title: S 12911-2 inhibits osteoclastic bone resorption in vitro.
abstract: The potential anti-osteoporotic activity of the strontium compound, S12911, was tested on osteoclast-like cells and on cultured fetal mouse long bones. From 1 mM Sr2+, S12911 reduced both basal and stimulated bone resorption by decreasing osteoclast activity and ruffled border formation. The aim of this study was to evaluate the effects of S 12911-2 on osteoclastic bone resorption using in vitro systems. Osteoclast-like cells, produced in vitro by co-culture of mouse bone marrow cells with primary osteoblasts, were allowed to settle on dentine slices, and the area of resorption pits formed after 48 h was measured using an image analysis system. S 12911-2, at a minimal active concentration of 1 mM Sr2+, significantly reduced pit formation by these cells (p < 0.05). Pretreatment of slices for 48 h with S 12911-2 (5 mM Sr2+) did not produce appreciable inhibition of resorption. Bone resorption in cultured fetal mouse long bones was assessed by measuring the release of pre-incorporated 45calcium. S 12911-2 inhibited resorption in control cultures (18.9%, p < or = 0.05) and in bones cultured with the active form of vitamin D3 [1,25(OH)2D3] (44.5%, p < or = 0.05). S 12911-2 had no effect on the number of osteoclasts observed histochemically in longitudinal sections prepared from fetal mouse long bones. Electron microscopy of mouse long bones treated with S 12911-2 (3 mM Sr2+) showed osteoclasts with clear zones facing the bone surface, but without well-developed ruffled borders; untreated bones contained osteoclasts with normal ruffled borders. These results indicate that S 12911-2 inhibits osteoclast activity. This effect is directly linked to the presence of strontium, is effective on basal and stimulated resorption, and involves a decrease in ruffled border formation by osteoclasts.
authors.affiliation: Department of Biochemistry, School of Dentistry, Showa University, Tokyo, Japan.
authors.forename: N
authors.initials: N
authors.lastname: Takahashi
authors.forename: T
authors.initials: T
authors.lastname: Sasaki
authors.forename: Y
authors.initials: Y
authors.lastname: Tsouderos
authors.forename: T
authors.initials: T
authors.lastname: Suda
mesh_terms: D000818:Animals; D000831:Animals, Newborn; D001862:Bone Resorption / Q000517:prevention & control*; D018929:Cell Culture Techniques; D002478:Cells, Cultured; D051379:Mice; D008815:Mice, Inbred Strains; D009924:Organ Culture Techniques; D009942:Organometallic Compounds / Q000494:pharmacology*; D010010:Osteoclasts / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D010012:Osteogenesis; D010024:Osteoporosis / Q000517:prevention & control*; D013876:Thiophenes / Q000494:pharmacology*
chemical_list: D009942:Organometallic Compounds; D013876:Thiophenes; C081587:strontium ranelate