ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

X
feed icon rss

Your email was sent successfully. Check your inbox.

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

Proceed reservation?

Export
Filter
  • sodium excretion  (1)
  • squid axon  (1)
  • 1985-1989  (2)
  • 1890-1899
  • 1988  (2)
  • 1
    Electronic Resource
    Electronic Resource
    Effects of arachidonic acid and the other long-chain fatty acids on the membrane currents in the squid giant axon (1988)
    Springer
    The journal of membrane biology 106 (1988), S. 141-147 
    Details
    ISSN: 1432-1424
    Keywords: arachidonic acid ; long-chain fatty acids ; membrane currents ; Na channel ; squid axon ; membrane excitation
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology
    Notes: Summary The effects of arachidonic acid and some other long-chain fatty acids on the ionic currents of the voltage-clamped squid giant axon were investigated using intracellular application of the test substances. The effects of these acids, which are usually insoluble in solution, were examined by using α-cyclodextrin as a solvent. α-cyclodextrin itself had no effect on the excitable membrane. Arachidonic acid mainly suppresses the Na current but has little effect on the K current. These effects are completely reversed after washing with control solution. The concentration required to suppress the peak inward current by 50% (ED50) was 0.18mm, which was 10 times larger than that of medium-chain fatty acids like 2-decenoic acid. The Hill number was 1.5 for arachidonic acid, which is almost the same value as for medium-chain fatty acids. This means that the mechanisms of the inhibition are similar in both long- and medium-chain fatty acids. When the long-chain fatty acids were compared, the efficacy of suppression of Na current was about the same value for arachidonic acid, docosatetraenoic acid and docosahexaenoic acid. The suppression effects of linoleic acid and linolenic acid on Na currents were one-third of that of arachidonic acid. Oleic acid had a small suppression effect and stearic acid had almost no effect on the Na current. The currents were fitted to equations similar to those proposed by Hodgkin and Huxley (Hodgkin, A.L., Huxley, A.F. (1952)J. Physiol (London) 117:500–544) and the change in the parameters of these equations in the presence of fatty acids were calculated. The curve of the steady-state activation parameter (m ∞) for the Na current against membrane potential and the time constant of activation (τ m ) were shifted 10 mV in a depolarizing direction by the application of fatty acids. The time constant for inactivation (τ h ) has almost unaffected by application of these fatty acids.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01871396
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    A Quantitative Method of Evaluating the Diuretic Response to Furosemide in Rats (1988)
    Springer
    Pharmaceutical research 5 (1988), S. 694-698 
    Details
    ISSN: 1573-904X
    Keywords: furosemide ; diuresis ; sodium excretion ; potassium excretion ; chloride excretion ; urinary excretion rate ; urinary electrolytes in rats
    Source: Springer Online Journal Archives 1860-2000
    Topics: Chemistry and Pharmacology
    Notes: Abstract Furosemide effects are usually evaluated by measuring the urinary excretion rate of Na+ (UVNa) in humans. In the present study, however, UVNa showed a nonlinear relationship with urine flow rate after intravenous injection of furosemide in rats. In contrast, when the urinary excretion rate of (Na+ + K+) (UVNa+K) was plotted against the urine flow rate, a linear regression line was observed, with small interindividual variations in normal rats and in rats with uranyl nitrate-induced acute renal failure (ARF). Piretanide, a loop diuretic, also showed a similar relationship, while other types of diuretics revealed different slope values for the relationship. Although the urinary excretion rate of Cl− (UVC1) vs UVNa+K is expected to show a linear relationship in normal rats, the correlation coefficient of the linear regression line was smaller than that of the urine flow rate vs UVNa+K. Further, the slope of UVC1 vs UVNa+K was slightly different in ARF rats. Therefore, UVNa+K provides a better quantitative measure of diuretic response to loop diuretics than UVNa or UVC1.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1023/A:1015999626133
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...