Avaliação do sinal insulínico em ratos adultos com lesão periapical
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Data
2013-03-08
Autores
Astolphi, Rafael Dias [UNESP]
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Editor
Universidade Estadual Paulista (Unesp)
Resumo
Patologias na cavidade oral podem gerar efeitos deletérios em diversos sistemas do organismo. Nesse sentido, a presença de bactérias nas polpas dentárias pode provocar lesão periapical (LP) e gerar inflamação, culminando na produção de citocinas inflamatórias, como o fator de necrose tumoral-alfa (TNF-α) e a interleucina-6 (IL-6), que podem atingir a circulação sistêmica e causar a resistência insulínica (IR) em órgãos responsivos à insulina. A IR é definida como a diminuição da resposta de tecidos periféricos à ação da insulina, e indivíduos com esta característica são predispostos a desenvolver diabetes mellitus tipo 2 (DM2). Tendo conhecimento de que as citocinas inflamatórias podem gerar alteração no sinal insulínico (SI), tornou-se primordial investigar a possibilidade de um processo inflamatório local, como a LP “per se”, causar IR em indivíduos não diabéticos. Para tanto, foram utilizados ratos Wistar (02 meses de idade), divididos em dois grupos: ratos com LP induzida em primeiro molar superior direito, empregando-se broca em aço carbono dotada de esfera na extremidade com 0,1 mm de diâmetro e ratos-controle (CN). Após 30 dias de indução, realizaram-se os experimentos: 1) coleta de sangue (n=10) e obtenção de plasma para análise das concentrações de glicose, insulina, colesterol total, colesterol HDL (HDL-C), colesterol LDL (LDL-C), colesterol VLDL (VLDL-C), triglicérides, TNF-α e interleucina-6 (IL-6); 2) teste de tolerância à insulina (ITT) para a avaliação da sensibilidade à insulina (n=10); 3) avaliação do grau de fosforilação em tirosina da pp185 (IRS-1/IRS-2) e dos conteúdos de receptor insulínico beta (Rβ) e de substrato do receptor insulínico-1 (IRS-1) em tecido adiposo branco periepididimal, muscular...
Oral cavity’s pathologies may cause deleterious effects in different body systems. The presence of bacteria in dental pulp may cause periapical lesion (PL) and generate inflammation, culminating in the production of inflammatory cytokines including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). These cytokines can reach the systemic circulation and may cause insulin resistance (IR) in insulin-responsive tissues. IR is defined as a decreased response of peripheral tissues to insulin action, and individuals with this metabolic state are predisposed to develop type 2 diabetes mellitus (T2DM). Knowing that the inflammatory cytokines may generate alterations in insulin signal, it becomes essential to investigate the possibility of a local inflammatory process as the PL per se cause insulin resistance in non- diabetic individuals. Therefore, the purpose of this study was to determine whether PL can cause changes in the initial phase of insulin signaling and in insulin sensitivity in non-diabetic rats. For this purpose, Wistar rats (two-month-old) were used in the present study. The animals were divided into two groups: 1) group with induced PL in right first upper molars by using a dental handpiece (spot size 0.1 mm); 2) control group (CN). After 30 days post induction, experiments were carried out: 1) blood collection (n = 10) obtaining plasma for glucose, insulin, total cholesterol, HDL cholesterol (HDL-C), triglycerides, LDL cholesterol (LDL-C), VLDL cholesterol (VLDL-C), TNF-α and IL-6 analyses; 2) insulin tolerance test (ITT) for evaluating insulin sensitivity (n = 10); 3) assessment of pp185 (IRS-1 / IRS-2) tyrosine phosphorylation and insulin receptor-beta (Rβ) and insulin receptor substrate-1 (IRS-1) content in periepididymal... (Complete abstract click electronic access below)
Oral cavity’s pathologies may cause deleterious effects in different body systems. The presence of bacteria in dental pulp may cause periapical lesion (PL) and generate inflammation, culminating in the production of inflammatory cytokines including tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6). These cytokines can reach the systemic circulation and may cause insulin resistance (IR) in insulin-responsive tissues. IR is defined as a decreased response of peripheral tissues to insulin action, and individuals with this metabolic state are predisposed to develop type 2 diabetes mellitus (T2DM). Knowing that the inflammatory cytokines may generate alterations in insulin signal, it becomes essential to investigate the possibility of a local inflammatory process as the PL per se cause insulin resistance in non- diabetic individuals. Therefore, the purpose of this study was to determine whether PL can cause changes in the initial phase of insulin signaling and in insulin sensitivity in non-diabetic rats. For this purpose, Wistar rats (two-month-old) were used in the present study. The animals were divided into two groups: 1) group with induced PL in right first upper molars by using a dental handpiece (spot size 0.1 mm); 2) control group (CN). After 30 days post induction, experiments were carried out: 1) blood collection (n = 10) obtaining plasma for glucose, insulin, total cholesterol, HDL cholesterol (HDL-C), triglycerides, LDL cholesterol (LDL-C), VLDL cholesterol (VLDL-C), TNF-α and IL-6 analyses; 2) insulin tolerance test (ITT) for evaluating insulin sensitivity (n = 10); 3) assessment of pp185 (IRS-1 / IRS-2) tyrosine phosphorylation and insulin receptor-beta (Rβ) and insulin receptor substrate-1 (IRS-1) content in periepididymal... (Complete abstract click electronic access below)
Descrição
Palavras-chave
Doenças periapicais, Resistência à insulina, Inflamação, Proteínas substratos do receptor de insulina, Rato, Diabetes Mellitus Tipo 2, Periapical diseases
Como citar
ASTOLPHI, Rafael Dias. Avaliação do sinal insulínico em ratos adultos com lesão periapical. 2013. 94 f. Dissertação (mestrado) - Universidade Estadual Paulista Júlio de Mesquita Filho, Faculdade de Odontologia de Araçatuba, 2013.