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R Taugner

Publications and source records attributed to R Taugner.

At least 109 records · Page 6Linked to original sources
PubMed1977

Studies on the juxtaglomerular apparatus. V. The juxtaglomerular apparatus in Tupaia with special reference to intercellular contacts.

The vascular pole of the juxtaglomerular apparatus in Tupaia belangeri was studied with special reference to the intercellular contacts of the periendothelial cells and the endothelium of the vas afferens. The periendothelial cells of the vascular pole of the glomerulum are connected by numerous gap junctions; and the granulated epithelial cells are suggested to form a functional unit. Probably there is a continuity of this system throughout the entire vascular pole including (1) all granulated cells, (2) all lacis cells, (3) the mesangium cells and (4) the adjacent smooth muscle cells of the vas afferens and vas efferens. Analysis of the endothelial junctions shows a zonular arrangement of tight junctions indicating a rather tight blood-tissue barrier next to the glomerular vascular pole; The ultrastructure of the different cell types of the vas afferens is also described, emphasizing the granulated epithelial cells and their innervation.

Animals↗
PubMed1976

Cell junctions in the epithelium of Bowman's capsule.

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.

Animals↗
PubMed1976

Arterial hypotension induced by horseradish peroxidase in various rat strains.

The influence of various commercial preparations of horseradish peroxidase upon the arterial pressure has been investigated using direct intra-arterial pressure recordings in Nembutal anesthetized rats of different strains. A marked hypotension was noted in Wistar and Sprague-Dawley rats when sufficiently high doses (5-10 mg/100 g body weight) were injected intravenously. This effect was observed with both highly purified (Sigma type VI, Boehringer Reinheitsgrad I) as well as less pure preparations (Sigma type II, Boehringer Reinheitsgrad II). Prior injection of promethazin, an antihistamine, prevented the drop in arterial pressure. Wistar/Furth rats appeared almost resistant to the hypotensive effect of Sigma preparations but developed moderate to marked hypotension with both types of Boehringer horseradish peroxidase. When instead of Nembutal, ether anesthesia was used only a transient mild hypotension developed and the animals recovered within 7-10 min. No effect was noted in Syrian hamsters receiving injections with the same doses of horseradish peroxidase. Electrophoresis revealed marked variations in the isozyme composition of different horseradish peroxidase preparations. Since the exact nature of the hypotensive agent remains unknown, it is suggested that the arterial pressure be monitored before extensive systematic application of this tracer in vascular permeability studies in rats.

Animals↗
PubMed1975

Studies on the juxtaglomerular apparatus. IV. Freeze-fracturing of membrane surfaces.

The juxtaglomerular apparatus of the rat was studied after freeze-fracturing with special respect to intercellular junctions. It was found that juxtaglomerular granulated cells of the vas afferens are interconnected by gap junctions to adjacent cells (granulated cells, possibly also smooth muscle cells). Gap junctions have also been found on the surface of lacis cells and mesangial cells. It is therefore concluded that these cells of the juxtaglomerular apparatus and the glomerulus--granulated cells (possibly also smooth muscle cells) of the vas afferens, lacis cells and mesangium cells--form a functional system reacting in a coordinated manner to physiological stimuli.

Animals↗
PubMed1975

The intrarenal distribution of 125I-albumin in the Syrian hamster.

The intrarenal distribution of radioiodinated human serum albumin (125RISA) after intravenous injection was studied in Syrian hamsters by scintillation counting and frozen section autoradiography. After 15, 30 and 60 min the virtual plasma albumin space in the renal cortex of the hamster represented 6.49, 7.13, and 8.06 percent respectively of the kidney tissue volume. From the cortex to the renal papilla the albumin space increased to about 30 percent of the tissue volume. In comparison to this the albumin space in the renal cortex of the rat was about 20% and in the renal papilla about 33% (11). Frozen section autoradiography indicated that the distribution of radioalbumin in the renal cortex of the Syrian hamster is limited mainly to the kidney vessels, being especially noticeable in the glomerular capillaries. Toward the papilla increasingly greater (mainly extratubular) activity could be observed not only intravascularly but also interstitially. In the cortex of the rat kidney, on the other hand, radioactive albumin was accumulated (probably by filtration and reabsorption) predominantly in the proximal tubular epithelium. Wtithin 30 min thekidneys of the rat excreted mor than 10 times as much 125I than the hamster kidneys. These results (substantially less cortical accumulation and urinary excretion of radioalbumin in the Syrian hamster) indicate that, in contrast to the rat, obviously much less albumin is filtered (and then accumulated by proximal reabsorption) by the Syrian hamster glomeruli. This suggests that the Syrian hamster kidney is more suitable than the rat kidney for determining the interstitial, cortical, albumin space.

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