The localization of mutarotase in rat kidney.

The localization of mutarotase in rat kidney was investigated by fluorescein-labelled and peroxidase-labelled antibody techniques, and by method of isolation of the nuclei and cytoplasm in non-aqueous solvents. In these immunohistochemical studies, mutarotase was almost exclusively recognized in the nuclei of epithelial cells of renal tubules and glomeruli in rat. The specific activity of mutarotase was found to be 1.5 times higher in the nuclei (122 units/g dry wt) than that in the cytoplasm (80 units/g dry wt) isolated with non-aqueous solvents. These results suggest that mutarotase may be involved in the metabolism of D-glucose in nuclei.     

Circadian activity of rat kidney enzymes.

Alkaline phosphatase, LAP, beta-glucuronidase and cathepsin D activities and protein content of the kidney homogenate did not show any circadian rhythm in animals sacrificed at different hours of the day. The fluctuations of maltase appear modest and not dependent on a ligh/dark cycle.     

Parathion metabolism in rat liver and kidney slices

Zusammenfassung Es werden quantitative Angaben über die Bildung von Paraoxon aus Parathion und seine weitere Aufspaltung durch Inkubation mit Leber- und Nierenschnitten und Rattendarm gemacht. Unter der Voraussetzung, dass die Inkubation der Gewebeschnitte im wesentlichen den Verhältnissen im Organismus entsprechen, würde das die Umwandlung bewirkende Enzymsystem im Verlaufe von 24 h etwa 75% des anwesenden Parathions zu Paraoxon überführen.     

Location of dopamie stores in rat kidney

Summary In normotensive and genetically hypertensive Wistar rats, chronic renal denervation reduces renal cortical levels of noradrenaline and dopamine by more than 90%. Non-neural stores of renal dopamine are therefore small or absent.This work was supported by the National Heart Foundation of Australia, the National Health and Medical Research Council of Australia and the University of Melbourne. I wish to thank K. Mather and T. Harris for able technical assistance.     

The localization of mutarotase in rat kidney

Summary The localization of mutarotase in rat kidney was investigated by fluorescein-labelled and peroxidase-labelled antibody techniques, and by method of isolation of the nuclei and cytoplasm in non-aqueous solvents. In these immunohistochemical studies, mutarotase was almost exclusively recognized in the nuclei of epithelial cells of renal tubules and glomeruli in rat. The specific activity of mutarotase was found to be 1.5 times higher in the nuclei (122 units/g dry wt) than that in the cytoplasm (80 units/g dry wt) isolated with non-aqueous solvents. These results suggest that mutarotase may be involved in the metabolism of D-glucose in nuclei.Acknowledgment. The authors thank Prof. Y. Nishizuka (Department of Biochemistry, School of Medicine, Kobe University) for his valuable advice.     

Glucocorticoid and mineralocorticoid effects in rat liver and kidney

Zusammenfassung Die biochemischen Wirkungen von Aldosteron in der Rattenniere und Corticosteron in der Rattenleber wurden untersucht und der Mechanismus der Hormonwirkung diskutiert.     

Releasable GABA in tubular epithelium of rat kidney

Summary The distribution of gamma-aminobutyric acid (GABA) in the rat kidney was examined by immunocytochemical techniques. GABA-like immunoreactivity (GABA-LI) was predominantly confined to the renal tubules, including the ascending parts of the distal tubules, and the loops of Henle, the collecting tubules and ducts, and the connective parts of the convoluted tubules. In GABA-positive cortical tubules, about half of the epithelial cells were labelled. The labelled cell type showed the ultrastructural features of principal cells. Depolarizing stimulation by ouabain and high K⁺ concentration evoked the efflux of endogenous GABA from kidney slices. The present findings, along with previous results, suggest that GABA released from renal tubular epithelium, and transported with the urine, might be involved in the modulation of contractility in the urinary tract.     

Circadian activity of rat kidney enzymes

Summary Alkaline phosphatase, LAP, -glucuronidase and cathepsin D activities and protein content of the kidney homogenate did not show any circadian rhythm in animals sacrificed at different hours of the day. The fluctuations of maltase appear modest and not dependent on a light/dark cycle.     

Releasable GABA in tubular epithelium of rat kidney

The distribution of gamma-aminobutyric acid (GABA) in the rat kidney was examined by immunocytochemical techniques. GABA-like immunoreactivity (GABA-LI) was predominantly confined to the renal tubules, including the ascending parts of the distal tubules, and the loops of Henle, the collecting tubules and ducts, and the connective parts of the convoluted tubules. In GABA-positive cortical tubules, about half of the epithelial cells were labelled. The labelled cell type showed the ultrastructural features of principal cells. Depolarizing stimulation by ouabain and high K+ concentration evoked the efflux of endogenous GABA from kidney slices. The present findings, along with previous results, suggest that GABA released from renal tubular epithelium, and transported with the urine, might be involved in the modulation of contractility in the urinary tract.     

15-Hydroxyprostaglandin dehydrogenase and hexokinase in spontaneously hypertensive rat kidney

Summary 15-Hydroxyprostaglandin dehydrogenase (PGDH) surged in hypertensive (SHR) and normotensive (WKY) rat kidney at 8 days of age, is greatest in SHR. Hexokinase fell in SHR at 17 days of age, but thereafter was similar to WKY. This suggests multisystem enzymatic abnormalities in SHR kidney during development of hypertension.     

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

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.     

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.     

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.     

Insoluble zinc-precipitated phosphomonoesterase from rat kidney

Summary The insoluble form of phosphomonoesterase precipitated by means of Zn²⁺-ions was prepared from the partially purified extract of rat kidney. The freeze-dried preparation of the precipitated enzyme is highly active and is stable on heating at 100°C.