Distribuição do colágeno tipo I, colágeno tipo III e versican na lâmina própria da prega vocal humana de fetos e adultos: método histoquímico e imunoistoquímico / Collagen type I, collagen type III and versican distribution within the lamina propria of fetal and adult human vocal fold : histochemical and immunohistochemical method

AUTOR(ES)
DATA DE PUBLICAÇÃO

2008

RESUMO

Extracellular matrix has an important rule in the vocal fold physiology and the knowledge about your components is necessary. Fewer studies about matrix extracellular and no studies about versican in fetuses, and the necessity to improve the knowledge about extracellular matrix components in adults group came us to the elaboration of this study that has the objective to analyze the presence and distribution of collagen type I, type III and versican in human vocal fold lamina propria of fetal and adult larynges. Seven fetal larynges obtained from 28- to 36- week-old cadaveric fetuses were studied. Twenty larynges were obtained from adults (10 males and 10 females). Mean age of males was 66 and 70 from females, without significant statistical difference between groups. For the analysis of versican expression, immunohistochemical reactions were carried out in fetal and adult group. The larynges were analyzed through Picrosirius polarization method and immunohistochemistry to visualize the collagen fibers, in fetal and adult group respectively. Collagen fibers and proteoglycan were quantified using a digital image analysis system. In fetuses, the collagen fibers system exhibited homogeneous distribution pattern in a monolaminar layer and spatial arrangement as in a wicker basket; predominance of versican distribution was found out on the superficial and intermediate layer of vocal fold lamina propria. In adult group, there was a lower collagen type I density in the intermediate layer when compared to the superficial (p<0.001) and the deep layers (p=0.005). Collagen type III presented a lower density in the intermediate layer when compared to the deep layer (p=0.001) but without differences in the superficial layer. There was a lower versican density in the superficial layer when compared to the intermediate layer (p=0.036) and deep layer (p=0.013). There was a lower versican density in the lamina propria of females when compared with males. The difference was noted in the superficial layer only. When all layers are considered together there was a positive correlation between versican and collagen type III densities (r=0.57; p=0.010). This study shows the differences in the extracellular matrix components distribution in lamina propria vocal folds in fetal and adult group permitting a discussion about the implications in vocal fold physiology and suggesting that laryngeal structures will be prepared to vocalization at birth

ASSUNTO(S)

imunoistoquímica immunohistochemistry vocal cords versican colágeno tipo i colágeno tipo iii versicans collagen type iii collagen type i larynx cordas vocais laringe

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