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

Tyrosine hydroxylase: activation by nerve stimulation.

V H Morgenroth, M Boadle-Biber, R H Roth

    Proceedings of the National Academy of Sciences of the United States of America
    |November 1, 1974
    PubMed
    Summary

    Electrical stimulation increases norepinephrine synthesis by activating tyrosine hydroxylase (TH). Calcium ions (Ca++) play a key role in this TH activation, mimicking nerve stimulation effects and enhancing neurotransmitter formation.

    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

    Susceptibility to a parkinsonian toxin varies during primate development.

    Experimental neurology·2012
    Same author

    Reduced locomotor responses to cocaine in ghrelin-deficient mice.

    Neuroscience·2011
    Same author

    Impact of methamphetamine on dopamine neurons in primates is dependent on age: implications for development of Parkinson's disease.

    Neuroscience·2011
    Same author

    Aged monkeys as a partial model for Parkinson's disease.

    Pharmacology, biochemistry, and behavior·2011
    Same author

    3,4-methylenedioxymethamphetamine (MDMA)-induced release of endogenous serotonin from the rat dorsal raphe nucleus in vitro: Effects of fluoxetine and tryptophan.

    Neurochemistry international·2010
    Same author

    Embryonic substantia nigra grafts in the mesencephalon send neurites to the host striatum in non-human primate after overexpression of GDNF.

    The Journal of comparative neurology·2009

    Area of Science:

    • Neuroscience
    • Biochemistry
    • Pharmacology

    Background:

    • Norepinephrine synthesis is accelerated by electrical stimulation in the guinea pig vas deferens.
    • The underlying molecular mechanism for enhanced norepinephrine formation is not fully understood.
    • Increased activity of tyrosine hydroxylase (TH) during nerve stimulation has been proposed.

    Purpose of the Study:

    • To investigate the molecular mechanism of enhanced norepinephrine synthesis during nerve stimulation.
    • To determine the role of tyrosine hydroxylase (TH) activity in this process.
    • To explore the involvement of calcium ions (Ca++) in TH activation.

    Main Methods:

    • Isolated crude tyrosine hydroxylase (TH) preparations from electrically stimulated or potassium-depolarized guinea pig vasa deferentia.

    Related Experiment Videos

  • Assay of TH activity in the presence and absence of calcium ions (Ca++) and EGTA.
  • Analysis of kinetic properties of TH, including substrate and cofactor affinity, and end-product inhibition.

    • Main Results:

    • Electrically stimulated or potassium-depolarized tissues showed increased TH activity compared to controls.
    • Increased TH activity was partially antagonized by EGTA and blocked by Ca++ removal.
    • Addition of Ca++ to isolated TH activated the enzyme, an effect reversed by EGTA.
    • Activation of TH by Ca++ or stimulation involved increased affinity for substrate/cofactor and decreased affinity for norepinephrine.

    Conclusions:

    • Enhanced norepinephrine formation during nerve stimulation results from tyrosine hydroxylase (TH) activation.
    • Calcium ions (Ca++) are directly involved in the activation of TH.
    • Nerve stimulation-induced Ca++ influx or mobilization may mediate TH activation, linking it to neurotransmitter release.