Zonulae occludentes im Pansenepithel der Ziege

Zusammenfassung Das Pansenepithel besitzt in den tiefen Hornzellen, die an das Stratum granulosum grenzen, eine Barriere. Diese Barriere, die das Labyrinth der Interzellularräume gegen das Pansenlumen verschließt, ist mit Zonulae occludentes ausgestattet.

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Zonulae occludentes in the goat ruminal epithelium

Summary The deep horn cells of the goat ruminal epithelium, which border the stratum granulosum, form an important component of the epithelial barrier. This barrier of the intercellular labyrinth presents zonulae occludentes (tight junctions).

Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Untersuchungen zur Feinstruktur und Histochemie der Glandula bulbourethralis der Ziege

Zusammenfassung Die Mehrzahl der sezernierenden Zylinderzellen in den tubulösen Endstücken der Glandula bulbourethralis der Ziege sind Schleimzellen. Ihre großen, aufgehellten Sekretgranula, die fast den gesamten Zelleib ausfällen, liegen so dicht, daß sie sich gegenseitig abplatten. Einzelne von ihnen haben ihre Hüllmembran verloren und neigen zur Konfluenz. Alle Schleimkörnchen sind PAS-positiv, viele von ihnen zeigen eine neuraminidaselabile Alcianophilie bei pH 2,5. Neben den Schleimzellen findet man in der Glandula bulbourethralis der Ziege einen zweiten Zelltyp, der durch helle, blasenförmige Kerne, ein stark entfaltetes granuläres endoplasmatisches Retikulum mit dilatierten Zisternen sowie ein ausgedehntes supranukleares Golgi-Feld gekennzeichnet ist. Dieser zweite Zelltyp enthält sehr elektronendichte, isoliert liegende Sekretkugeln, welche lichtmikroskopisch eine Proteinreaktion geben. Zwischen beiden Zelltypen kommen morphologische Übergangsformen vor. Dies macht es wahrscheinlich, daß es sich bei den beiden Typen lediglich um Funktionsstadien einer einzigen Drüsenzelle handelt. Die sezernierende Oberfläche beider Zelltypen ist durch die Ausbildung interzellulärer Sekretkapillaren vergrößert. Diese sind bereits lichtmikroskopisch aufgrund ihrer kräftigen ATPase- und 5-Nucleotidaseaktivität zu identifizieren. Das gesamte Drüsenparenchym reagiert sehr stark auf unspezifische Esterase und deutlich positiv auf -D-Galactosidase, -D-Glucuronidase, Leucinaminopeptidase, Cytochromoxydase und Succinatdehydrogenase. Die letzten 5 Enzyme sind in den Schleimzellen in geringerer Konzentration festzustellen als in den Zellen mit Eiweißgranula.

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Studies on the ultrastructure and histochemistry of the bulbourethral gland in the goat

Summary The majority of the secretory cells in the tubular endpieces of the caprine bulbourethral gland are mucous cells. Their closely packed, relatively large secretory granules exhibit a low electron density. Some granules have lost their limiting membrane, this results in the accumulation of irregularly outlined masses of secretory material. All mucous secretory granules are PAS-positive, many of them are characterized by an alcianophilia at pH 2.5 which is extinguished by pre-treatment with a neuraminidase solution. The second type of secretory bulbourethral cell exhibits light, spherical nuclei, a well developed rough endoplasmic reticulum with dilated cisterns and a large supranuclear Golgi-Complex. The cytoplasm contains smaller, highly electron dense granules which are — according to histochemical tests — of protein nature. The existence of transitional forms between both described cell types permits the conclusion that they must be regarded as functional stages of one common gland cell. The secretory surface of both cell types is increased by intercellular canaliculi which can be identified in the light microscope by their strong ATPase and 5-nucleotidase activities. The entire parenchyma of the gland is site of an exceptionally high esterase concentration. Furthermore, the gland cells contain considerable amounts of -D-galactosidase, -D-glucuronidase, leucine aminopeptidase, cytochrome oxydase and succinic dehydrogenase. These last five enzymes are histochemically more active in the protein secreting than in the mucus producing cell type.

Mit dankenswerter Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Tight junctions and cavitation in the human pre-embryo.

In the human morula, tight junctions are found between all cell pairs, at all levels of cellular apposition, associated with underlying masses of microfilaments. In cavitating morula, lanthanum tracer gained access to the intracellular spaces, except at the intersections with nascent extracellular cavities, marking the first assembly of zonulae occludentes. Presumptive trophectoderm cells contained vacuoles and larger cavities often associated with secondary lysosome-like bodies. Since the vacuoles and intracellular and extracellular cavities contain electron-dense polygranules of about 23 nm diameter, they may have common origins. In trophectoderm cells of the early blastocytes, the large intracellular vacuoles and cavities were absent, and the zonulae occludentes were located apically. Mechanisms for nascent blastocoele formation are discussed.     

Cell junctions in the epithelium of Bowman's capsule

Summary The intercellular connections between the epithelial cells of Bowman's capsule were investigated. It could be demonstrated that typical zonulae occludentes (tight junctions) are present in the species (rat, hamster, and Tupaia) studied. Freeze-fracturing shows a network of anastomizing strands; some species variations are described. In the rat two strands are common. In the golden hamster mostly two to four and occasionally five strands occur. In Tupaia regularly three tight junction strands are found and also gap junctions associated with the zonulae occludentes. In thin sections the goniometric analysis confirms the freeze-fracturing results and reveals attachment zones of macular shape, which are classified as intermediate junctions and desmosomes. The functional role of these cell junctions observed in the epithelium of Bowman's capsule is discussed.     

Structure of zonulae occludentes and the permeability of the epithelium to short-chain fatty acids in the proximal and the distal colon of guinea pig

Summary Absorption of short-chain fatty acids has been studied in the proximal and the distal colon of anaesthetized guinea pigs. Segments were perfused with a solution similar in chemical composition to that of normal colonic fluids. In the proximal colon the permeability of the mucosa was similar for acetate, propionate and butyrate. For acetate the permeability was significantly higher in the proximal than in the distal colon, and the reverse was seen for butyrate. In the distal colon the short-chain fatty acids seem to be absorbed mainly in the undissociated form due to their lipid solubility: a paracellular pathway for the dissociated molecules is of no major importance. In the proximal colon, on the other hand, a considerable portion of acetate and propionate disappears in the ionized form. Light microscopy (semithin sections) and electron microscopy (freeze-fracture replicas) showed remarkable morphological differences between the proximal and the distal colon. Leaky spots with only few strands were present in the zonulae occludentes between the epithelial cells at the surface of the proximal colon. In the distal colon the junctions between the cells were more compact, and significantly more strands separated the lumen from the intercellular space. These results suggest that short-chain fatty acids could be absorbed by a paracellular pathway in the proximal colon, and not in the distal colon. In the proximal colon the number of strands of the zonulae occludentes between surface cells and that between cryptal cells was similar. On the contrary, in the distal colon significantly more strands were present between surface cells than between cryptal cells. Morphological and physiological considerations suggest that absorption of short-chain fatty acids in the crypts is negligible.     

Histochemische und elektronenoptische Untersuchungen über Adenosintriphosphatasen des endometrialen Oberflächenund Drüsenepithels der Ziege (Capra hircus)

Zusammenfassung Im Oberflächen- und Drüsenepithel des nicht graviden Uterus der Ziege wurden licht- und elektronenoptische Untersuchungen über den Nachweis der Mg⁺⁺-, Ca⁺⁺- und der (Mg⁺⁺-Na⁺-K⁺)-aktivierbaren ATPasen durchgeführt.Spezifische Enzymaktivitäten lassen sich nur an Proben aus der Follikelphase nachweisen. In der Corpus luteum-Phase dagegen liegen diese Enzyme nicht in nachweisbarer Intensität vor.Die lichtmikroskopisch an den seitlichen Zellflächen nachgewiesenen Niederschläge der ATPasen finden sich elektronenoptisch als schwarze Granula an der Außenlamelle der lateralen Plasmalemm-Abschnitte. An apikalen und basalen Zellmembran-Bereichen in beiden Zyklusphasen zu beobachtende Reaktionsprodukte sind das Ergebnis einer Spontanhydrolyse des Substrats ATP bzw. von Spaltungen aufgrund der unspezifischen alkalischen Phosphatase. Haftkomplexe und Desmosomen sind regelmäßig frei von Bleisalz-Niederschlägen. Es können weder regionale Unterschiede in der Reaktionsintensität der Enzyme noch Differenzen im Hinblick auf die Verteilung und ultrastrukturelle Lokalisation von Niederschlägen der Mg⁺⁺-bzw. der Ca⁺⁺-aktivierbaren ATPase festgestellt werden.

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Histochemical and electron microscopic studies of the adenosine triphosphatases in the endometrial surface and glandular epithelium of the goat (Capra hircus)

Summary Light and electron microscopic studies were performed on the Mg⁺⁺-, Ca⁺⁺-, and the (Mg⁺⁺-Na⁺-K⁺)-activated ATPases in the surface and glandular epithelium of the non-pregnant uterus of the goat.Specific enzyme activities have been shown only in the epithelial samples collected during the follicular phase. In the luteal phase, none of these enzymes have been demonstrated with certainty. Precipitates of the ATPases which have been shown with the light microscope on the sides of the cell surface, can electron optically be observed as black granules on the outer lamella of the lateral plasmalemma. Reaction products on the apical and basal cell membrane regions observable in both cyclic phases, result from spontaneous hydrolysis of the substrate ATP, i.e. splitting caused by non-specific alkaline phosphatase. Junctional complexes and desmosomes are regularly free from lead salt precipitates. Neither regional differences in reaction intensity of the enzymes nor differences in the distribution and ultrastructural localization of either Mg⁺⁺-or Ca⁺⁺-activated ATPase precipitates can be observed.

Frau E. Merl danken wir für sorgfältige technische Mitarbeit.     

Cytochemische Untersuchungen über die alkalische Phosphatase im Vormagenepithel der Ziege

Zusammenfassung Mit licht- und elektronenmikroskopischen Methoden wurde die Verteilung und Aktivität der unspezifischen alkalischen Phosphatase im Epithel der drei Vormägen der Ziege untersucht und gleichzeitig der Einfluß verschiedener Fixiermittel und unterschiedlicher Vorfixierungs- und Inkubationszeiten auf das Ergebnis der Enzymreaktion geprüft. Es wurde festgestellt, daß die alkalische Phosphatase bei allen untersuchten Proben nur im Stratum corneum, Stratum granulosum und Stratum spinosum superf. vorkommt. Verschiedene Vorfixierungen der Proben entweder mit Formol-Kalzium (24 Std) oder Glutaraldehyd (2, 5, 30, 120 min) bzw. OsO₄ (2 oder 5 min) beeinflussen die Enzymverteilung und Reaktionsstärke nicht. Beim lichtmikroskopischen Nachweis wurde die maximale Reaktionsstärke bereits bei einer Inkubationszeit von 10 min bei Zimmertemperatur erreicht. Für den elektronenmikroskopischen Enzymnachweis war eine Inkubationszeit von 5 min bei 4° C am günstigsten. Die Reaktionsprodukte sind sowohl an den Zellmembranen als auch in Zellpartikeln lokalisiert. Die zellmembrangebundenen Reaktionsprodukte befinden sich bei allen mit Glutaraldehyd vorfixierten Proben an der äußeren Lamelle, bei kurzzeitiger Osmiumvorfixation (3 min) hingegen an der Innenseite der Plasmamembranen.

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Cytochemical study of alkaline phosphatase activity in the goat forestomach epithelium

Summary Light and electron microscopic techniques were employed to study the distribution and intensity of the non-specific alkaline phosphatase activity in the epithelium of the three forestomachs of the goat. The effects on the enzyme reaction of different fixatives, prefixatives, and incubation times were determined.Alkaline phosphatase was found to be present only in the stratum corneum, stratum granulosum, and stratum spinosum superf. of each of the specimens. Different prefixation of the specimens, either by formol calcium (24 h), glutaraldehyde (2, 5, 30, 120 min), or osmium tetroxide (2 or 5 min) had no influence on the distribution of the enzyme and the intensity of its reaction. Maximal intensity of the reaction was obtained after an incubation period of 10 min at room temperature, as seen with the light microscope. To demonstrate the enzyme in sections in the electron microscope, an incubation period of 5 min at 4° C was found to be optimal. The products of the enzyme reaction were located on cell membranes and in cell particles. The membrane-bound reaction products in the specimens prefixed with glutaraldehyde were found on the outer surface of the plasma membrane; after a short prefixation with osmium tetroxide (3 min), they appeared on the inner surface of the plasma membrane.

Auszugsweise vorgetragen auf dem Kongreß der Europäischen Vereinigung der Veterinäranatomen vom 8.–10. September 1969 in Parma.     

Fibrillar and cytoskeletal substructure of tight junctions: Analysis of single-stranded tight junctions linking fibroblasts of the lamina fusca in hamster eyes

Summary The lamina fusca of the hamster eye contains layers of flattened, slightly overlapping fibroblasts. Thin sections of the overlapping margins reveal punctate, tight-junction-like membrane appositions associated with accumulation of cytoplasmic filaments, 5–7 nm in diameter. Intermediate filaments are present in the surrounding cytoplasm. A diffuse dense substance occurs in adjacent intercellular space. Freeze-fracture replicas show that the membrane appositions are mainly single-stranded tight junctions, each composed of two fibrils (micelles), and each continuous or nearly continuous around the fibroblastic perimeter. Fracturing characteristics of these junctions offer a unique opportunity to gain further insight into tight junctional morphology. When exposed, the fibrils adhere to the P-face, measure 9.2±0.3 nm in diameter, and are accompanied by a narrow band of membrane differing in texture from non-junctional membrane. Characteristically, the junctional fibrils themselves mark the deviation line along which fracture planes pass from one membrane of the junction to the other. This pattern exposes, over long distances, the P-face of one membrane on one side of this line and E-face of the adjacent membrane on the other. Analysis of any single junction over such distances reveals that the juxtaposition of the fibrils may gradually twist or undulate over a range of at least 180° within the two involved membranes. The fracture plane appears preferentially to pass between the two junctional fibrils; association of the cytoskeleton with junctional fibrils may govern this route of fracture. Cytoskeletal attachment appears to be to a single fibril and may alternate from one fibroblast to the next depending on which cytoplasmic leaflet is nearest a given fibril.Parts of this work have been presented at meetings of the Association for Research in Vision and Ophthalmology (Kelly and Hageman 1983) and the American Association of Anatomists (Hageman and Kelly 1984)     

Histochemische,elektronenmikroskopische und biochemische Untersuchungen über die ATPasen im Vormagenepithel der Ziege

Zusammenfassung Am Epithel der drei Vormägen der Ziege wurden licht- und elektronenmikroskopische Untersuchungen über den Nachweis der Mg⁺⁺-, (Mg⁺⁺-Na⁺-K⁺)- und der Ca⁺⁺-aktivierbaren ATPasen durchgeführt. Bereits an lichtmikroskopischen Präparaten wurde festgestellt, daß sich deutliche Unterschiede in der Enzymaktivität der Mg⁺⁺- und Ca⁺⁺ stimulierbaren ATPasen sowohl für die einzelnen Epithelschichten als auch für die verschiedenen Bereiche der Vormägen nachweisen lassen; die tiefen Epithellagen reagieren stets stärker als die oberflächlichen. Ferner ist die in hohem Maße von der Inkubationszeit abhängige Reaktionsstärke im Epithel des Blättermagens größer als in der Lamina epithelialis des Netzmagens und vor allem in jener des Pansens. Bei dem elektronenmikroskopisch geführten Nachweis der ATPasen zeigt sich, daß die Reaktionsprodukte an der Außenseite der Zellmembranen liegen. Frei von Niederschlägen sind alle Zellmembranabschnitte, die sich an der Bildung der Desmosomen und Halbdesmosomen beteiligen sowie die basalen Abschnitte der Basalzellen.Im Hinblick auf die Verteilung und feinstrukturelle Lokalisation konnten keine Unterschiede zwischen den Mg⁺⁺-, Ca⁺⁺- und (Mg⁺⁺-Na⁺-K⁺)-aktivierbaren ATPasen beobachtet werden.In Anlehnung an die Methode nach Coleman u.a. (1967) wurden Zellmembranen von Pansenepithelzellen isoliert und an diesen biochemische Enzymbestimmungen durchgeführt. Die Ausbeute der gewonnenen Zellmembranen betrug, gemessen anhand der 5-Nukleotidase, dem Leitenzym für Plasmamembranen, gegenüber dem eingesetzten Gesamthomogenat 0,3%. Die mit diesem Verfahren durchgeführten biochemischen Enzymbestimmungen erbrachten den Nachweis, daß in den Plasmamembranen der Pansenepithelzellen neben der Mg⁺⁺- und Ca⁺⁺-aktivierbaren auch eine (Na⁺-K⁺)-abhängige Transport-ATPase vorkommt.

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Histochemical, ultrastructural and biochemical studies of atpases of the goat forestomach epithelium

Summary Light- and electron microscopical studies were carried out to demonstrate ATPases activated by Mg⁺⁺, by (Mg⁺⁺-Na⁺-K⁺), and by Ca⁺⁺. Histological sections showed clear differences of the activity of Mg⁺⁺- and Ca⁺⁺-stimulated ATPases in the light microscope in different layers of the epithelium as well as in different areas of the forestomach. The deeper layers reacted more intensely than the superficial ones. The intensity of the reaction (which depends on incubation time) in the omasal epithelium was stronger than in the lamina epithelialis of the reticulum and much stronger than in the lamina epithelialis of the rumen. In the electron microscope, the reaction products of the ATPase appeared on the outer surface of cell membranes (plasmalemmata). No deposits of the reaction products were observed on those areas of the cell membranes, which are involved in the formation of desmosomes and semidesmosomes. The basal parts of the basal cells were also free from reaction products. As for the distribution and ultrastructural localisation of the deposits, no differences were observed among the ATPase stimulated by Mg⁺⁺, (Mg⁺⁺-Na⁺-K⁺), and Ca⁺⁺.Using the technique of Coleman et al. (1967), the cell membranes of ruminal epithelium were isolated. Biochemical assays of the enzymes were carried out. The quantity of cell membranes obtained was 0.3% of the whole homogenate, when compared with 5-nucleotidase, which is the typical enzyme of plasmalemmata. The biochemical enzyme assays showed that, besides Mg⁺⁺- and Ca⁺⁺-dependent ATPases, a (Na⁺-K⁺)-dependent transport ATPase exists in the cell membranes of ruminal epithelial cells.

Die cytochemischen Ergebnisse wurden auszugsweise auf dem Kongreß der Europäischen Vereinigung der Veterinäranatomen vom 9.–11. September 1968 in Belgrad vorgetragen.     

Intercellular junctions in the water-blood barrier of the gill lamella in the adult lamprey (Geotria australis,Lampetra fluviatilis)

Thin sections and freeze-fracture replicas of the water-blood barrier in the gill lamellae of adult lampreys (Geotria australis, Lampetra fluviatilis) demonstrate that the occluding junctions between epithelial pavement cells differ markedly from those between endothelial pillar cells in the structure and arrangement of their strands. The zonulae occludentes between pavement cells typically consist of complex networks of 4–6 strands, the mean number of which undergoes a small but significant decline when the animal is acclimated to seawater. In comparison, the occluding junctions between pillar cells are less elaborate and may represent maculae or fasciae, rather than zonulae occludentes. They do not apparently undergo a change when the animal enters saltwater. The results indicate that the main part of the paracellular diffusion barrier to proteins and ions is located in the epithelium rather than the endothelium. Communicating (gap) junctions are present between adjacent pavement cells, between pavement and basal cells and between pillar cells. These findings suggest that the epithelial cells and the pillar cells in the water-blood barrier of lampreys both form functional syncytia. The results are discussed in the context of ion-transporting epithelia in other aquatic vertebrates.This paper is dedicated to Professor H. Leonhardt on the occasion of his 75^th birthday     

Saure und alkalische Phosphatase sowie Adenosintriphosphatasen im Epithel der Pars proventricularis des Pferdemagens

Zusammenfassung Im Epithel der Pars proventricularis des Pferdes wurden mit licht- und elektronenmikroskopischen cytochemischen Methoden eine lysosomale saure Phosphatase sowie die Mg⁺⁺- und Ca⁺⁺-aktivierbaren ATPasen nachgewiesen und lokalisiert. Positive Reaktionen der unspezifischen alkalischen Phosphatase fanden sich dagegen ausschließlich an den subepithelialen Gefäßschlingen der Papillae occultae.Die ATPasen-Aktivität nimmt vom Stratum basale zum Stratum superficiale kontinuierlich ab. Die Reaktionsintensität ist nach 45 min-Inkubationszeit optimal und läßt sich nicht weiter steigern. Eine Erhöhung der Mg⁺⁺-aktivierbaren Grundaktivität des Enzyms durch Na⁺ und K⁺ ist cytochemisch nicht nachweisbar. Die Reaktionsprodukte haften an der äußeren Lamelle der Zellmembranen. Frei von Enzymaktivitäten sind lediglich die an der Bildung von Desmosomen und Halbdesmosomen beteiligten Plasmalemm-Abschnitte.Einige Probleme des aktiven Transportes, die sich aus den histochemischen Enzym-Befunden ergeben, werden diskutiert.

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Histochemical and ultrastructural study of the acid phosphatase, alkaline phosphatase, and adenosine triphosphatase contents in the pars proventricularis epithelium of the horse stomach

Summary The activities and localization of a lysosomal acid phosphatase and of a Mg⁺⁺-and Ca⁺⁺-activated ATPase were shown in the pars proventricularis epithelium of the horse stomach using cytochemical methods and the light and electron microscopes. Activity of the non-specific alkaline phosphatase was exclusively demonstrated on the subepithelial vessel loops of the papillae occultae.The activity of ATPases gradually decreased from the stratum basale to the stratum superficiale. Reaction intensity was optimal after 45 min and did not increase further. An increase of the Mg⁺⁺-activated basal activity by Na⁺ and K⁺⁺ was not shown cytochemically. Reaction products adhered to the outer lamellae of plasmalemmata. Only the plasmalemmal regions forming desmosomes and hemidesmosomes were free of enzyme activities.Some problems of active transport related to activities of these enzymes have been discussed.

Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Effect of disodium fumarate on ruminal metabolism and rumen bacterial communities as revealed by denaturing gradient gel electrophoresis analysis of 16S ribosomal DNA

The aim of the present study was to examine the effects of feeding diets with addition of disodium fumarate (DF) to goats on ruminal metabolism and changes of rumen bacterial communities. Four cannulated goats were used in a 4 × 4 Latin square design. The results showed that ruminal pH increased linearly (P<0.01)as the amount of DF added increased, while lactate production decreased linearly (P<0.01). DF addition did not affect the production of acetate, propionate, butyrate, TVFA and NH₃-N. The effect of DF on the changes in rumen bacterial-community structure of goats was analyzed using 16S rDNA-based approaches. Amplicons of the V6-V8 variable regions of bacterial 16S rDNA were analyzed by denaturing gradient gel electrophoresis (DGGE), cloning and sequencing. Differences in rumen bacterial community structure were determined based on the Shannon index of diversity for pairwise comparison of the DGGE fingerprints and revealed significant changes in rumen microbiota after DF addition. As compared with those fed with the control diet, goats fed on the diets with DF addition showed a higher bacterial diversity. The sequences of seven amplicons in total 11 clones showed less than 97% similarity with those of previously identified or unidentified bacteria, suggesting that most bacteria in the gastrointestinal tract have not been cultured or identified. Amplicons related to Succinivibrio dextrinosolvens species were found in most DGGE fingerprints derived from goats on the diet containing DF, but not in goats on the control diet. These results demonstrated the ability of DF to improve the metabolism of rumen lactate fermentation and to influence the bacterial composition of the rumen in goats.     

Entstehung und Ultrastruktur der Biondi-Körper in den Plexus chorioidei des Menschen (Biopsiematerial)

Zusammenfassung Bei 50–60jährigen Menschen enthält das Plexusepithel Einschlüsse (Biondi-Körper), die als Zeichen einer Alterung gelten. Elektronenmikroskopisch bestehen sie aus einer fibrillären Komponente und verschiedenartigen tropfigen (Lipid) oder granulären (u.a. Lipofuszin) Strukturen. Nach Frühstadien solcher Komplexe wurde im Seitenventrikel-plexus (Biopsiematerial) 20–30 Jahre alter Personen gefahndet. In dieser Altersgruppe haben wir nur Lipidtropfen, Lysosomen, stark osmiophile Partikel und Konglomerate dieser Einschlüsse beobachtet; die für ältere Menschen charakteristischen Filamentbündel (Fasern) ließen sich bisher nicht nachweisen. Das Plexusepithel einer 54jährigen Frau war reich an verschiedenen Entwicklungsstadien fibrillärer Biondi-Strukturen. Aus 80–100 Å starken Filamenten bestehende Bündel können frei im Grundplasma der Plexuszelle liegen; ähnliche Filamente trifft man auch innerhalb von großen lysosomenartigen Körpern an. Solchen Fasern bzw. Lysosomenkomplexen lagern sich Lipidtropfen, kleinere elektronendichte Cytosomen und Lipofuszingranula an. Einzelne Filamente sind quergestreift, mit einer Periode von etwa 40–50 Å und globulären Untereinheiten (Durchmesser etwa 25 Å). Nach Färbung mit Kongorot sind die Biondi-Fasern stark doppelbrechend; ein Teil dieses Materials leuchtet grün, andere Faserstrukturen zeigen einen gelben Farbton. Diese Merkmale entsprechen den Strukturcharakteristika von Amyloidfasern. Auf den Amyloidcharakter der Biondi-Einschlüsse haben bereits Divry (1955) und Schwartz (1970) hingewiesen; immunbiologische Aspekte ihrer Entstehung sind zu diskutieren. Einzelne Biondi-Einschlüsse können auch in den Liquor cerebrospinalis austreten. Gebilde, die an die nichtfibrilläre Komponente der Biondi-Körper erinnern, wurden auch im Endothel und in den Pericyten der Plexusgefäße dargestellt.

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Formation and ultrastructure of Biondi bodies in the human choroid plexus (biopsy material)

Summary The choroid epithelium of 50–60-year old persons contains inclusions known as Biondi bodies. These inclusions have been presumed to be signs of aging. Electron microscopic studies have shown that mature Biondi bodies contain filaments, various droplets, and dense granular structures. The vesicular inclusions are identified as lipid droplets; lipofuscin pigment may be associated with lysosomes. In the present studies, in order to analyse the early stages of formation of Biondi bodies, we investigated biopsy material from 20–30-year old persons. In this age group, we observed lipid bodies, lysosomes, osmiophilic particles, and complexes of these structures, but not the filament bundles that were characteristically present in older persons. In a 54-year-old female, the choroid epithelium contained different forms and stages of Biondi fibers. Some groups of filaments of 80–100 Å mean diameter were seen in cytoplasm; others were located in large lysosome-like bodies. Both types of inclusions were associated with lipid droplets, small electron-dense cytosomes and lipofuscin pigment granules. Some filaments showed cross-striation with about 40–50 Å periodicity and globular subunits measuring about 25 Å in diameter. In sections stained with Congo red, the Biondi fibers were strongly birefringent and displayed green or yellow colors. These data are in agreement with the morphological and physical characteristics of human amyloid fibrils and filaments. It has been suggested by Divry (1955) and Schwartz (1970) that Biondi bodies contain amyloid deposits. Immunobiological aspects should therefore be considered in relation to the formation of Biondi bodies. Evidence has been found in our material that single Biondi bodies may be extruded into the cerebrospinal fluid. Further, structures resembling the vesicular and granular components of Biondi bodies were observed in the endothelium and pericytes of the choroid vessels.

Mit Unterstützung durch die Deutsche Forschungsgemeinschaft.     

Cell junctions in the renal tubule of a fresh-water teleost,Salmo gairdneri Rich.

Summary Cell junctions in the renal tubule of the fresh-water rainbow trout were studied with thin-section and freeze-fracture techniques. Gap junctions were restricted to the proximal tubule, which is consistent with other vertebrate classes. Segments I and II of the proximal tubule and the collecting tubule/collecting duct system exhibited a well-developed zonula occludens with anastomosing strands. The distal segment showed a narrow zonula occludens composed of few parallel strands. The structure of the occluding junctions along the renal tubule of this teleost displays several similarities with the pattern of the zonulae occludentes in the amphibian and the mammalian nephron. From these observations, in conjunction with available data from other vertebrate classes, it can be concluded that in the proximal tubule the development of a deep and complex zonula occludens is a general feature of cold-blooded vertebrates.     

Alterations in the distribution of glycoproteins in epithelial cells of murine colon after injection of tunicamycin

Summary Glycoproteins are associated with several structures of colonic absorptive cells of the mouse. These include the cell coat, Golgi apparatus and vesicles that transport the glycoproteins from the apparatus to the cell surface (Michaels and Leblond 1976). In many in vitro systems, the antibiotic tunicamycin inhibits the glycosylation of asparagine residues yielding carbohydrate-poor glycoproteins. In the present in vivo study, tunicamycin was injected into mice. The murine colonic epithelial cells were prepared routinely for electron microscopy and cytochemistry. Cells from the experimental and control animals were similar morphologically. However, staining by the periodic acid-chromic acid-silver methenamine technique, revealed differences in the distribution of glycoproteins. In animals that received the higher dosages of tunicamycin there was a substantial reduction in silver staining in both the Golgi apparatus and the vesicles of colonic epithelial cells compared to these structures in cells of identically treated control tissues, whereas the staining over the cell coat was not significantly altered. Possible explanations for the staining of the cell coat in the treated animals were provided in the text. This report demonstrates the feasibility of using tunicamycin in vivo and detection of the changes obtained by the silver methenamine method.     

Liquorkontaktneurone im Nucleus infundibularis

Zusammenfassung Der Nucleus infundibularis verschiedener Reptilien wurde licht- und elektronenmikroskopisch untersucht. Zellen dieses Kernes entsenden Fortsätze durch ein mehrreihiges Ependym in den 3. Ventrikel und bilden dort freie, intraventrikuläre Nervenendigungen (Liquorkontakt-Nervenendigungen, Lkne). Lichtmikroskopisch konnten in der Kerngruppe a) kleine, AChE-negative, toluidinblaue und b) große, AChE-positive, mit Toluidinblau hell erscheinende Nervenzellen unterschieden werden.Die knöpfchenförmigen LKNE weisen Elemente des endoplasmatischen Retikulums, freie Ribosomen, eine wechselnde Anzahl Mitochondrien, einzelne Lysosomen, asymmetrische Zilien (Typ 9+0) mit akzessorischem Basalkörper und Zilienwurzeln auf. Zwei LKNE-Typen sind unterscheidbar: a) LKNE mit granulierten Vesikeln mit einem Durchmesser von 800–1100 Å und b) LKNE mit großen, elektronendichten Granula (Durchmesser 1200–1600 Å).Im Lumen des 3. Ventrikels treten kleinkalibrige Axone auf, die kleine, granulierte Bläschen (Durchmesser 700–900 Å) enthalten und mit den LKNE des Nucleus infundibularis intraventrikuläre Synapsen bilden.Die Perikaryen des Nucleus infundibularis weisen ein reichliches endoplasmatisches Retikulum, zahlreiche Polyribosomen, Neurotubuli und Mitochondrien auf. Ähnlich wie bei den LKNE sind zwei Perikaryenarten zu unterscheiden: a) Perikaryen mit granulierten Vesikeln (Durchmesser 800–1100 Å) und b) solche mit elektronendichten Granula (1200–1700 Å). Außerdem kommen verschiedene Arten axosomatischer und axodendritischer Synapsen vor.Die Funktion der intraventrikulären Nervenendigungen und verschiedenen Synapsenarten in der Kerngruppe wird im Hinblick auf einen Informationsaustausch zwischen dem Liquor cerebrospinalis und dem Nucleus infundibularis diskutiert.

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Liquor contacting neurons in the infundibular nucleus

Summary The infundibular nucleus of various reptiles was studied light and electron microscopically. Cells of this nucleus send processes through a stratified ependyma into the 3rd ventricle where they form free, intraventricular nerve terminals (liquor contacting nerve endings, LCNE). In the nucleus, two kinds of neurons could be distinguished light microscopically: a) small, AChE-negative, toluidine blue neurons, and b) large, AChE-positive cells staining light with toluidine blue.The club shaped LCNE contain elements of the endoplasmic reticulum, free ribosomes, a various amount of mitochondria, and single lysosomes. The terminals bear asymmetrical cilia (type 9+0) supplied with accessory basal bodies and rootlet fibres. Two kinds of LCNE are demonstrable: a) LCNE containing dense-core vesicles with a diameter of about 800–1100 Å, and b) LCNE with large, electron-dense granules (diameter about 1,200–1,600 Å). In the lumen of the 3rd ventricle, there occur small axons that contain small granulated vesicles (diameter about 700–900 Å), and that form intraventricular synapses with the LCNE of the infundibular nucleus.The perikarya of the infundibular nucleus contain an abundant endoplasmic reticulum, numerous polyribosomes, neurotubules and mitochondria. Similarly to the LCNE, two kinds of perikarya can be distinguished: a) perikarya containing granulated vesicles (diameter about 800–1100 Å), and b) perikarya with electron-dense granules (diameter about 1200–1700 Å). Furthermore, different types of axosomatic and axodendritic synapses occur.The function of the intraventricular nerve terminals and the different types of synapses in the nucleus is discussed with regard to an exchange of informations between the cerebrospinal fluid and the infundibular nucleus.

     

山羊早期胚胎发育的超微结构研究

本实验以促卵泡刺激素(FSH)进行超排处理所得的胚胎为材料,首次对山羊附植前胚胎发育过程中的超微结构变化进行了系统的研究。结果表明:(1)在桑椹期以前,胚胎中大都为带帽线粒体,从此期开始这种线粒体明显减少;从四细胞期开始,出现基质浅具横嵴的线粒体,且以后各期逐步增多。具横嵴的线粒体可能由带帽线粒体的帽状泡消失后转变而来。(2)核仁从四细胞期开始网状化,以后网状化程度逐步增强,颗粒部明显增加。(3)间隙连结最早形成于4细胞期,紧密连结和桥粒分别从8细胞期开始出现。     

Ultrastructure of the salivary bladder of the nine-banded armadillo

Summary The nine-banded armadillo possesses a salivary bladder which is a dilated portion of the main duct of the submandibular gland at its origin. The wall of the bladder is composed of an epithelium, a submucosa and a thick coat of skeletal muscle. The ultrastructure of the epithelium reveals that it is complex and consists of three cell types: 1) principal cells, 2) light cells, and 3) basal cells. The general organization of the epithelium suggests that it is a transporting type of epithelium such as that found in the amphibian and reptilian urinary bladders and the mammalian gall bladder. The submucosa is composed primarily of densely-packed collagen fibers. The skeletal muscle is very vascular and richly innervated.This study was supported in part by a research grant from U.S.P.H.S. (GRS 5-S01-RR-05705)The authors wish to acknowledge the technical assistance of Elizabeth Underwood