Zoledronate Pathway


The action of zoledronate on bone tissue is based partly on its affinity for hydroxyapatite, which is part of the mineral matrix of bone. Zoledronate also targets farnesyl pyrophosphate (FPP) synthase. Nitrogen-containing bisphosphonates such as zoledronate appear to act as analogues of isoprenoid diphosphate lipids, thereby inhibiting FPP synthase, an enzyme in the mevalonate pathway. Inhibition of this enzyme in osteoclasts prevents the biosynthesis of isoprenoid lipids (FPP and GGPP) that are essential for the post-translational farnesylation and geranylgeranylation of small GTPase signalling proteins. This activity inhibits osteoclast activity and reduces bone resorption and turnover. In postmenopausal women, it reduces the elevated rate of bone turnover, leading to, on average, a net gain in bone mass.

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References

  1. Reszka, A.A., & Rodan, G.A. (2003). Bisphosphonate mechanism of action. Current Rheumatology Reports, 5(1), 65-74. PMID: 12590887
  2. Seibel, M.J. (2004). Bone metabolism. In S. Offermanns, & W. Rosenthal (Eds.). Encyclopedic reference of molecular pharmacology (pp. 190-197). Berlin, Germany: Springer.