title: Comparative appraisal of clodronate, aspirin and dexamethasone as agents reducing alendronate-induced inflammation in a murine model.
abstract: Among the bisphosphonates, the nitrogen-containing bisphosphonates have much stronger anti-bone-resorptive activities than bisphosphonates containing no nitrogen, but nitrogen-containing bisphosphonates mostly have inflammatory side effects. Our previous murine-model experiments with a single intraperitoneal bisphosphonate injection demonstrated that (i) nitrogen-containing bisphosphonates induce various inflammatory reactions via an IL-1-dependent mechanism, (ii) alendronate (an nitrogen-containing bisphosphonate) produces a clear sclerotic line in the tibia that is easily detectable by radiography a few weeks later (tentatively called the bisphosphonate line, a useful marker for the anti-bone-resorptive activities of bisphosphonates), and (iii) clodronate (a non-nitrogen-containing bisphosphonate) reduces the inflammatory reactions induced by alendronate but does not reduce the bisphosphonate line formation induced by alendronate. We compared the effects of clodronate, aspirin and dexamethasone on the inflammatory reactions induced by alendronate (40 micromol/kg) (induction of the histamine-forming enzyme, accumulation of pleural exudate and splenomegaly) and on the bisphosphonate line formation induced by alendronate (0.1 micromol/kg). The effects of aspirin (833 micromol/kg) were weak. However, like clodronate, dexamethasone (10 micromol/kg, injected 5 min. after alendronate), strongly inhibited the alendronate-induced inflammatory reactions but did not reduce the alendronate-induced bisphosphonate line formation. Alendronate produced normal bisphosphonate lines in IL-1-deficient mice, too. These results suggest that clodronate and/or dexamethasone may be suitable for preventing or reducing the inflammatory side effects of nitrogen-containing bisphosphonates while preserving their powerful anti-bone-resorptive activities (although in practice the known side effects of dexamethasone may limit its use), and that the anti-bone resorptive activities of nitrogen-containing bisphosphonates are not influenced by IL-1.
authors.affiliation: Department of Molecular Regulation, Graduate School of Dentistry, Tohoku University, Seiryo-machi, Aoba-ku, Sendai 980-8575, Japan.
authors.forename: Zhiqian
authors.initials: Z
authors.lastname: Yu
authors.forename: Hiromi
authors.initials: H
authors.lastname: Funayama
authors.forename: Xue
authors.initials: X
authors.lastname: Deng
authors.forename: Toshinobu
authors.initials: T
authors.lastname: Kuroishi
authors.forename: Takashi
authors.initials: T
authors.lastname: Sasano
authors.forename: Shunji
authors.initials: S
authors.lastname: Sugawara
authors.forename: Yasuo
authors.initials: Y
authors.lastname: Endo
mesh_terms: D019386:Alendronate; D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D001241:Aspirin / Q000494:pharmacology; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D004002:Clodronic Acid / Q000494:pharmacology*; D003907:Dexamethasone / Q000494:pharmacology; D006640:Histidine Decarboxylase / Q000378:metabolism; D007249:Inflammation / Q000139:chemically induced; D007375:Interleukin-1 / Q000172:deficiency / Q000235:genetics; D008297:Male; D051379:Mice; D008807:Mice, Inbred BALB C; D018345:Mice, Knockout; D009929:Organ Size / Q000187:drug effects; D011859:Radiography; D012598:Sclerosis / Q000139:chemically induced; D013154:Spleen / Q000187:drug effects / Q000201:enzymology / Q000473:pathology; D013977:Tibia / Q000000981:diagnostic imaging / Q000187:drug effects / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D050071:Bone Density Conservation Agents; D007375:Interleukin-1; D004002:Clodronic Acid; D003907:Dexamethasone; D006640:Histidine Decarboxylase; D001241:Aspirin; D019386:Alendronate