Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Experiment Videos

Rate-dependent changes in extracellular potassium in the rabbit atrium

D L Kunze

    Circulation Research
    |July 1, 1977
    PubMed
    Summary

    Changes in heart rate alter extracellular potassium levels in rabbit atria. The Na-K pump plays a crucial role in regulating these potassium ion concentrations during cardiac activity.

    Related Concept Videos

    You might also read

    Related Articles

    Articles linked to this work by shared authors, journal, and citation graph.

    Sort by
    Same author

    Voltage-gated K+ channels in chemoreceptor sensory neurons of rat petrosal ganglion.

    Brain research·2001
    Same author

    Brain-derived neurotrophic factor acutely inhibits AMPA-mediated currents in developing sensory relay neurons.

    The Journal of neuroscience : the official journal of the Society for Neuroscience·2000
    Same author

    Opioid modulation of calcium current in cultured sensory neurons: mu-modulation of baroreceptor input.

    The American journal of physiology·1999
    Same author

    Molecular characterization of the human CRT-1 creatine transporter expressed in Xenopus oocytes.

    Archives of biochemistry and biophysics·1999
    Same author

    Contribution of the hyperpolarization-activated current to the resting membrane potential of rat nodose sensory neurons.

    The Journal of physiology·1998
    Same author

    Analysis of a Ca2+-activated K+ channel that mediates hyperpolarization via the thrombin receptor pathway.

    The American journal of physiology·1998

    Area of Science:

    • Cardiovascular Physiology
    • Electrophysiology
    • Cellular Ion Transport

    Background:

    • Extracellular potassium ([K+]0) is a critical determinant of cardiac electrophysiology and function.
    • Understanding how cardiac activity influences [K+]0 is essential for comprehending normal and pathological heart rhythms.

    Purpose of the Study:

    • To continuously measure extracellular potassium ion concentrations in isolated rabbit atria under varying rates of stimulation.
    • To investigate the role of the Na-K pump in regulating extracellular potassium levels during changes in cardiac rate.

    Main Methods:

    • Utilized double-barreled microelectrodes for continuous measurement of extracellular potassium in superfused rabbit atria.
    • Varied stimulation rates from quiescent to 300 beats/min to observe dynamic changes in [K+]0.
    • Manipulated bathing solution composition (zero potassium, ouabain, LiCl, reduced Po2) to assess Na-K pump function.

    Main Results:

    • Increased heart rate led to transient increases in extracellular potassium, with magnitudes correlating to the stimulation rate.
    • Upon cessation of stimulation, extracellular potassium initially decreased below baseline levels before returning to normal.
    • Inhibition of the Na-K pump (via ouabain, LiCl, low Po2, or zero external K+) prevented the normal decline in [K+]0 during stimulation and the subsequent undershoot.

    Conclusions:

    • The Na-K pump is actively involved in extruding potassium ions during increased cardiac activity.
    • The Na-K pump plays a significant role in maintaining stable extracellular potassium levels, preventing excessive accumulation during high heart rates and facilitating the post-stimulation decrease.

    Related Experiment Videos