Scanning Electron Microscopy of Mechanically Isolated Seminiferous Tubules of the Rat Testis

Abstract

Zusammenfassung Rasterelektronenmikroskopie von mechanisch isolierten Tubuli seminiferi des Rattenhodens Mittels der Rasterelektronenmikroskopie wurden mechanisch isolierte Tubuli seminiferi des Rattenhodens eingehend untersucht. Es wird festgestellt, daß die Oberfläche der Tubuli aus lymphoiden Endothelzellen gebildet wird. Diese Zellen umgeben vollständig die Tubuli seminiferi und bilden das innere Futter des lymphatischen Zwischenraumes, der rundherum um den Tubulus seminiferus liegt. Zwischen den Zellen befinden sich Vertiefungen, die mit den Fenestrierungen korrespondieren, welche man in der Transmissionselektronenmikroskopie sieht.

The cell–cell junctions of mammalian testes. III. Absence of an endothelial cell layer covering the peritubular wall of the seminiferous tubules—an immunocytochemical correction of a 50-year-old error in the literature

“…In the original microscopical studies of testicular tissues, the peritubular wall (PW) cells encasing the seminiferous tubules (STs) have been given a variety of terminological names of which "myoid" has apparently been the mostly used one (for a recent report showing that these cells even represent cells of a novel kind of smooth muscle (SM) tissue, the "lamellar smooth muscle cells" (LSMCs), see Domke and Franke 2019). However, very early on a special exception was introduced and has been repetitively asserted in the literature: the outermost monolayer of very thin and broad cells covering the PW and bordering on the interstitial space has been widely referred to-in particular for rodent testes-as part of a "lymphatic endothelium," i.e., an endothelial cell layer, thus contributing to the formation of a special category of "lymphatic vessels" (e.g., Fawcett et al 1969Fawcett et al , 1970Fawcett et al , 1973Dym and Fawcett 1970;Dym 1975Dym , 1988Dym , 1994Clark 1976;Connell 1976;Wrobel et al 1979Wrobel et al , 1981Söderström 1981;Hadley and Dym 1987;Maekawa et al 1996;Yazama et al 1997;Losinno et al 2012Losinno et al , 2016. To demonstrate the constant reiteration and wide distribution of this concept of a lymphatic endothelial cell layer covering the PW, we present a historical selection list of 15 examples in a Supplementary Literature and Document Collection (SLDC; Online Resource 1).…”