Evaluation of protein undernourishment on the condylar process of the Wistar rat mandible correlation with insulin receptor expression

The mandible condylar process cartilage (CP) of Wistar rats is a secondary cartilage and acts as a mandibular growth site. This phenomenon depends on adequate proteins intake and hormone actions, including insulin. Objectives The present study evaluated the morphological aspects and the expression of the insulin receptor (IR) in the cartilage of the condylar process (CP) of rats subjected to protein undernourishment. Material and Methods The nourished group received a 20% casein diet, while the undernourished group (U) received a 5% casein diet. The re-nourished groups, R and RR, were used to assess the effects of re-nutrition during puberty and adulthood, respectively. CPs were processed and stained with picro-sirius red, safranin-O and azocarmine. Scanning electron microscopy and immunohistochemistry were also performed. Results The area of the CP cartilage and the number of cells in the chondroblastic layer decreased in the U group, as did the thickness of the CP layer in the joint and hypertrophic layer. Renourishment during the pubertal stage, but not during the adult phase, restored these parameters. The cell number was restored when re-nutrition occurred in the pubertal stage, but not in the adult phase. The extracellular matrix also decreased in the U group, but was restored by re-nutrition during the pubertal stage and further increased in the adult phase. IR expression was observed in all CPs, being higher in the chondroblastic and hypertrophic cartilage layers. The lowest expression was found in the U and RR groups. Conclusions Protein malnutrition altered the cellularity, the area, and the fibrous cartilage complex, as well as the expression of the IRs. .

Estudos dos efeitos de um anti-inflamatório não esteroidal seletivo para COX-2 na osteogênese e na expressão das proteínas COX-2 e RUNX-2 durante o reparo ósseo alveolar em ratos / Effect of a selective anti-infflamatory inhibitor of COX-3 in the osteogenesis and COX-2 and RUNX-2 proteins expression in the alveolar bone healing in rats

Objetivo: No atual trabalho propomo-nos a avaliar morfometricamente possíveis alterações na reparação óssea alveolar pós-exodontia de ratos tratados com Meloxicam, um anti-inflamatório inibidor preferencial da cicloxigenase 2 (COX-2) e correlacionar com a expressão temporal da COX-2 e do fator de transcrição 2 com domínio Runt (Runx-2) associada com a diferenciação de células da linhagem osteoblástica. Material e Métodos: A exodontia do incisivo superior direito foi realizada em 120 ratos Wistar, divididos em grupo controle (n = 60) - animais tratados com injeção intraperitoneal de 0,1 ml de solução salina 0,9% diariamente e grupo tratado (n = 60) animais tratados com injeção de Meloxicam na dose de 3mg/kg de massa corporal, diariamente, ambos durante 7 dias. O volume total do alvéolo (VtA) e do tecido ósseo (VtO), o número de células imunomarcadas/mm² (Nm) para COX-2 e Runx-2 e a expressão protéica por Western blotting (WB) da COX-2 e RUNX-2 foram avaliados nos períodos 3, 7, 10, 14, 21 e 30 dias póscirurgias. Resultados: No grupo tratado o VtA manteve-se constante até os 21 dias, enquanto que no controle foi 0,272 vezes menor em relação aos 3 dias decorrente da maior atividade osteoclástica. Porém, aos 14 dias, no grupo tratado o VtO foi 0,337 vezes menor em relação ao controle decorrente da inibição parcial da transmigração de células inflamatórias responsáveis pela degradação do coágulo e da angiogênese, ocasionando um retardo na formação dos tecidos de granulação/conjuntivo, na diferenciação das células osteoblásticas e na formação/remodelação do tecido ósseo, e consequentemente no reparo ósseo alveolar. A imunomarcação para COX-2 foi observada em diversos tipos celulares, como fibroblastos, células endoteliais, células inflamatórias, osteoblastos e osteócitos. O Nm para COX-2 não apresentou diferenças estatísticas significantes entre os grupos no intervalo de 3 e 21 dias pós-cirurgia, enquanto que, a expressão...

Objective: To evaluate morphometrically possible changes in post-extraction alveolar bone healing in rats treated with Meloxicam, a selective anti-inflammatory inhibitor of cyclooxygenase (COX-2) and to correlate it with the temporal expression of COX-2 and transcription factor 2 with Runt domain (Runx-2) associated with differentiation of osteoblastic lineage cells. Material and Methods: The extraction of the right upper incisor was made in 120 male Wistar rats, divided into control group (n=60) - animals treated with an intraperitoneal injection of 0,1 ml of 0,9% NaCl solution daily for 7 days and the treated group (n=60) - animals treated with injection of 3mg/kg of body weight of Meloxicam 0.9% NaCl solution daily for 7 days. The total alveolar volume (VtA), total bone tissue volume (VtO), number of immunohistochemically positive cells/mm² (Nm) for COX-2 and RUNX-2 and the Western blotting (WB) COX-2 and RUNX-2 protein expressions were evaluated after 3, 7, 10, 14, 21 and 30 days after the surgeries. Results: In the treated group the VtA remained constant until the 21st day, while in the control group at the same day the value was 0,272 times lower compared to the 3 days period, due to the higher osteoclastic activity. However, at 14 days the VtO was 0,337 times lower in the treated group compared to the control due to the partial inhibition of the transmigration of inflammatory cells responsible for the degradation of the clot and angiogenesis, causing a delay in the formation of granulation/connective tissues, differentiation of osteoblastic cells and in bone tissue formation/remodeling, and consequently in the alveolar bone repair. The immunostaining for COX-2 was observed in various cell types, such as fibroblasts, endothelial cells, inflammatory cells, osteoblasts and osteocytes. The Nm for COX-2 showed no statistical differences between groups from the 3rd to the 21st day, while the WB protein expression was on average 0,232 times lower in the...