Library

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    ISSN: 1432-2013
    Keywords: Platinum electrode ; Isolated perfused tubule ; Mouse ; Redox activity ; Uric acid ; Proximal tubule ; Probenecid ; Pyrazinamide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract The design and application of a micro-plantinum electrode for continuous monitoring of reducing activity in the isolated tubule preparation is described. The electrodes response to H2O2 up to 0.1 mmol/l, to uric acid up to 0.3 mmol/l, ascorbic acid up to 1.0 mmol/l and cysteine up to 2.0 mmol/l is almost linear. The electrode is insensitive to extracellular ions, to changes of pH (5.5–8.0), CO2 (1–10%) and O2 (1–100%). The reading of the electrodes is almost doubled when the temperature is increased from 20–40°C. When reducing substances are omitted from the perfusate for isolated perfused proximal tubules of the mouse, the reading is identical in perfusate and collected fluid, indicating that the tubular epithelium does not produce redox substances in sufficient amount to interfere with the electrode reading at flow rates ≈ 10 nl/min. When the tubule is perfused with solutions containing 0.3 mmol/l uric acid, the uric acid concentration in the collected fluid is 0.16±0.01 mmol/l after a contact time of 1.36±0.1 s, revealing net uric acid reabsorption. Adding probenecid to the luminal perfusion fluid, leads to a 37.5±1.0% increase of uric acid concentration in collected fluid, disclosing the inhibitory effect of probenecid on uric acid reabsorption. If 0.3 mmol/l uric acid is added to the bath, 0.017±0.002 mmol/l uric acid is detected in the luminal fluid. The entry of uric acid into the lumen is abolished by 10−4 mol/l pyrazinamide.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
  • 2
    Electronic Resource
    Electronic Resource
    Springer
    Pflügers Archiv 400 (1984), S. 388-392 
    ISSN: 1432-2013
    Keywords: Microelectrode ; Galactose ; Raffinose ; Isolated perfused tubule ; Mouse ; Proximal tubule ; Volume reabsorption ; Acetazolamide
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract Manufacture, properties and use of a micro enzyme electrode for continuous monitoring of volume fluxes in the isolated tubule preparation is described. The specific electrode is a galactose-oxidase enzyme electrode, which can be used to detect changes in raffinose concentrations. The electrode's response to raffinose is almost linear over concentrations from 0–12 mmol/l. The electrode equally responds to galactose as to raffinose but is insensitive to other sugars, to pH changes (from 6.0–8.0), CO2 (from 1–10%) and electrolytes tested. Reducing O2 from 100 to 10% and to 1%, leads to a reduction of the reading by 10% and 30%, respectively. The reading is almost doubled when the temperature is increased from 20–40° C. Furthermore, reducing agents such as uric acid and ascorbic acid interfere with the reading. If these substances and raffinose are omitted from the perfusate for isolated perfused proximal mouse tubules, the reading is identical in perfusate and collected fluid, indicating that the tubular epithelium does not produce substances in sufficient amounts to interfere with the electrode reading. After addition of 6 mmol/l raffinose to the perfusate the raffinose concentration in the collected fluid of 0.76±0.05 mm segments of straight proximal mouse tubules (perfusion rate = 3.4±0.45 nl/min) is 10.2±0.3 mmol/l, indicating a volume reabsorption of 1.5±0.3 nl/min. Peritubular application of acetazolamide reduces the volume reabsorption by 42±4%.
    Type of Medium: Electronic Resource
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...