Distribuição de glicoproteinas no ligamento periodontal e no periodonto relacionado ao esmalte do incisivo de camundongo, em diferentes condições funcionais : estudo radioautografico pela incorporação de [3H]-Fucose

AUTOR(ES)

Monica Machado Duarte

DATA DE PUBLICAÇÃO

2004

RESUMO

The periodontal ligament of unimpeded rat incisors show an increase in the amount of non-collagens proteins. To analyse if such increase is related to the higher eruption rate shown by those hipofunctional teeth we visualized through radiautography the uptake of 3H-fucose by periodontal tissues. Female mice were divided in three groups of four animals each. In two of these groups the left mandibular incisor was cut at the level of the gingival papila rendering the tooth hipofunctional while the contralateral incisor became hiperfunctional. In the third group the incisors were kept normofunctional. [3H]-fucose was injected throug the caudal vein: 1) in the first group, 1 day after the shortening of the left incisor; 2) in the second group, 7 days after the left incisor became unimpeded (and so maintained by repeating the shortening every 48h); and 3) in the normofunctional group at same time of the second group. Two animals of each group were killed by intracardiac perfusion of Karnovsky?s fixative at 8 and 96h after injection. The hemimandibules were removed, decalcified, divided in transversal segments and embedded in araldite. 1mm-thick sections of the regions related to the alveolar crest, first lower molar and odontogenic organ were covered with Ilford K-5 nuclear emultion and exposed for 14 days. The area density of silver grains, over periodontal tissues was determined using an image analyzing system. In different degrees of intensity all dental and periodontal tissues were labeled by 3H-fucose. At 8h after the injection the silver grain density was markedly higher in the periodontal ligament related to the alveolar bone and in the enamel related periodontium of incisors kept unimpeded for 7 days as compared with all other groups. These results suggest that the increase of fucosileted glycoproteins (among them fibronectin, integrins and EGF-receptor) in the periodontal tissues of unimpeded incisors is not related to the accelerated rate of the eruption which begins 1 day after their crown is shortened. The uptake of 3H-fucose was conspicuously increased in the perivascular regions of the periodontal tissues and also in the pulp of 7 days hipofunctional incisors, indicating that the higher content of glycoproteins in these tissues may be related to the increase of EGF-receptors

ASSUNTO(S)

proteinas autoradiografia

Documentos Relacionados

• Estudo radioautografico dos efeitos da hidrocortisona no ligamento periodontal de incisivos inferiores de camundongo
• Biossintese de proteinas do ligamento periodontal de incisivos de camundongos em erupção desimpedida e retardada pela vimblastina : estudo radioautografico atraves da incorporação de 3H-glicina
• Efeitos da colchicina, vimblastina e vincristina, no ciclo celular e na velocidade de migração dos ameloblastos ao longo do orgão de esmalte, em incisivos inferiores de camundongo, estudados radioautograficamente, atraves da incorporação de 3H- timidina
• Avaliação estereologica ultraestrutural das densidades volumetricas dos fibroblastos e do colageno do ligamento periodontal do incisivo de rato em condições funcionais alteradas
• Distribuição das fibras de Sharpey no alveolo de incisivo de rato em condições funcionais, normal e alteradas : estudo morfometrico ultraestrutural