Light and electron microscopic study on the oxytalan elaunin and elastic fibers in the inferior segment of the human esophagus.

A light and electron microscopic study on oxytalan, elaunin and elastic fibers was performed in the inferior segment of the human esophagus of 30 individuals aged, from 2 months to 76 years. Paraffin sections were stained by the aldehyde-fuchsin (Gomori 1950), Orcein (Unna-Tanzer 1891), resorcinol-fuchsin (Weigert 1898) and iron-hematoxylin (Verhoeff 1908), with or without a previous oxidation by peracetic acid. For the electron microscope, the fixation was performed in a 3% glutaraldehyde solution with 0.25% of tanic acid in Millonig buffer (Futaesaku et al. 1972; Cotta-Pereira et al. 1975, 1976). A subepithelial network of oxytalan fibers (fibrotubular bundles) without direct connections with the BM and indirectly related to this one through periodical reticulin like fibers, were described. More deeply the oxytalan fibers are in continuity with elaunin and these with elastic fibers, close to the LMM. The TSs and the TA are essentially formed by elastic fibers and by relatively scanty presence of elaunin ones. From the TM and probably from the LMM, among the muscle cells, oxytalan fibers gradually change to elaunin and these to elastic fibers toward the connective tissue septa situated among muscle bundles and connective layers (LPM, TSm and TA (or TSs). A fibrilar (fibrotubular) "continuum" is here admitted, extending from the TA to the subepithelial BM with a variable amount of elastin like material, according to the layer they belong. They change progressively from oxytalan to elastic fibers, passing through an intermediate phase of elaunin fibers.