Effect of low molecular weight heparin (dalteparin) and fondaparinux (Arixtra) on human osteoblasts in vitro.
BACKGROUND
The prolonged administration of heparin for prevention and treatment of venous thromboembolism has been associated with a risk of heparin-induced osteoporosis. Fondaparinux is a new antithrombotic drug that specifically inhibits factor Xa. Because of the known interactions of other antithrombotic agents with bone remodelling, the effects of fondaparinux on human osteoblasts were analysed in vitro.


METHODS
Primary human osteoblast cell cultures were incubated with either the low molecular weight heparin dalteparin at concentrations of 30, 300 and 900 microg/ml or with fondaparinux at concentrations of 25, 50, 100, 150, 200 and 250 microg/ml. Cellular proliferation rate and protein synthesis were measured. Expression of genes encoding osteocalcin, collagen type I and alkaline phosphatase was examined by reverse transcriptase-polymerase chain reaction.


RESULTS
Incubation with dalteparin led to a significant, dose-dependent inhibition of osteoblast proliferation, inhibition of protein synthesis, and inhibited expression of phenotype markers (osteocalcin and alkaline phosphatase genes) after 3 and 7 days. No inhibitory effects were observed in the fondaparinux-treated cells.


CONCLUSIONS
Fondaparinux did not inhibit osteoblast proliferation in vitro and may reduce the risk of heparin-induced osteoporosis associated with long-term heparin administration.
Handschin
A E
AE
Division of Trauma Surgery and Research Division, University of Zurich, Zurich Switzerland and Section of Accident and Reconstructive Surgery, University of Heidelberg, Heidelberg, Germany
Trentz
O A
OA
Hoerstrup
S P
SP
Kock
H J
HJ
Wanner
G A
GA
Trentz
O
O
D000469:Alkaline Phosphatase / Q000378:metabolism; D000925:Anticoagulants / Q000009:adverse effects / Q000627:therapeutic use; D002478:Cells, Cultured; D017985:Dalteparin / Q000009:adverse effects*; D005452:Fluoresceins; D000077425:Fondaparinux; D015870:Gene Expression; D006801:Humans; D010006:Osteoblasts / Q000187:drug effects* / Q000378:metabolism; D015675:Osteocalcin / Q000378:metabolism; D010024:Osteoporosis / Q000139:chemically induced* / Q000517:prevention & control; D011134:Polysaccharides / Q000627:therapeutic use*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D012307:Risk Factors; D013923:Thromboembolism / Q000517:prevention & control*
D000925:Anticoagulants; D005452:Fluoresceins; D011134:Polysaccharides; D015675:Osteocalcin; D000469:Alkaline Phosphatase; D000077425:Fondaparinux; D017985:Dalteparin; C018506:diacetylfluorescein