The Maceration Technique in Scanning Electron Microscopy of Collagen Fiber Frameworks: Its Application in the Study of Human Livers.

Abstract

Summary. This paper reviews the cell-maceration/ scanning electron microscopic (SEM) technique and its application in the study of human livers. The maceration of glutaraldehyde-fixed tissues with 2N-NaOH and water at room temperature effectively and consistently removes all the cells, thus exposing collagen fiber networks. SEM of the macerated tissues shows threedimensional arrangements of collagen fibers more clearly than previously reported methods. High resolution SEM observations of macerated and non-macerated collagen fibrils of the rat tail tendon have revealed that both show similar cross-striated bandings that are determined by an alternate succession of elevated and depressed segments along the collagen fibrils, with a period of approximately 65nm. Three ridges have been observed in the nonmacerated collagen fibrils: two on the margins of the elevated segments and one at an intermediate point of the depressed segment. The macerated collagen fibrils show a straight arrangement with slightly wavy microfibrils.The subendothelial spaces of Disse in the human liver contain abundant collagen fibers. There are some collagen fibers that stretch between adjacent collagen fiber sheaths in the subendothelial spaces of Disse, either forming a mono-layered network or coursing individually. The collagen fibers in the spaces of Disse are continuous with those in the liver capsule and in the Glisson's sheaths and with those around the central and sublobular veins. The collagen fibers in human livers form a network of the liver as a whole, thus constituting a hepatoskeletal system.

Implicit mechanistic role of the collagen, smooth muscle, and elastic tissue components in strengthening the air and blood capillaries of the avian lung

“…Within physiological limits, at all lung volumes, collagen limits lung expansion while elastin brings about its recoil (Mead, 1961;Senior et al 1975). The alveoli of the mammalian lung have a dedicated collagen cable that tracks the 'supporting side' of interalveolar septum (Weibel, 1973(Weibel, , 1984, forming a connective tissue scaffold that constitutes part of the 'fibroskeleton' of the lung (Wang & Ying, 1977;Gil & Martinez-Hernandez, 1984;Matsuda et al 1987;Amenta et al 1988;Mercer & Crapo, 1990, 1992Mercer et al 1994;Ohtani & Nakatani, 1994; Schematic illustration of the components of the collagen fiber system in the parabronchus of the lung of the domestic fowl shown in longitudinal, transverse, and three-dimensional views. From the inside out, the internal (axial ⁄ central) column mainly consists of the collagen fibers that occur in the rims of the atria (A); the interatrial septal collagen band (B) is intercalated between the collagen fibers that form the rims of the atria (A) and those that form the interinfundibular band (C).…”

“…Tissues samples measuring about 2 · 3 · 5 mm were taken from the lung and digested to remove all tissue components except collagen according to the methods described by Ohtani (1987Ohtani ( , 1992 and Tochima et al (2004). Briefly, the tissues were placed in a 10 M solution of sodium hydroxide (NaOH) for 4 days at room temperature (20°C).…”

3-D Ultrastructural Distribution of Collagen in Human Placental Villi at Term in Relation to Vascular Tree

“…In order to investigate the fine collagen microarchitecture and 3-D distribution of various chorionic villi at term as well as their relationship with vascular tree, two different digestion techniques, using sodium hydroxide 2N and 6N [18], were applied in this study followed by SEM.…”

“…The 2N NaOH method allows to study by SEM the 3-D organization of the collagen network housed in the extracellular space after selective digestion of all tissue and cell components but collagen, as previously successfully revealed in numerous organs, including pancreas [19], liver [18,20], cardiac tissue [21], lymphoid follicles [22], uterus [23], human umbilical cord [24] and placenta [25]. The 6N NaOH method, by removing connective tissues, allows to study by SEM 3-D the cellular distribution [26,27], mainly represented by vessels and trophoblast.…”

Estudo da mucosa da língua e da superficie de interface epitélio-tecido conjuntivo da preguiça-de-coleira (Bradypus torquatus, Iliger, 1811), empregando os métodos de microscopia de luz e eletrônica de varredura

“…Destacou dois tipos de papilas foliadas: caudal, localizada na mesma posição das papilas valadas de diversos mamíferos, com criptas ântero-posteriores e; lateral, com fendas verticais. Silva (1999), através de estudo de microscopia de luz, microscopia eletrônica de varredura, encontrou os quatro tipos básicos de papilas na língua de coelho (Oryctolagus cuniculus) e descreveu suas formas, distribuição e analisou os constituintes da lâmina própria de tecido conjuntivo por meio de maceração celular em solução de NaOH, que se trata de aperfeiçoamento na digestão da camada epitelial para expor o tecido conjuntivo em aspectos originais, técnica preconizada por Ohtani (1987Ohtani ( , 1992. Este mesmo tratamento de maceração da camada epitelial foi utilizado por Martinez et al (2000) para visualizar a arquitetura do tecido conjuntivo na língua da chinchila (Chinchilla laniger) onde foi estudada a estrutura tridimensional das papilas linguais por meio da microscopia eletrônica de varredura.…”