal of Endocrinology (1994) 142, 187–192

Physiological plasma levels of androgens reduce bone loss in the ovariectomized rat

1998 ◽  
Vol 274 (2) ◽  
pp. E328-E335 ◽  
Author(s):  
C. K. Lea ◽  
A. M. Flanagan
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Protective Effect ◽  
Cancellous Bone ◽  
Plasma Levels ◽  
Slow Release ◽  
Bone Volume ◽  
Ovariectomized Rat ◽  
Ovx Rats ◽  
Reduce Bone Loss

The effect of androstenedione (ADIONE) slow-release pellets on cancellous bone volume (BV/TV) at the tibial metaphysis was investigated in ovariectomized (OVX) rats at various times from 21 to 180 days. Plasma levels of ADIONE and testosterone (T) in OVX rats were significantly reduced at 21 days and were restored close to levels in the sham rats with the 1.5-mg ADIONE pellet. OVX animals with and without ADIONE pellets resulted in close to a 50% reduction in BV/TV by day 21. By day 180, OVX rats had only ∼5% BV/TV, whereas that in ADIONE-treated OVX rats was significantly greater at ∼12%. The reduced BV/TV was associated with increased bone resorption and formation. In a separate 90-day experiment, we found that the antiandrogen, Casodex, abrogated the ADIONE-induced skeletal-protective effect in OVX rats, whereas the antiaromatase, Arimidex, had no effect. This provides evidence that ADIONE protects against the development of osteopenia in the estrogen-deficient rat and mediates its effect through androgens and not estrogens.

Adverse effects of strenuous exercise: a densitometric and histomorphometric study in the rat

1994 ◽  
Vol 76 (5) ◽  
pp. 1999-2005 ◽  
Author(s):  
S. Bourrin ◽  
C. Genty ◽  
S. Palle ◽  
C. Gharib ◽  
C. Alexandre
Keyword(s):  
Bone Mineral Density ◽  
Bone Loss ◽  
Bone Mineral ◽  
Cancellous Bone ◽  
Bone Growth ◽  
Proximal Tibia ◽  
Bone Volume ◽  
Mineral Density ◽  
Osteoblastic Activity ◽  
Tibia Length

To investigate the manner in which cancellous bone in different skeletal sites and within a bone site adapts to strenuous training, 5-wk-old male rats were subjected to intensive treadmill running [80% of maximal O2 consumption (VO2max)] for 11 wk. VO2max, tibia length, and bone mineral density were measured. Histomorphometric analysis was performed in the epiphysis, primary spongiosa (1 zero sp) and secondary spongiosa (2 zero sp) of the contralateral proximal tibia, and the 2 zero sp of thoracic and lumbar vertebrae. VO2max was increased by 39%. No changes were observed in vertebrae. Tibia length, 1 zero sp bone volume, and number of trabeculae were significantly decreased, indicating a retarded longitudinal bone growth. Bone mineral density in the proximal tibia was significantly decreased. In the epiphysis, a trabecular thinning and an increase of trabecular number were shown. In the 2 zero sp, bone volume and number of trabeculae were significantly decreased. The increased total eroded surfaces could indicate an early but transient increase in bone resorption activity. Osteoid thickness was reduced, whereas osteoclast number and osteoid surfaces were unchanged, suggesting that the observed bone loss was mostly due to an impaired osteoblastic activity. In conclusion, 1) strenuous training in young rats reduces longitudinal bone growth and induces bone loss, 2) the cancellous bone adaptation is site specific, and 3) the bone loss is mainly due to decreased osteoblastic activity rather than a global adaptation of bone remodeling.

Distinct effects of ovarian transplantation and exogenous 17 β-oestradiol on cancellous bone of osteopenic ovariectomized rats

1995 ◽  
Vol 133 (4) ◽  
pp. 483-488 ◽  
Author(s):  
Andrea C Gallagher ◽  
Timothy J Chambers ◽  
Jonathan H Tobias
Keyword(s):  
Bone Loss ◽  
Bone Metabolism ◽  
Cancellous Bone ◽  
Ovarian Function ◽  
Bone Volume ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Serum Progesterone ◽  
Ovarian Transplantation ◽  
Ovx Rats

Gallagher AC, Chambers TJ, Tobias JH. Distinct effects of ovarian transplantation and exogenous 17 β-oestradiol on cancellous bone of osteopenic ovariectomized rats. Eur J Endocrinol 1995;133:483–8. ISSN 0804–4643 Although 17 β-oestradiol (E2) is known to prevent bone loss, prolonged administration of E2 is unable to reverse this in female rats rendered osteopenic by ovariectomy. To determine whether this reflects a failure to replace other components of ovarian function involved in bone metabolism, we compared the effects of administering E2 to osteopenic ovariectomized (ovx) rats with those of ovarian transplantation. Ovariectomy was performed in female rats. After 13 weeks, by which time marked bone loss had occurred, one group of ovx animals received ovaries from donor rats, and, after a delay of 2 weeks to allow oestrus cycles to return, a further group received E2 5 μg · kg−1 · day−1 for 9 weeks. The dose of E2 was chosen as that which in preliminary studies restored mean serum E2 levels to that of intact female rats. The study was terminated 24 weeks after ovariectomy. Both E2 and ovarian transplantation largely restored indices of oestrogenic exposure in ovx rats to those of sham-ovx animals. Animals receiving ovarian transplants also showed a small increase in serum progesterone and full restoration of serum testosterone. However, while ovarian transplantation also returned indices of cancellous bone metabolism to those of sham-ovx animals, there was little increase in bone volume. Interestingly, exogenous E2 caused a greater increase in cancellous bone volume than ovarian transplantation but also caused more marked suppression of bone formation, as assessed at the end of the study. In conclusion, exogenous E2 and ovarian transplantation exerted distinct effects on skeletal metabolism in osteopenic ovx rats, although the basis for this difference is currently unclear. JH Tobias, Department of Histopathology, St George's Hospital Medical School, London SW17 ORE, UK

scholarly journals Bone Histomorphometric Findings in Ankylosing Spondylitis: A Case Report

2018 ◽  
Vol 4 (1) ◽  
pp. 132-137 ◽  
Author(s):  
Naoki Kondo ◽  
Noriaki Yamamoto ◽  
Kei Watanabe ◽  
Naoto Endo
Keyword(s):  
Alkaline Phosphatase ◽  
Ankylosing Spondylitis ◽  
Bone Resorption ◽  
Bone Formation ◽  
Bone Turnover ◽  
Reference Values ◽  
Bone Volume ◽  
Bone Surface ◽  
Trabecular Thickness ◽  
Low Bone Turnover

There is minimal information on bone Histomorphometric characteristics in ankylosing spondylitis. We here report a case of a 36-year-old Japanese male that suffered from lumbago and could not gaze in the forward direction. Ultimately, a diagnosis of ankylosing spondylitis was made, and vertebroplasty was performed to correct the third lumbar spine. Histomorphometry of the iliac bone showed reduced bone volume parameters (bone volume, and trabecular thickness and width) than reference values. In addition, bone formation parameters (osteoid thickness and osteoblast surface per bone surface) and bone resorption parameters (eroded surface per bone surface and osteoclast number per bone surface) were also lower than reference values, indicating low bone turnover. By contrast, there was not a clear trend in bone resorption markers: bone- pecific alkaline phosphatase (17 U/l) was normal, TRACP-5b (136 mU/dl) was slightly lower, urinary N-terminal telopeptide (45.3 nmol BCE/mmol Cr) was normal, and deoxypyridinoline (9.1 nM/mM Cre) was higher than reference values. However, there was deficiency in 25-hydroxy vitamin D (25-OH-D; 14.4 ng/ml). This case highlights the rare possibility of performing bone histomorphometry, and indicates that a low bone volume and low bone turnover (in both bone formation and resorption) are characteristics of ankylosing spondylitis, although bone formation markers (bone-specific alkaline phosphatase) and bone mineral density are within the normal range. The possibility of a serum 25-OH-D deficient status in ankylosing spondylitis should be further considered.

PRECLINICAL STUDIES OF ALENDRONATE

1999 ◽  
Vol 03 (03) ◽  
pp. 209-216
Author(s):  
Jenny Zhao ◽  
Yebin Jiang ◽  
Harry K. Genant
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Bone Formation ◽  
Bone Turnover ◽  
Trabecular Bone ◽  
Bending Strength ◽  
Bone Volume ◽  
Prostaglandin E ◽  
Dependent Manner ◽  
Dose Dependent

Alendronate has been developed for the treatment of diseases characterized by increased bone resorption, such as osteoporosis. It increases metaphyseal bone density, bone volume, femoral bending strength and vertebral compressive strength, in a dose-dependent manner, in growing, intact rats. In ovariectomized (OVX) rats, alendronate increases femoral bone mass and tibial trabecular bone volume in a dose-dependent manner, and increases femoral midshaft bending strength. In rats immobilized by unilateral sciatic neurectomy, it inhibits bone loss and is dose-dependent. In rats, alendronate prevents high-turnover osteopenia induced by hyperthyroidism or by administration of immunosuppressant agent cyclosporin-A. Also in rats, treatment with prostaglandin E 2 and alendronate does not inhibit prostaglandin E 2-induced stimulation of bone formation on endocortical and periosteal surfaces. It does, however, prevent prostaglandin E 2-induced cortical bone porosity as a result of increased bone resorption, leading to an increase in cortical thickness and an increase in three-point bending strength of the femoral midshaft. At up to five times the dose used for treatment of osteoporosis in clinical trials, alendronate causes no abnormalities in bone remodeling, bone structure, or structural mechanical properties of the femur or vertebrae in intact beagles. Treatment with alendronate before or during fracture healing, or both, has no adverse effects on the union, strength, bone formation or mineralization of bone in mature beagle dogs. In intact minipigs, sodium fluoride increases and alendronate decreases bone turnover, while sodium fluoride, but not alendronate, decreases L4 strength and femoral stiffness. Small-angle X-ray scattering and backscattered electron imaging show that the trabecular bone matrix is more uniformly mineralized after alendronate treatment. In OVX baboons, which show bone changes similar to those seen in postmenopausal women, alendronate prevents an increase in bone turnover, and increases both bone volume and strength in vertebrae, in a dose-dependent manner. Alendronate also reduces the bone loss of alveolar support associated with periodontitis in monkeys. Thus, alendronate inhibits bone resorption and bone turnover, increases bone quantity accompanied by improved bone quality in some of the intact animals and in the animal models.

scholarly journals Green Tomato Extract Prevents Bone Loss in Ovariectomized Rats, a Model of Osteoporosis

Nutrients ◽  
2020 ◽  
Vol 12 (10) ◽  
pp. 3210
Author(s):  
Farida S. Nirmala ◽  
Hyunjung Lee ◽  
Ji-Sun Kim ◽  
Taeyoul Ha ◽  
Chang Hwa Jung ◽  
...  
Keyword(s):  
Bone Resorption ◽  
Bone Loss ◽  
Bone Formation ◽  
Postmenopausal Osteoporosis ◽  
Ovariectomized Rats ◽  
Bone Homeostasis ◽  
Sprague Dawley ◽  
Micro Computed Tomography ◽  
Tomato Extract ◽  
Ovx Rats

Although drug therapies are available for postmenopausal osteoporosis, these drugs are not free of side effects and long-term adherence to them are low. A safe and effective nutritional approach to counter postmenopausal osteoporosis is an important research goal. We fed ovariectomized (OVX) Sprague–Dawley rats a diet supplemented with 1% or 2% green tomato extract (GTE). After 12 weeks, micro-computed tomography scans revealed that GTE supplementation effectively prevented distal femur bone loss. This prevention was due to improved bone formation and suppressed bone resorption as observed by the regulation of osteoblast and osteoclast activities. GTE supplementation also improved bone formation through Bmp2-Smad 1/5/8-Runx2 signaling, while bone resorption was regulated by the receptor activator of nuclear factor kappa-B (RANKL)/osteoprogeterin (OPG) pathway. These results suggest that GTE supplementation prevents severe postmenopausal bone loss by maintaining the regulation of bone homeostasis in OVX rats. GTE as a diet supplement might be a potential novel alternative for the prevention of postmenopausal osteoporosis.

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