Elastic tissue in the limiting membrane of the human seminiferous tubule

Abstract

The structure and distribution of elastic tissue were studied in the limiting membrane of the seminiferous tubule from normal human testis. The elastic and elastic-related fibers (oxytalan and elaunin) were recognized by their tinctorial and ultrastructural characteristics. The connective structures of the limiting membrane, including the fibrotubules and the amorphous material of the elastic system, were studied after tannic acid-glutaraldehyde fixation. Fibrotubules (oxytalan fibers) were observed in almost all intercellular spaces of the limiting membrane, closely related to the contractile cells; the elaunin fibers (patches of amorphous material surrounded by bundles of fibrotubules) were evident in the outermost layers. The function of this system of elastic tissue and myoid cells is discussed, considering the permeability membrane and the role of the myoid cells in the elastogenesis and contractility of the seminiferous tubule.

Endothelial layers in fish skin

“…In Ciliata mustela [ Fig. 4(d)] the fibrous zone, which contains electron-dense filaments interspersed among paler amorphous material, resembles the elastic tissue in the arterial wall of salmonids (Serafini-Fracassini et al, 1978) and elastic tissue in mammals (Leak & Burke, 1966Menezes, 1977). No protein with the amino acid composition of elastin exists in the aortae of cyclostomes (Sage & Gray, 1977) but this does not imply that cyclostomes lack tissues with elastic properties; the distribution of the fibrotubules in lamprey skin suggests that they contribute to such a tissue.…”

“…Some material of species of Barbus, Corydoras and Blennius was fixed in 2.5% or 3O/ o glutaraldehyde with the addition of 0.25% tannic acid (Menezes, 1977) and some in 5% glutaraldehyde with ethylene-diamine-tetraacetic acid (EDTA) as used by Lanzing & Wright ( I 974). Embedding and sectioning were by standard methods; sections were stained with uranyl acetate and lead citrate and examined in AEI 6B and Corinth 275 electron microscopes.…”

“…During the course of this investigation we have used material from the species listed below, which are arranged in systematic order, following Greenwood et al (1 966) for orders and families ofteleosts and Wheeler (1969) (Menezes, 1977) and some in 5% glutaraldehyde with ethylene-diamine-tetraacetic acid (EDTA) as used by Lanzing & Wright ( I 974). Embedding and sectioning were by standard methods; sections were stained with uranyl acetate and lead citrate and examined in AEI 6B and Corinth 275 electron microscopes.…”

“…In Corydoras paleatus and Blennius pholis where the fibrous zone, although present, was not conspicuous in electron micrographs, nothing could be distinguished after Verhoeffs stain. The tannic acid method, supposed to demonstrate elastic tissue (Menezes, 1977), proved unreliable; there were signs of tissue damage, unequal penetration, staining of collagen, and some electron-dense elements were also found in the control preparations. In lamprey skin, Verhoeff s iron haematoxylin distinguished the cellular elements, including the dermal endothelium, from the pink dermal collagen, but it was not possible to make out the fibrous zone as such; blue-grey threads crossed the dermis vertically, and may have represented the vertical bundles of fibrotubules.…”

Die Lamina propria der Hodenkanälchen von Wirbeltieren: Eine vergleichende licht- und elektronenmikroskopische Untersuchung: The lamina propria of vertebrate seminiferous tubules: A comparative light and electron microscopic investigation

“…This consists of myofibroblasts (Bock et al -1972), fibroblasts, collagen fibers, ground substance and a basal lamina on which spermatogenic and Sertoli cells rest (Clermont -1958;Burgos et al -1970). The lamina propria is also reported to contain elastic fibers (De Menezes -1977). The lamina propria and its cells form the morphological basis for the peristaltic movements of the seminiferous tubules discovered by Roosen-Runge in 1951.…”