Library

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
  • 1
    Electronic Resource
    Electronic Resource
    A slowly inactivating transient outward current in rat ventricular myocytes (1993)
    Springer
    Pflügers Archiv 425 (1993), S. 184-186 
    Details
    ISSN: 1432-2013
    Keywords: voltage clamp ; transient outward current ; cardiac myocytes ; tetrodotoxin ; cadmium
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In rat ventricular myocytes we found two components of transient outward current, which could be discriminated time- and voltage-dependently. Besides the well known fastly inactivating transient outward current (ito,f, τ=35±8ms, n=4) we investigated properties of a slowly inactivating transient outward current (ito,s, τ=1.7±0.4s, n=4). Because of the slow inactivation process of ito,s tail currents were observed at −25mV. The inactivation curve of ito,f was characterized by a half-inactivation voltage of −58.4±1.4mV and a slope factor of 5.6±0.5mV (n=4). The inactivation curves of ito,s and tail currents were nearly identical but significantly different from the ito,f-curve. Half-inactivation voltages of ito,s and tail currents were −87.5±6mV and −89.1±5mV (n=4), respectively. Slope factors were 10.3±2.9mV and 9.8 ±1.7mV (n=4). The activation gate of ito,s was half-maximally opened at −11.5±2.6mV, and the slope factor was −10.6±1.7mV (n=3). ito,s tail current reversed its direction at −62±3.2mV (n=5). This indicates, that ito,s- current flow is carried mainly by potassium ions. Ito,s- current was not abolished by Tetrodotoxin (TTX) and Cd.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00374522
    Library Location Call Number Volume/Issue/Year Availability
    BibTip Others were also interested in ...
    Paper (German National Licenses)
    Fulltext
  • 2
    Electronic Resource
    Electronic Resource
    Modulation of action potential duration by inhibition of the transient outward current in sheep cardiac Purkinje fibers (1995)
    Springer
    Basic research in cardiology 90 (1995), S. 185-191 
    Details
    ISSN: 1435-1803
    Keywords: Sheep Purkinje fiber ; voltage-clamp ; action potential duration ; transient outward current ; 4-aminopyridine
    Source: Springer Online Journal Archives 1860-2000
    Topics: Medicine
    Notes: Abstract In sheep cardiac Purkinje fibers concentration-dependent inhibition of transient outward current (ito) by 4-aminopyridine (4-AP, 3-1000 μmol/l) was recorded with the two-microelectrode voltage-clamp technique, and correlated effects on action potential duration measured at — 70 mV (APD-70) were investigatigated. Half-maximal inhibition of ito-amplitude occurred at 15 μmol/l 4-AP. The drug exhibited no major effect on voltage-dependent control of inactivation but reduced the maximally available ito-current. At different activation frequencies (0.05 Hz, 0.25 Hz, 1 Hz) an equal amount of ito-current, measured as percentage of the respective control, was inhibited by 4-AP. The APD-70 was on the average increased by 4-AP (3–500 μmol/l) in a concentration-dependont manner up to 151 % of control. The drug-induced prolongation, measured as percentage of the respective control, was independent of stimulation frequency (0.05 Hz, 0.25 Hz, 1 Hz). Prolongation of APD-70 was on the average more pronounced for short action potentials (APD-70〈150 ms: 169 % of reference) than for longer ones (APD-70 150–300 ms: prolongation to 117 % of reference; 500 μmol/l 4-AP; 0.25 Hz stimulation rate). Few long control signals (APD-70 〉300 ms) were shortened by 4-AP. These results indicate that inhibition of ito-current by appropriate drugs will result in a reduction of inhomogeneity of action potential duration.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00805661
    Library Location Call Number Volume/Issue/Year 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...