Glycosaminoglycans in separated tubules of the guinea-pig and rat kidney medulla

Summary Isolated tubules of the renal medulla of guinea-pig and rat contained glycosaminoglycans. 20–25% of the uronic acids corresponded to hyaluronic acid. In the guinea-pig, chondroitin and dermatan-sulfates accounted for at least 50% of the uronic acids, whereas, in the rat, heparan sulfates comprised 65–70% of them.Supported, in part, by CONICET, Argentina, Mrs N. Ramonda-Becerra assisted in the electrophoretic assays.     

Structural alterations in rat kidney proximal tubules perfused with fresh autologous serum

Summary Two min of intraluminal perfusion of the rat proximal tubules with autologous serum induced marked ultrastructural alterations including extensive cytoplasmic vesiculation due to swelling of rough endoplasmic reticulum cisternae and occasional extrusion of nuclei and cytoplasm into the lumen. Within 4 min pronounced vesiculation of mitochondria was observed. These findings are consistent with the notion that serum-induced inhibition of proximal tubular fluid absorption is due to cell lysis, presumably mediated by complement activation.Acknowledgment. This study was supported by NIH grants AM16258, AM27857, a New York Health Council grant, and a Veterans Administration Research grant.     

Structural alterations in rat kidney proximal tubules perfused with fresh autologous serum

Two min of intraluminal perfusion of the rat proximal tubules with autologous serum induced marked ultrastructural alterations including extensive cytoplasmic vesiculation due to swelling of rough endoplasmic reticulum cisternae and occasional extrusion of nuclei and cytoplasm into the lumen. Within 4 min pronounced vesiculation of mitochondria was observed. These findings are consistent with the notion that serum-induced inhibition of proximal tubular fluid absorption is due to cell lysis, presumably mediated by complement activation.     

Ultrastructural localization of arylsulfatase B in mitochondria of epithelial cells of the proximal convoluted tubules of the rat kidney

Résumé Des tissus de rats fixés par perfusion avec une solution de glutaraldéhyde et de DMSO ont permis de localiser le produit de réaction de l'arylsulfatase B dans les mitochondries ainsi que dans d'autres organites. Dans les mitochondries, l'arylsulfatase a été décelée entre les membranes externe et interne de même qu'à l'intérieur des crêtes. La matrice mitochondriale n'a donné aucune réaction.

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Supported by grants from Medical Research Council of Canada and the Muscular Dystrophy Association of Canada.     

Pressure and flow in proximal tubules of rat kidneys

Zusammenfassung An proximalen Harnkanälchen wurde die Strömungsgeschwindigkeit der Flüssigkeit bestimmt. Es wurde die Durchgangszeit eines Öltropfens durch einzelne Kanälchen gemessen. Der Druckabfall im Kanälchen wurde aus Durchgangszeit und Dimension des Kanälchens berechnet. Die beobachtete Strömungsgeschwindigkeit variierte von 0.1 bis fast 2.0 mm³/Stunde, der berechnete Druckabfall ergab ungefähr 2.5 mm Hg/cm.     

SEM surface morphology of the contractile cells in the rat seminiferous tubules

Summary The SEM observation of the basal surface of the contractile cells in the boundary tissue of the seminiferous tubule of the rat has revealed that the contractile cells are extremely flat, vary in shape from rectangular to hexagonal, and are arranged close to each other, in the fashion of a tiled floor, around the seminiferous epithelium.     

Antioxidant effects on prostaglandin synthesis in rabbit kidney medulla slices

Summary Sodium diethyldithiocarbamate, 2,6-di-tert-butylphenol and N,N-diphenyl-p-phenylenediamine inhibited the generation of medullary prostaglandin E, but 1,2-dimethoxyethane (OH scavenger) and 2,5-dimethylfuran (¹O₂ scavenger) stimulated basal prostaglandin E production 1.2–1.3-fold. These results suggest that the balance between formation and removal of cellular lipid peroxides sets a peroxide level that can regulate the rate of prostaglandin formation in cells.     

SEM surface morphology of the contractile cells in the rat seminiferous tubules.

The SEM observation of the basal surface of the contractile cells in the boundary tissue of the seminiferous tubule of the rat revealed that the contractile cells are extremely flat, vary in shape from rectangular to hexagonal, and are arranged close to each other, in the fashion of a tiled floor, around the seminiferous epithelium.     

Electrolyte transport in the seminiferous tubules of the rat studied by the stopped-flow microperfusion technique

Zusammenfassung Mit Hilfe der «stopped-flow»-Mikroperfusionstechnik wurden am Samenkanälchen Elektrolyttransportprozesse untersucht. Es wurde gefunden, dass die Kanälchen ein kaliumreiches Primärsekret bilden. Dieses unterscheidet sich in seiner Zusammensetzung von dem Sekret, das man gewöhnlich unter ungestörten Fliessbedingungen findet.

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This project was supported by the Rural Bank of Australia. One of us (R.D.H.) thanks the National Health and Medical Research Council of Australia for the award of a B.Sc. (med.) studentship for 1970.     

The composition of the renal medulla during natriuresis accompanying saline loading in the rat

Zusammenfassung In 38 Ratten wurde die Na- und Harnstoff-Konzentration im Gewebewasser der Nierenrinde, des Nierenmarks und der Papillenspitze nach einer Infusion von isotoner Kochsalzlösung festgestellt. Die Konzentration beider Stoffe war in der Papillenspitze und in dem Nierenmark bedeutend niedriger als bei den Kontrollratten.     

Leucine aminopeptidase in the foetal kidney of the rat

Zusammenfassung Histochemisch demonstrierbare Leucinaminopeptidase erschien in den letzten Tagen der Schwangerschaft in einzelnen Gruppen von Tubuli der Rinde der fötalen Rattenniere. Der grösste Teil der Rinde und das Mark erwiesen sich als negativ. Nach der Geburt verbreitete sich das Ferment über die ganze Rinde und vermehrte seine Aktivität stark.     

In vivo voltametric measurement of ascorbic acid and DOPAC in the striatum of the rat and guinea-pig

Differential pulse voltammetry was performed with electrochemically treated carbon fiber electrodes. By this technique, ascorbic acid and catechol compounds were resolved in vitro in two distinct peaks. Similar oxidation peaks were obtained in vivo from the striatum of Rats and Guinea-Pigs. From electrochemical and pharmacological observations it is suggested that they correspond to the oxidation of extracellular ascorbic acid and 3,4-dihydroxyphenyl acetic acid (DOPAC).     

Postnatal variations of the dry mass of neuronal nuclei of the spinal cord in rat and guinea-pig

Riassunto Sono state studiate per mezzo del microscapio ad interferenza Baker-Smith le variazioni di massa secca e volume del nuclei dei neuroni del rigonfiamento lombare del midollo spinale nel ratto e nella cavia in rapporto all'età.

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This investigation was supported by a grant to this Department from the Consiglio Nazionale delle Ricerche (No. 04/76/4/3482).