Winrich Breipohl

Microridge Cells in the Larynx of the Male White Rat. Investigations by Reflection Scanning Electron Microscopy

SummaryThe laryngeal epithelium of male white rats is studied by reflection scanning electron microscopy (SEM). In addition to ciliated cells, microvilli cells, brush cells and goblet cells that are characteristic for normal respiratory epithelium the microridge or labyrinth cell can be seen in particular regions of the larynx.The apical surface of a typical labyrinth cell is characterized by a system of narrow standing microridges of about 0.05–0.15 μm in diameter and interconnecting microridges with a diameter of about 0.01 μm.The microridge system of a labyrinth cell originates from the fusion of densely standing microvilli. Between microridge cells and microvilli cells all transition forms can be observed. The preferable localiziation of the microridge cell in the larynx and its possible function is discussed.ZusammenfassungDas Kehlkopfepithel ausgewachsener männlicher Albinoratten wird rasterelektronenmikroskopisch untersucht. Zusätzlich zu den zilientragenden und zu den Mikrovillizellen, zu den Bürsten- und Becherzellen, welche insgesamt für das respiratorische Epithel charakteristisch sind, werden in bestimmten Abschnitten des Larynx die Mikroleisten- oder Labyrinthzellen beschrieben. Die freie Oberfläche typischer Labyrinthzellen ist durch ein System von sich verzweigenden Mikroleisten gekennzeichnet, die miteinander durch Querbrücken verbunden sind und in der Zellperipherie eine bevorzugte Parallelausrichtung zur Zellgrenze zeigen können. Der Durchmesser der Mikroleisten beträgt ca. 0,05–0,15 μm. Die Querverbindungen zwischen den Mikroleisten haben einen Durchmesser von ca. 0,01 μm. Der Raum zwischen zwei benachbarten Querbrücken variiert. Labyrinthzellen können außer Mikroleisten auch Mikrovilli zeigen und es gibt Übergänge zwischen den Mikroridge- und den Mikrovillizellen.Die bevorzugte Lokalisation der Mikroleistenzellen im Bereich der Glottis und des Aditus laryngis wird belegt. Die mögliche Funktion dieser Zellen und ihre Bedeutung für die Diagnostik pathologischer Schleimhautveränderungen wird diskutiert.

The Effect of N-Methyl-Formimino-Methylester on the Neural Olfactory Threshold in Albino Mice*

SummaryThe effects of N-methyl-formimino-methylester were studied in albino mice. Very short exposure (0.5 and 1 s) to the concentrated vapour led to an increase of the neural olfactory threshold to geraniol by a factor of 105–107. There was a slow recovery of the olfactory sensitivity and after about 40 days the threshold values returned to normal.

Die Oberflächenmorphologie des Trachealepithels männlicher Albinoratten

The epithelial surface of trachea in adult male albino rats is studied by reflection scanning electron microscopy (REM). Surface morphology of the tracheal epithelium shows extensive individual and regional variability. Identical surface morphology may result by different causal factors. Regional morphology is presented by a mapping of the epithelial surface. Special attention is given to the structure of the cilia. Furthermore the morphology and distribution of possible receptor cell terminals is shown. The validity of reflection scanning electron microscopic studies for identifying the patho-histogenetic action of air pollutants is discussed.SummaryThe epithelial surface of trachea in adult male albino rats is studied by reflection scanning electron microscopy (REM).Surface morphology of the tracheal epithelium shows extensive individual and regional variability. Identical surface morphology may result by different causal factors.Regional morphology is presented by a mapping of the epithelial surface. Special attention is given to the structure of the cilia. Furthermore the morphology and distribution of possible receptor cell terminals is shown.The validity of reflection scanning electron microscopic studies for identifying the pathohistogenetic action of air pollutants is discussed.

Rasterelektronenmikroskopische Studien am Epithel der Plica vocalis von männlichen Albinoratten

SummaryThe epithelial surface of the Plica vocalis in adult male rat is studied by scanning electron microscopy.Its structure is compared with that of the plica and of the recessus ventricularis. The transition of the epithelium in the plica vocalis to the epithelium of the joining parts of the larynx is documented. Special attention is paid to the occurrence of microridges at the apical poles of epithelial cells in the larynx. Up to now microridge cells have been said to be characteristic for the plica vocalis.ZusammenfassungDas Stimmbandepithel ausgewachsener männlicher Albinoratten wird rasterelektronenmikroskopisch untersucht. Seine Oberflächenstruktur wird mit jener des Epithels auf der Plica ventricularis und im Recessus ventricularis verglichen. Charakteristischerweise zeigen die Zellen im Epithel über den Stimmbändern einen dichten, lückenlosen Besatz mit Mikrovilli. Die Übergänge des Stimmbandepithels in die benachbarten Larynxabschnitte wird dokumentiert. Besondere Aufmerksamkeit wird dem Auftreten von Mikroleisten auf den apikalen Zellpolen im Larynxepithel gewidmet, die bisher als charakteristische Struktur für das Stimmbandepithel gewertet wurden.

Light microscopical investigations (Chemical blockade of olfactory perception by N-methylformimino-methylester in albino mice ; 2)

Evidence is given that N-methyl-formimino-methylester (MFM), a highly volatile substance, causes olfactory receptor cell degeneration in mice. The time course of this degeneration and morphological changes in the compartment of receptor cell progenitor cells are described. Due to the morphological appearance of the progenitor cells and their dynamic transformation after exposure to MFM, two different types of progenitor cells can be distinguished: (a) light-staining globose basal or blastema cells, which are thought to be real progenitor cells and to remain in the mitotic cycle for generating new sensory cells; and (b) dark-staining basal cells with condensed chromatin, which are quiescent. The results agree with electrophysiological data indicating temporary inhibition of olfactory perception after MFM.

Untersuchungen und Befunde

Zu Einzelheiten der angewandten Methoden wird auf die Einzelveroffentlichungen verwiesen (siehe Literaturanhang).

Rasterelektronenmikroskopische Studien zur Feinstruktur des Epiglottisepithels von Ratten

SummaryThe epithelial surface of the epiglottis in adult male and female albino rats is studied by scanning electron microscopy.Prominent differences exist between the surface morphology as observed in the males and that observed in the females sacrificed in the estrus phase of the ovarial cycle. The differences are most pronounced in respect to the amount of secretory vesicles, microvilli- and microridge-cells and in respect to the observable number of desquamating cells.The existence and the importance of the microridge-cells are discussed. Special attention is also paid to the results indicating that at least some parts of the extrapulmonary airway epithelia act as possible target organs for sex hormones.Finally the importance of the observed differences is discussed for the correct interpretation of pathomorphological alterations in the extrapulmonary airway epithelia that have been observed under experimental conditions and during infections.