Estudo do reparo ósseo com matriz óssea bovina desvitalizada e calcitonina em ratos

Abstract

OBJETIVO: Estudar o efeito da calcitonina no reparo de defeito femoral preenchido com matriz óssea bovina desvitalizada. MÉTODOS: Quarenta e oito ratos Wistar, machos e adultos foram distribuídos aleatoriamente em dois grupo com 24 animais. Defeitos femorais bilaterais, com 2mm de diâmetro, foram produzidos na diáfise femoral e preenchidos com matriz óssea bovina desvitalizada. O grupo experimento recebeu 0,05mL de calcitonina, intramuscular, no pós-operatório imediato; o grupo controle recebeu 0,05mL de cloreto de sódio 0,9%. Os animais foram sacrificados com 7, 14 e 21 dias e os fêmures submetidos a avaliação clínica, microscópica e histométrica. Foram utilizados os testes "t" de Student, Kruskal-Wallis e Mann-Whitney para a análise estatística dos resultados. RESULTADOS: Os resultados clínicos não mostraram diferença entre os grupos controle e experimento. Microscopicamente, os defeitos mostraram reação inflamatória e formação óssea ativa nas proximidades da matriz óssea bovina. A análise quantitativa mostrou maior formação óssea nas fases iniciais da osteogênese reparadora no grupo experimento (Z=4,82 e Z=4,43), sem diferenças em relação à reação inflamatória em ambos grupos. CONCLUSÃO: O uso de calcitonina em defeitos preenchidos com matriz óssea bovina desvitalizada estimula a neoformação óssea com 7 e 14 dias de pós-operatório, mas não diminui a reação inflamatória.

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“…When is used drugs with capacity of reducing the osteoclastic action, the tendency it is that the process of bony deposition is increased, for the osteoblastic action, because both cells participate actively of the formation process and dynamic re-absorption of the bone. Such aspect was observed by Sassioto et al 5 , in accomplished study using the same experimental model used in this work. For its anti-inflammatory, analgesic and osteoclastic inhibitory properties, the calcitonina is used in the treatment of diseases characterized by excessive bony remodelation, as the menopause osteoporosis, Paget' disease and malign hypercalcaemia.…”

“…Several factors can influence in a positive or negative way the organization and result end of the process of bone repair. Some of them posses influence that can only be investigated in experimental studies 4,5 . The factors that can influence positive or negatively the reparative osteogenesis composes the objective of several experimental studies and they should be analyzed by different angles, because many of these aspects are put upon, and this perspective is crucial to its understanding 6 .…”

“…Studies demonstrate the delayer effect of nonsteroidal anti-inflammatory drugs in the repair and bony remodelation; the daily use of sodic diclofenac harms the bony repair, taking to the instability of the bony callus; the meloxicam increases the neutrofil's flow with decrease of osteoclast; and the tenoxican presents important inhibitory effect on the osteogenesis 8 . Other drugs same tends antiinflammatory, they seem to stimulate the osteogenesis, as it is the case of the calcitonin, a polypeptide composed for 32 amino acids secreted by the C cells of the thyroid, that acts directly on the osteoclasts, inhibiting the bony reabsorption and promoting analgesic action for decrease of the local synthesis of prostaglandins 5,9 . The calcitonina participates actively of the skeletal homeostasis as regulator of the mineral and bony metabolism, interfering in the action of the parathyroid hormone in the maintenance of the bony mass.…”

“…The main factor related to the hypocalcaemia of the calcitonin effect is its union to the osteoclastic cells, causing morphologic and chemotaxis alterations and reducing them to cells mononucleares. The connection of the calcitonina to the osteoclasts is followed by elevation of the intracellular level of cAMP and calcium, suggesting that these act as messengers of the calcitonin action, which also reduces the necessary enzymatic processes to the bony reabsorption 5,9 . When is used drugs with capacity of reducing the osteoclastic action, the tendency it is that the process of bony deposition is increased, for the osteoblastic action, because both cells participate actively of the formation process and dynamic re-absorption of the bone.…”

“…The animal experimentation and the clinical studies showed that the salmon's calcitonin is the more it activates up to now of the isolated calcitonins and absolutely it exempts of exogenous animal proteins. In spite of the evidence of the anti-osteoclastic action of the calcitonina, the anabolic function of that hormone is still controversial, mainly in relation to the fibroblasts and/or osteoblasts 5,9 . Considering to be the bony repair a cellular function of osteoclast and osteoblast cells, involved directly in the bony mineral metabolism, with direct regulation for the calcitonin, a hormone broadly used in the treatment of diseases related with the bony formation alterations and affected for several drugs used for pain control, we took place a experimental study standardized with the purpose of observing the use of anti-inflammatory drugs associated to the calcitonin would promote incentive of the osteogenesis without delay of the analgesic and antiinflammatory function, in rats.…”