Mineralizing process and morphological structure of the femoral bone in rats under influence of aminophosphonates
Semen O. Mostovoy, Viktor F. Shulgin, Elena M. Maksimova, Igor A. Nauhatsky, Elena T. Melucova, Kristina A. Plehanova.
Objective: The degree of crystallinity and peculiarities of morphological structure changes in external and internal surface of femoral bone proximal epiphyses in rats under influence of the aminobiphosphonate drug pamidronate or the non-opioid branded equivalent tweak (aminophosphonate substance) was evaluated.
Methods: Thirty Wistar rats were used in the research and 3 groups of animals (1 control and 2 experimental, n = 10 in each group) were formed. The control group of animals received 1 ml of deionized water intragastrically (i.g.) and 1 ml of normal saline intraperitoneally (i.p.) once a day for 3 months. The experimental rats received administration of pamidronate i.p. or tweak i.g. (63 mg/kg for both) for 3 months. The external and internal surfaces of femoral bone proximal epiphyses were studied with scanning electron microscopy. The degree of crystallinity of the mineral parts of samples was estimated with X-ray crystal structure analysis.
Results: Animals that received pamidronate presented high mineralization of collagen matrix; the growth plate became narrower, the size of foramina nutricia and the branches of Volkmanns canals became smaller. X-ray diffraction (XRD) patterns showed increased interplanar distance compared to XRD patterns of the control group. Animals that received tweak had the highest degree of mineralization and visual breaking of the growth plate; the size of foramina nutricia and the number of branches of Volkmanns canals decreased. Dispersity of mineral component took place on XRD patterns as flattening of peaks in regions of small angles.
Conclusion: Administration of pamidronate or tweak for 3 months caused bone hypermineralization and changed the parameters of elementary lattice cell that lead to structural disorders of femoral proximal epiphyses in rats.
Key words: Aminobisphosphonate; Aminosphosphonate; Growth plate; Metamphetamine; Phosphonate; Tweak