scholarly journals A Histomorphometric Comparison of the Effects of Heparin and Low-Molecular-Weight Heparin on Cancellous Bone in Rats

Blood ◽  
1997 ◽  
Vol 89 (9) ◽  
pp. 3236-3242 ◽  
Author(s):  
Jeffrey M. Muir ◽  
Jack Hirsh ◽  
Jeffrey I. Weitz ◽  
Maureen Andrew ◽  
Edward Young ◽  
...  

Abstract Long-term heparin treatment causes osteoporosis through, an as yet, undefined mechanism. To investigate this phenomenon and to determine the relative benefits of low-molecular-weight heparin (LMWH) use, we treated rats with once daily subcutaneous injections of either unfractionated heparin (1.0 U/g or 0.5 U/g), the LMWH, Tinzaparin (1.0 U/g or 0.5 U/g), or placebo (saline) for a period of 32 days. The effects on bone were then compared both histomorphometrically and biochemically by measuring urinary type I collagen cross-linked pyridinoline (PYD) and serum alkaline phosphatase, markers of bone resorption and formation, respectively. Histomorphometric analysis of the distal third of the right femur, in the region proximal to the epiphyseal growth plate, demonstrated that both heparin and LMWH decrease cancellous bone volume in a dose-dependent fashion, but that heparin causes significantly more cancellous bone loss than does LMWH. Although both heparin and LMWH decrease osteoblast and osteoid surface to a similar extent, only heparin increases osteoclast surface. In support of these histomorphometric findings, biochemical markers of bone turnover demonstrated that both heparin and LMWH treatment produce a dose-dependent decrease in serum alkaline phosphatase, consistent with reduced bone formation, whereas only heparin causes a transient increase in urinary PYD, consistent with an increase in bone resorption. Based on these observations, we conclude that heparin decreases cancellous bone volume both by decreasing the rate of bone formation and increasing the rate of bone resorption. In contrast, LMWH, causes less osteopenia than heparin because it only decreases the rate of bone formation.

Blood ◽  
1996 ◽  
Vol 88 (4) ◽  
pp. 1314-1320 ◽  
Author(s):  
JM Muir ◽  
M Andrew ◽  
J Hirsh ◽  
JI Weitz ◽  
E Young ◽  
...  

Long-term heparin treatment causes osteoporosis through an as yet undefined mechanism. To investigate this phenomenon, we treated rats with once daily subcutaneous injections of heparin (in doses ranging from 0.25 to 1.0 U/g) or saline for 8 to 32 days and monitored the effects on bone both histomorphometrically and by serial measurements of urinary type 1 collagen cross linked-pyridinoline (PYD) and serum alkaline phosphatase, markers of bone resorption and formation, respectively. Histomorphometric analysis of the distal third of the right femur in the region proximal to the epiphyseal growth plate showed that heparin induces both a time- and dose-dependent decreased in trabecular bone volume, with the majority of trabecular bone loss occurring within the first 8 days of treatment. Thus, heparin doses of 1.0 U/g/d resulted in a 32% loss of trabecular bone. Heparin-treated rats also showed a 37% decrease in osteoblast surface as well as a 75% decrease in osteoid surface. In contrast, heparin treatment had the opposite effect on osteoclast surface, which was 43% higher in heparin- treated rats, as compared with that in control rats. Biochemical markers of bone turnover showed that heparin treatment produced a dose- dependent decrease in serum alkaline phosphatase and a transient increase in urinary PYD, thus confirming the histomorphometric data. Based on these observations, we conclude that heparin decreases trabecular bone volume both by decreasing the rate of bone formation and increasing the rate of bone resorption.


1990 ◽  
Vol 63 (03) ◽  
pp. 505-509 ◽  
Author(s):  
Thomas Mätzsch ◽  
David Bergqvist ◽  
Ulla Hedner ◽  
Bo Nilsson ◽  
Per Østergaar

SummaryA comparison between the effect of low molecular weight heparin (LMWH) and unfragmented heparin (UH) on induction of osteoporosis was made in 60 rats treated with either UH (2 IU/ g b w), LMWH in 2 doses (2 Xal U/g or 0.4 Xal U/g) or placebo (saline) for 34 days. Studied variables were: bone mineral mass in femora; fragility of humera; zinc and calcium levels in serum and bone ash and albumin in plasma. A significant reduction in bone mineral mass was found in all heparin-treated rats. There was no difference between UH and LMWH in this respect. The effect was dose-dependent in LMWH-treated animals. The zinc contents in bone ash were decreased in all heparin-treated rats as compared with controls. No recognizable pattern was seen in alterations of zinc or calcium in serum. The fragility of the humera, tested as breaking strength did not differ between treatment groups and controls. In conclusion, if dosed according to similar factor Xa inhibitory activities, LMWH induces osteoporosis to the same extent as UH and in a dose-dependent manner. The zinc content in bone ash was decreased after heparin treatment, irrespective of type of heparin given.


1996 ◽  
Vol 2 (3) ◽  
pp. 209-212 ◽  
Author(s):  
Hanne B. Ravn ◽  
Claus Bregengaard ◽  
Henrik Vissinger ◽  
Per Østergaard ◽  
Jan Holst ◽  
...  

A low-molecular-weight heparin (LMWH), when anti-IIa activity was compared. In the ex vivo part Tinzaparin, was compared with unfractionated heparin of the study, a significant enhancement of ADP-induced (UFH) for their effects on platelet aggregation in vitro and platelet aggregation was observed after i.v. administra ex vivo. Both heparins showed a dose-dependent proag- tion of both Tinzaparin and UFH with no difference in gregatory effect on ADP- and collagen-induced platelet potency. Subcutaneous administration of Tinzaparin in aggregation in vitro, but LMWH was less potent. The two different doses did not have any effect on platelet differences in potency between Tinzaparin and UFH de- activity. In conclusion, Tinzaparin appears, like other pended on how the compounds were compared. The most LMWHs, to have less proaggregatory effect on platelets pronounced difference was found when molar concentra- than UFH both in vitro and ex vivo.


1997 ◽  
Vol 77 (04) ◽  
pp. 789-795 ◽  
Author(s):  
Yasuo Takahashi ◽  
Yoshitaka Hosaka ◽  
Kazunori Imada ◽  
Takehiro Adachi ◽  
Hiromi Niina ◽  
...  

SummaryWe compared the antithrombotic and hemorrhagic effects of naturally existing human urinary soluble thrombomodulin (MR-33) with those of low molecular weight heparin (LMW-heparin) in rats. In in vitro experiments, MR-33 prolonged APTT in a dose-dependent fashion; its effect in this respect was as potent as that of LMW-heparin, but it was less potent than unfractionated heparin (UF-heparin). MR-33 was effective on endotoxin- or thromboplastin-induced disseminated intravascular coagulation (DIC) in rats. In both DIC models, infusion of MR-33 improved hematological abnormalities compatible with DIC in a dose-dependent fashion without excessive prolongation effect on APTT. Although LMW-heparin and UF-heparin also improved both DIC models, excessive prolongation of APTT was observed at high doses. It is well-known that the excessive prolongation of APTT with antithrombotic drugs like heparins is an index for hemorrhage, which is a major side effect in the treatment of DIC. We therefore further compared the antithrombotic (Benefit: dose required for 50% inhibition of fibrinogen decrease: ED50) and hemorrhagic (Risk: minimum dose required for significant prolongation of bleeding time) effects of MR-33 and LMW-heparin in the thromboplastin-induced DIC model. As a result, Benefit-Risk ratio was 1:27 for MR-33 and 1:3 for LMW heparin. These results indicate that MR-33 may be a clinically useful antithrombotic agent with reduced risk for hemorrhage compared with LMW-heparin.


1994 ◽  
Vol 267 (6) ◽  
pp. E853-E859 ◽  
Author(s):  
J. H. Tobias ◽  
A. Gallagher ◽  
T. J. Chambers

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.


2000 ◽  
Vol 17 (2) ◽  
pp. 173-185 ◽  
Author(s):  
David Abrial ◽  
Alain Blanc ◽  
Mohamed Réhailia ◽  
Patrick Mismetti ◽  
Colette Bouchut ◽  
...  

2001 ◽  
Vol 85 (01) ◽  
pp. 114-118 ◽  
Author(s):  
Sandra Wice ◽  
Tilly Ping ◽  
Dieter Herr ◽  
Volker Laux ◽  
Linda Hiebert

SummaryPrevious studies in rats show that unfractionated heparin and the low molecular weight heparin logiparin have a dose-dependent antithrombotic effect and are found in endothelium and plasma when administered orally. Objectives of the present study were to determine if similar evidence of absorption could be observed with oral reviparin sodium. Thrombosis incidence was determined 4 h after application of 10% formalin in methanol to the exposed jugular vein. A dose-dependent antithrombotic effect was observed when 0.01 to 7.5 mg/kg (20 rats/group) was administered by stomach tube immediately following thrombus initiation. Thrombotic incidence was also significantly reduced when 0.025 mg/kg was given 4 and 2 h prior to, immediately after, and 2 and 3 h following thrombus initiation. Reviparin was recovered from endothelium and plasma in trace amounts at all doses. At 0.025 mg/kg, peak aortic endothelial reviparin concentrations were found at 1 and 2 h and peak plasma anti-Xa activity was detected at 2 h. Trace amounts of plasma TFPI were found only at 8 h after administration. Dose-dependent antithrombotic activity and recovery from endothelium and plasma support the hypothesis that orally administered reviparin sodium is absorbed.


1994 ◽  
Vol 142 (1) ◽  
pp. 61-67 ◽  
Author(s):  
J H Tobias ◽  
A Gallagher ◽  
T J Chambers

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


2018 ◽  
Vol 4 (1) ◽  
pp. 132-137 ◽  
Author(s):  
Naoki Kondo ◽  
Noriaki Yamamoto ◽  
Kei Watanabe ◽  
Naoto Endo

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.


1999 ◽  
Vol 03 (03) ◽  
pp. 209-216
Author(s):  
Jenny Zhao ◽  
Yebin Jiang ◽  
Harry K. Genant

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.


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