Changes in cortical bone channels network and osteocyte organization after the use of zoledronic acid.
OBJECTIVE
The aim of this study was to evaluate the effects of zoledronic acid (ZA) on the cortical bone channels network (CBCN) and osteocyte organization in relation to the bone channels.


METHODS
Eighteen male Wistar rats were divided into control (CG) and test groups (TG). Twelve animals from TG received 3 ZA doses (7.5 µg/kg), and 6 animals from CG did not receive any medication. TG animals were euthanized at 14 (n = 6) and 75 (n = 6) dadys after drug injection. CBCN was analyzed in mandibles and tibias using computational routines. The osteocyte organization was qualitatively evaluated in tibias using a three-dimensional reconstruction of images from serial histological sections.


RESULTS
Significant differences in CBCN of tibia were found between the treated and untreated rats, with a wider range of sizes and shapes of the channels after the use of ZA (channels area p = 0.0063, channels area SD p = 0.0276) and less bone matrix (bone volume p = 0.0388). The alterations in the channels' morphology were more evident at 75 days after the drug injection (channels perimeter p = 0.0286). No differences were found in mandibles CBCN. The osteocyte distribution revealed more variable patterns of cell distribution in ZA groups, with non-homogeneous distribution of cells in relation to the bone channels.


CONCLUSIONS
Zoledronic acid induces structural changes in CBCN and modifies the osteocyte arrangement in cortical bone in the tibia; also, the variability in the morphology of bone channels became more evident after a certain time of the use of the drug.
Departamento de Estomatologia, Faculdade de Odontologia, Universidade de São Paulo, São Paulo, SP, Brazil.
Gustavo Davi
GD
Rabelo
Faculdade de Computação, Universidade Federal de Uberlândia, Uberlândia, MG, Brazil.
Bruno Augusto Nassif
BA
Travençolo
Departamento de Estomatologia, Faculdade de Odontologia, Universidade de São Paulo, São Paulo, SP, Brazil.
Marcio Augusto
MA
Oliveira
Instituto de Ciências Biomédicas, UFU, Uberlândia, MG, Brazil.
Marcelo Emílio
ME
Beletti
Departamento de Estomatologia, Faculdade de Odontologia, Universidade de São Paulo, São Paulo, SP, Brazil.
Marina
M
Gallottini
Departamento de Estomatologia, Faculdade de Odontologia, Universidade de São Paulo, São Paulo, SP, Brazil.
Fernando Ricardo Xavier da
FR
Silveira
D000818:Animals; D050071:Bone Density Conservation Agents / Q000494:pharmacology*; D004164:Diphosphonates / Q000494:pharmacology*; D006253:Haversian System / Q000033:anatomy & histology / Q000187:drug effects*; D021621:Imaging, Three-Dimensional; D007093:Imidazoles / Q000494:pharmacology*; D008297:Male; D008334:Mandible / Q000033:anatomy & histology / Q000187:drug effects; D010011:Osteocytes / Q000187:drug effects*; D017208:Rats, Wistar; D018709:Statistics, Nonparametric; D013977:Tibia / Q000033:anatomy & histology / Q000187:drug effects; D000077211:Zoledronic Acid
D050071:Bone Density Conservation Agents; D004164:Diphosphonates; D007093:Imidazoles; D000077211:Zoledronic Acid