RESUMO
The enamel-related periodontium (ERP) in rat incisors is related to bone resorption. In these teeth the face of the socket related to the enamel is continuously removed at the inner side and newly formed at the outer side. CSF-1, RANKL and OPG are regulatory molecules essential for osteoclastogenesis. To verify the effects of impeded eruption on bone remodeling, the tooth eruption was prevented by immobilization of lower rat incisor and CSF-1, RANKL and OPG distribution in the ERP was analyzed after 18 days of immobilization and in normal eruption. The region of the alveolar crest of the rat incisor was used. Immunohistochemistry and tartrate-resistant acid phosphatase (TRAP) were performed. The immunostaining of the dental follicle was quantified using Leica QWin software. Positive-TRAP osteoclasts were counted, and both groups were compared. In the normal incisor, the number of osteoclasts was significantly greater than in the immobilized tooth. In the dental follicle, there was no significant difference in the immunostaining intensity for CSF-1 and OPG between the groups (p > 0.05), but for RANKL the immobilized incisor group showed immunostaining intensity smaller than the normal incisor group (p < 0.01). These findings suggest that changes in the ERP, in the immobilized incisor, modify the RANKL/OPG ratio, in the presence of CSF-1, altering the metabolism of cells that participate in the bone remodeling.
Assuntos
Processo Alveolar/fisiologia , Remodelação Óssea/fisiologia , Esmalte Dentário/citologia , Incisivo/citologia , Fator Estimulador de Colônias de Macrófagos/análise , Osteoprotegerina/análise , Ligamento Periodontal/citologia , Ligante RANK/análise , Fosfatase Ácida/análise , Processo Alveolar/citologia , Ameloblastos/citologia , Animais , Biomarcadores/análise , Matriz Óssea/citologia , Reabsorção Óssea/patologia , Reabsorção Óssea/fisiopatologia , Contagem de Células , Saco Dentário/citologia , Imobilização , Imuno-Histoquímica , Isoenzimas/análise , Masculino , Osteoclastos/fisiologia , Ratos , Ratos Wistar , Fosfatase Ácida Resistente a Tartarato , Erupção Dentária/fisiologia , Alvéolo Dental/citologiaRESUMO
The aim of this study was to analyze the effects of chronic mild unpredictable stress (CMS) on the vasoconstrictor response and morphology of the thoracic aorta and serum lipid profiles in rats. Male Sprague-Dawley rats were submitted to CMS, which consisted of the application of different stressors for 7 days per week across 3 weeks. The rats were sacrificed 15 days after CMS exposure. CMS induced supersensitivity to the vasoconstrictor effect of phenylephrine in endothelium-intact thoracic aortic rings without changes in aortic rings without endothelium, or pre-incubated with nitric oxide (NO) synthesis inhibitor. Rats submitted to CMS showed hypertrophy of the intima and tunica media of thoracic aorta, increased serum levels of triglycerides, total cholesterol, very low-density lipoprotein cholesterol, low-density lipoprotein cholesterol and atherogenic index, without changes in high-density lipoprotein cholesterol levels, when compared with control rats. These data indicate that CMS induces physiological and morphological changes that may contribute to the development of atherosclerosis by mechanisms related to deficiency in NO production and dyslipidemia.