Modelo experimental para o estudo de fibras de colágeno no músculo esquelético

PURPOSE: To examine histological and histomorphometric techniques for measuring collagen in skeletal muscle. METHODS: The following staining methods were used in the study: hematoxylin and eosin, Masson's trichrome, reticulin, and picrosirius red, and immunostaining for collagen types I, II, III, IV, and V. Histomorphometric measurements were performed using Corel PhotoPaint and UTHSCSA Image Tool 3.0 software. RESULTS: Both the Masson's trichrome and picrosirius red staining provided the best visualization for the measurement of collagen content. CONCLUSION: This methodology is important for the identification and quantification of the different types of collagen in muscles and can be used in the investigation of the qualitative and quantitative influence of collagen on physical activities, aging, and diseases.OBJETIVO: Examinar os procedimentos empregados na quantificação do colágeno por métodos histológicos e histomorfométricos. MÉTODOS: Foram utilizadas colorações histológicas por HE, Tricrômico de Masson, Reticulina, Picrossírius e reação imuno-histoquímica para colágeno I, II, III, IV e V. A quantificação histomorfométrica foi realizada utilizando-se os programas Corel PhotoPaint e Image Tool versão 3.0. RESULTADOS: Os métodos histológicos de Masson e Picrossírius apresentaram uma maior facilidade na quantificação do colágeno. CONCLUSÃO: Este modelo é importante para que possa ser identificado e quantificado os diferentes tipos de colágenos nos músculos e relacionar com a atividade física, envelhecimento e doenças.UNIFESPUNIFESPSciEL

Immunohistochemical analysis of collagen content and types in the rectus abdominis muscle of cadavers of different ages Imunohistoquímica do colágeno no músculo reto do abdome de cadáveres de diferentes grupos etários

PURPOSE: To assess the collagen content and types in the rectus abdominis muscle of cadavers of different ages. METHODS: Forty fresh adult male cadavers, at room temperature, were obtained from the Institute of Legal Medicine of Franca and dissected within 24 hours of death. The cadavers were divided into two groups: Group A (n=20), 18 to 30 years of age, and Group B (n=20), 31 to 60 years of age. Bilateral incisions were made in the middle portion of anterior rectus sheath 3 cm superiorly and 2 cm inferiorly to the umbilicus and four fragments of the rectus abdominis muscle were dissected. The samples were fixed in 10% buffered formalin and sent for immunohistochemical analysis to determine collagen content and types. RESULTS: Immunohistochemical results revealed higher amounts of type I and type III collagen in Group A. However, no difference in the amount of type IV collagen was found between the groups. CONCLUSION: The amount of type I and type III collagen was higher in group A.<br>OBJETIVO: Avaliar o colágeno no músculo reto do abdome em cadáveres de diferentes faixas etárias. MÉTODOS: Foram dissecados 40 cadáveres adultos masculinos, não fixados, com tempo de óbito de até 24 horas, em temperatura ambiente, provenientes do Instituto Médico-Legal de Franca (SP - Brasil). Os cadáveres foram distribuídos em dois grupos: GRUPO A (n=20) - 18 a 30 anos e GRUPO B (n=20) -31 a 60 anos. Realizou-se incisão na porção mediana da lâmina anterior da bainha do músculo reto a 3 cm superiormente e 2 cm inferiormente ao umbigo em ambos os lados, sendo retirados quatro fragmentos de músculo reto do abdome. Esse material foi conservado em formalina tamponado a 10% e enviado para imuno-histoquímica para determinação do tipo de colágeno. RESULTADOS: Na Imunihistoquímica os colágenos I e III foram estatisticamente maiores no grupo A, porém não houve diferença entre os grupos em relação ao colágeno IV. CONCLUSÃO: A quantidade de colágeno tipo I e III foi maior no grupo A

Collagen fibers in the rectus abdominis muscle of cadavers of different age

To assess collagen content and types in the rectus abdominis muscle of cadavers of different ages.Forty fresh adult male cadavers within 24 h of death were obtained from an Institute of Legal Medicine and divided by age at death into Group 1 (mean age, 23.3 years; range, 18-30 years; n = 20) and Group 2 (mean age, 46.2 years; range, 31-60 years; n = 20). From each cadaver, samples of the rectus abdominis muscle measuring 1 cm(2) were collected 3 cm superiorly and 2 cm inferiorly to the umbilicus. Histological sections were prepared and stained with picrosirius red and Masson's trichrome stain for visualization of total collagen fibers, and immunohistochemical analysis was performed to distinguish types I, II, III, IV and V collagen.No significant differences in total collagen were found between groups by Masson's trichrome staining. However, picrosirius red staining revealed a significantly greater amount and higher concentration of total collagen and types I and III collagen in Group 1 than in Group 2 (P < 0.05). All but type II collagen were detected by immunohistochemistry in both groups. No significant difference in type IV collagen was found between groups. Type V collagen was detected by immunohistochemistry in both groups, but quantification was not possible due to background staining.The amounts of types I and III collagen in the rectus abdominis muscle were significantly smaller in older subjects.Universidade Federal de São Paulo UNIFESP, Div Plast Surg, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Pathol, BR-04023062 São Paulo, BrazilUniv Santo Amaro UNISA, Dept Biostat, São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Div Plast Surg, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo UNIFESP, Dept Pathol, BR-04023062 São Paulo, BrazilWeb of Scienc