Search Results - (Author, Cooperation:R. Willi)

2013-03-02

American Association for the Advancement of Science (AAAS)

0036-8075

1095-9203

Biology

Chemistry and Pharmacology

Computer Science

Medicine

Natural Sciences in General

Physics

Animals ; Cytokines/immunology ; Disease Models, Animal ; Female ; Humans ; Mental Disorders/*immunology ; Mice ; Mice, Inbred C57BL ; Poly I-C/immunology/pharmacology ; Pregnancy ; Prenatal Exposure Delayed Effects/*immunology/virology ; Puberty/*immunology ; Stress, Physiological/*immunology

1432-2013

Sorbitol ; Organic osmolytes ; Inner medullary collecting duct ; Aldose reductase ; Diabetes mellitus

Springer Online Journal Archives 1860-2000

Medicine

Abstract Intracellular accumulation of sorbitol, generated fromd-glucose via the aldose reductase pathway, is thought to play an important role in diabetic complications such as lens cataracts and neuropathy. In order to elucidate the effect of diabetes on the renal inner medulla, another sorbitol-rich tissue, male Wistar rats were treated with a single dose of streptozotocin (60 mg/kg body weight, i.p.). Six wecks later total inner medullary tissue (IM) or isolated inner medullary collecting duct (IMCD) cells were prepared. In diabetic IM tissue, sorbitol content was 1.8-fold higher than in control IM tissue (134±17 vs. 74±22 μmol/g tissue protein). Sorbitol production in both normal and diabetic IMCD cells was strongly dependent on extracellulard-glucose concentration. In normal cells, for example, sorbitol production was 90±9 μmol sorbitol/g protein x h at 45 mMd-glucose compared to 13±1 μmol/g protein x h at 5 mM. At identicald-glucose concentrations sorbitol synthesis in diabetic IMCD cells was, however, always significantly higher than in control cells (122% of control at 15 mM and 126% of control at 45 mM). In addition, aldose reductase activity in diabetic IM was found to be augmented. The maximal velocity was 4.2 times higher (97±22 U/g protein vs. 23±7 U/g protein) while theK m of the enzyme remained unchanged. Membrane permeability for sorbitol or the response to changes in extracellular osmolarity was not significantly different in diabetic IMCD cells and normal cells with correspondingly high intracellular sorbitol concentrations. Similarly the kinetic parameters ofd-glucose uptake were not altered by streptozotocin treatment. These results suggest that increased medullary sorbitol content in diabetic rats is a result of increased sorbitol synthesis due to a higher extracellulard-glucose concentration and augmented aldose reductase activity in face of an unaltered sorbitol permeability of the plasma membrane.

Electronic Resource

0009-2940

Chemistry ; Inorganic Chemistry

Wiley InterScience Backfile Collection 1832-2000

Chemistry and Pharmacology

Condensed Isoquinolines, IV. Syntheses with 3-Bromo- and 3-Hydrazino-s-triazolo[3.4-a]isoquinoline3-Bromo-s-triazolo[3.4-a]isoquinoline (2) or the unsubstituted s-triazolo[3.4-a]isoquinoline react with butyl lithium to afford the 3-lithio compound 4, which is stable at -70° and decomposes like the MgBr-salt at room temperature with cleavage of the triazolo ring to form l-aminoisoquinoline. From 2 and anthranilic acid 13-oxo-13H-isoquino[1′.2′ : 3.4]-s-triazolo[5.1-b]quinazoline (13) is obtained. N-acyl derivatives of 3-hydrazino-s-triazolo[3.4-a]iso-quinoline (14) cannot be cyclocondensed. 14 reacts with ethyl pyruvate to give via hydrazone 19 11-oxo-10-methyl-11H-as-triazino[4′.3′ : 1.5]-s-triazolo[3.4-a]isoquinoline (20). The thermal decomposition of 3-azido-s-triazolo[3.4-a]isoquinoline (22) in aniline leads to the phenylazo-derivative 23.

Aus 3-Brom-s-triazolo[3.4-a]isochinolin (2) oder dem unsubstituierten s-Triazolo[3.4-a]isochinolin und Butyllithium entsteht die bei -70° stabile 3-Lithium-Verbindung 4, die wie das MgBr-Salz 3 bei Raumtemperatur unter Spaltung des Triazolringes in 1-Amino-isochinolin übergeht. Aus 2 und Anthranilsäure wird 13-Oxo-13H-isochino[1′.2′ : 3.4]-s-triazolo[5.1-b]-chinazolin (13) bereitet. N-Acyl-Derivate von 3-Hydrazino-s-triazolo[3.4-a]isochinolin (14) lassen sich nicht cyclokondensieren. 14 liefert mit Brenztraubensäureester via Hydrazon 19 das 11-Oxo-10-methyl-1 1H-as-triazino[4′.3′:1.5]-s-triazolo[3.4-a]isochinolin (20). Der thermische Zerfall von 3-Azido-s-triazolo[3.4-a]isochinolin (22) in Anilin führt zum Benzolazo-Derivat 23.

Electronic Resource

1432-5217

Springer Online Journal Archives 1860-2000

Mathematics

Economics

Electronic Resource

article

1984

Schuljahr 07 ; Sekundarstufe I ; Hauptschule ; Unterrichtseinheit ; Tafelbild ; Unterrichtsmaterial ; Bruchrechnung ; Division (Math) ; Mathematikunterricht ; Multiplikation

Hauptschulmagazin, Bd. 9 (1984) H. 6, S. 43-46, 0724-3502

German