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

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 three-dimensional 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 65 nm. 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.