adrenergic

(adjective)

containing or releasing adrenaline

Related Terms

Examples of adrenergic in the following topics:

  • Adrenergic Neurons and Receptors

    • Adrenergic receptors are molecules that bind catecholamines.
    • There are two main groups of adrenergic receptors, α and β, with several subtypes. α receptors have the subtypes α1 (a Gq coupled receptor) and α2 (a Gi coupled receptor).
    • Adrenaline or noradrenaline are receptor ligands to α1, α2, or β-adrenergic receptors (the pathway is shown in the following diagram).
    • α1-adrenergic receptors are members of the G protein-coupled receptor superfamily.
    • This schematic shows the mechanism of adrenergic receptors.

  • Epinephrine and Norepinephrine

    • Its actions vary by tissue type and tissue expression of adrenergic receptors.
    • Epinephrine acts by binding to a variety of adrenergic receptors.
    • Epinephrine is a nonselective agonist of all adrenergic receptors, including the major subtypes α1, α2, β1, β2, and β3.
    • When norepinephrine acts as a drug, it increases blood pressure by increasing vascular tone through α-adrenergic receptor activation.
    • The actions of norepinephrine are carried out via the binding to adrenergic receptors.

  • Local Regulation of Blood Flow

    • Generally, norepinephrine and epinephrine (hormones secreted by sympathetic nerves and the adrenal gland medulla) are vasoconstrictive, acting on alpha-1-adrenergic receptors.
    • However, the arterioles of skeletal muscle, cardiac muscle, and the pulmonary circulation vasodilate in response to these hormones acting on beta-adrenergic receptors.

  • Agonists, Antagonists, and Drugs

    • Beta blockers (sometimes written as β-blockers) or beta-adrenergic blocking agents, beta-adrenergic antagonists, beta-adrenoreceptor antagonists, or beta antagonists, are a class of drugs used for various indications.
    • As beta-adrenergic receptor antagonists, they diminish the effects of epinephrine (adrenaline) and other stress hormones.
    • Beta blockers block the action of endogenous catecholamines—epinephrine (adrenaline) and norepinephrine (noradrenaline) in particular—on β-adrenergic receptors, part of the sympathetic nervous system that mediates the fight-or-flight response.

  • Postganglionic Neurons

    • In the sympathetic division, most are adrenergic, meaning they use norepinephrine as their neurotransmitter.
    • In response to this stimulus, postganglionic neurons—with two important exceptions—release norepinephrine, which activates adrenergic receptors on the peripheral target tissues.

  • Autonomic Nervous System (ANS)

    • Recently, a third subsystem of neurons has been identified referred to as "non-adrenergic and non-cholinergic" neurons (because they use nitric oxide as a neurotransmitter).

  • Cell Signaling and Cellular Metabolism

    • The activation of β-adrenergic receptors in muscle cells by adrenaline leads to an increase in cyclic adenosine monophosphate (also known as cyclic AMP or cAMP) inside the cell .

  • Plasma Membrane Hormone Receptors

    • The amino acid-derived hormones epinephrine and norepinephrine bind to beta-adrenergic receptors on the plasma membrane of cells.

  • Heart Circulation

    • This mechanism is due to beta-adrenergic receptors in the coronary arteries and helps enable the increased cardiac output associated with fight-or-flight responses.