Modulação da atividade osteoclástica in vitro mediada por diferentes doses do hormônio da paratireóide

• Autor(a) principal: Mota Filho, Haroldo Gurgel
• Data de Publicação: 2016
• Tipo de documento: Trabalho de conclusão de curso
• Idioma: por
• Título da fonte: Repositório Institucional da UFRN
• Texto Completo: https://repositorio.ufrn.br/handle/123456789/39204
• topic: Hormônio Paratireóideo; Osteoclasto; Remodelação óssea

Bone remodeling is a process regulated by the interaction between cells and various molecules such as parathyroid hormone (PTH). The objective of the study was evaluate the effect of different doses of PTH on osteoclast activity in a culture model of bone organs. Male C57BL/6 mice (n=14), six-day old, were subbmited to euthanasia to obtain the calvaria, which were dissected and seccionated in the middle, keeping the periosteal and endosteal. The bone fragments were divided three groups: Group I (control - without adding PTH), Group II (addition of 3 nM PTH) and Group III (30 nM PTH), all cultured in αMEM for up to 72 hours. The osteoclast activity was evaluated by biochemical quantification of calcium released in the culture medium at intervals of 24, 48, and 72 hours and by histomorphometric analysis of bone resorption lacunae at 72 hours. Our results show that group II exhibited significantly higher values of calcium levels in the medium compared to group I (p <0.05) in all intervals, being also higher for the group III at 24 hours (p < 0.05). Bone resorption lacunae in group II were more extensive (average 4900 μm2/gap) and promoted greater demineralization area (average 22052 μm2/field) than those found in group I (average 1042 μm2/gap and 2084 μm2/field) and group III (average 1492 μm2/gap and 8952 μm2/field). We concluded that PTH osteoclast activity in vitro is dose-dependent and promotes higher bone resorption when administered in low doses.